Programs & Examples On #Type conversion

Type conversion is the way of implicitly or explicitly changing an entity of one data type into another. This is done to take advantage of certain features of type hierarchies or type representations.

Can I convert long to int?

The following solution will truncate to int.MinValue/int.MaxValue if the value is out of Integer bounds.

myLong < int.MinValue ? int.MinValue : (myLong > int.MaxValue ? int.MaxValue : (int)myLong)

Converting string to double in C#

private double ConvertToDouble(string s)
    {
        char systemSeparator = Thread.CurrentThread.CurrentCulture.NumberFormat.CurrencyDecimalSeparator[0];
        double result = 0;
        try
        {
            if (s != null)
                if (!s.Contains(","))
                    result = double.Parse(s, CultureInfo.InvariantCulture);
                else
                    result = Convert.ToDouble(s.Replace(".", systemSeparator.ToString()).Replace(",", systemSeparator.ToString()));
        }
        catch (Exception e)
        {
            try
            {
                result = Convert.ToDouble(s);
            }
            catch
            {
                try
                {
                    result = Convert.ToDouble(s.Replace(",", ";").Replace(".", ",").Replace(";", "."));
                }
                catch {
                    throw new Exception("Wrong string-to-double format");
                }
            }
        }
        return result;
    }

and successfully passed tests are:

        Debug.Assert(ConvertToDouble("1.000.007") == 1000007.00);
        Debug.Assert(ConvertToDouble("1.000.007,00") == 1000007.00);
        Debug.Assert(ConvertToDouble("1.000,07") == 1000.07);
        Debug.Assert(ConvertToDouble("1,000,007") == 1000007.00);
        Debug.Assert(ConvertToDouble("1,000,000.07") == 1000000.07);
        Debug.Assert(ConvertToDouble("1,007") == 1.007);
        Debug.Assert(ConvertToDouble("1.07") == 1.07);
        Debug.Assert(ConvertToDouble("1.007") == 1007.00);
        Debug.Assert(ConvertToDouble("1.000.007E-08") == 0.07);
        Debug.Assert(ConvertToDouble("1,000,007E-08") == 0.07);

How can I convert a char to int in Java?

You can use static methods from Character class to get Numeric value from char.

char x = '9';

if (Character.isDigit(x)) { // Determines if the specified character is a digit.
    int y = Character.getNumericValue(x); //Returns the int value that the 
                                          //specified Unicode character represents.
    System.out.println(y);
}

Call int() function on every list element?

If you are intending on passing those integers to a function or method, consider this example:

sum(int(x) for x in numbers)

This construction is intentionally remarkably similar to list comprehensions mentioned by adamk. Without the square brackets, it's called a generator expression, and is a very memory-efficient way of passing a list of arguments to a method. A good discussion is available here: Generator Expressions vs. List Comprehension

How do I print bytes as hexadecimal?

I don't know of a better way than:

unsigned char byData[xxx]; 

int nLength = sizeof(byData) * 2;
char *pBuffer = new char[nLength + 1];
pBuffer[nLength] = 0;
for (int i = 0; i < sizeof(byData); i++)
{
    sprintf(pBuffer[2 * i], "%02X", byData[i]);
}

You can speed it up by using a Nibble to Hex method

unsigned char byData[xxx];

const char szNibbleToHex = { "0123456789ABCDEF" };

int nLength = sizeof(byData) * 2;
char *pBuffer = new char[nLength + 1];
pBuffer[nLength] = 0;
for (int i = 0; i < sizeof(byData); i++)
{
    // divide by 16
    int nNibble = byData[i] >> 4;
    pBuffer[2 * i]  = pszNibbleToHex[nNibble];

    nNibble = byData[i] & 0x0F;
    pBuffer[2 * i + 1]  = pszNibbleToHex[nNibble];

}

How do I check if a string is a number (float)?

In case you are looking for parsing (positive, unsigned) integers instead of floats, you can use the isdigit() function for string objects.

>>> a = "03523"
>>> a.isdigit()
True
>>> b = "963spam"
>>> b.isdigit()
False

String Methods - isdigit(): Python2, Python3

There's also something on Unicode strings, which I'm not too familiar with Unicode - Is decimal/decimal

Convert INT to VARCHAR SQL

CONVERT(DATA_TYPE , Your_Column) is the syntax for CONVERT method in SQL. From this convert function we can convert the data of the Column which is on the right side of the comma (,) to the data type in the left side of the comma (,) Please see below example.

SELECT CONVERT (VARCHAR(10), ColumnName) FROM TableName

How Do I Convert an Integer to a String in Excel VBA?

enter image description here

    Sub NumToText(ByRef sRng As String, Optional ByVal WS As Worksheet)
    '---Converting visible range form Numbers to Text
        Dim Temp As Double
        Dim vRng As Range
        Dim Cel As Object

        If WS Is Nothing Then Set WS = ActiveSheet
            Set vRng = WS.Range(sRng).SpecialCells(xlCellTypeVisible)
            For Each Cel In vRng
                If Not IsEmpty(Cel.Value) And IsNumeric(Cel.Value) Then
                    Temp = Cel.Value
                    Cel.ClearContents
                    Cel.NumberFormat = "@"
                    Cel.Value = CStr(Temp)
                End If
            Next Cel
    End Sub


    Sub Macro1()
        Call NumToText("A2:A100", ActiveSheet)
    End Sub

Reffer: MrExcel.com – Convert numbers to text with VBA

How to convert numbers between hexadecimal and decimal

Here is my function:

using System;
using System.Collections.Generic;
class HexadecimalToDecimal
{
    static Dictionary<char, int> hexdecval = new Dictionary<char, int>{
        {'0', 0},
        {'1', 1},
        {'2', 2},
        {'3', 3},
        {'4', 4},
        {'5', 5},
        {'6', 6},
        {'7', 7},
        {'8', 8},
        {'9', 9},
        {'a', 10},
        {'b', 11},
        {'c', 12},
        {'d', 13},
        {'e', 14},
        {'f', 15},
    };

    static decimal HexToDec(string hex)
    {
        decimal result = 0;
        hex = hex.ToLower();

        for (int i = 0; i < hex.Length; i++)
        {
            char valAt = hex[hex.Length - 1 - i];
            result += hexdecval[valAt] * (int)Math.Pow(16, i);
        }

        return result;
    }

    static void Main()
    {

        Console.WriteLine("Enter Hexadecimal value");
        string hex = Console.ReadLine().Trim();

        //string hex = "29A";
        Console.WriteLine("Hex {0} is dec {1}", hex, HexToDec(hex));

        Console.ReadKey();
    }
}

Convert columns to string in Pandas

One way to convert to string is to use astype:

total_rows['ColumnID'] = total_rows['ColumnID'].astype(str)

However, perhaps you are looking for the to_json function, which will convert keys to valid json (and therefore your keys to strings):

In [11]: df = pd.DataFrame([['A', 2], ['A', 4], ['B', 6]])

In [12]: df.to_json()
Out[12]: '{"0":{"0":"A","1":"A","2":"B"},"1":{"0":2,"1":4,"2":6}}'

In [13]: df[0].to_json()
Out[13]: '{"0":"A","1":"A","2":"B"}'

Note: you can pass in a buffer/file to save this to, along with some other options...

How to convert string to integer in C#

string varString = "15";
int i = int.Parse(varString);

or

int varI;
string varString = "15";
int.TryParse(varString, out varI);

int.TryParse is safer since if you put something else in varString (for example "fsfdsfs") you would get an exception. By using int.TryParse when string can't be converted into int it will return 0.

Convert Float to Int in Swift

There are lots of ways to round number with precision. You should eventually use swift's standard library method rounded() to round float number with desired precision.

To round up use .up rule:

let f: Float = 2.2
let i = Int(f.rounded(.up)) // 3

To round down use .down rule:

let f: Float = 2.2
let i = Int(f.rounded(.down)) // 2

To round to the nearest integer use .toNearestOrEven rule:

let f: Float = 2.2
let i = Int(f.rounded(.toNearestOrEven)) // 2

Be aware of the following example:

let f: Float = 2.5
let i = Int(roundf(f)) // 3
let j = Int(f.rounded(.toNearestOrEven)) // 2

Convert float to std::string in C++

Unless you're worried about performance, use string streams:

#include <sstream>
//..

std::ostringstream ss;
ss << myFloat;
std::string s(ss.str());

If you're okay with Boost, lexical_cast<> is a convenient alternative:

std::string s = boost::lexical_cast<std::string>(myFloat);

Efficient alternatives are e.g. FastFormat or simply the C-style functions.

How to convert integer to decimal in SQL Server query?

SELECT height/10.0 AS HeightDecimal FROM dbo.whatever;

If you want a specific precision scale, then say so:

SELECT CONVERT(DECIMAL(16,4), height/10.0) AS HeightDecimal
  FROM dbo.whatever;

How to convert a Date to a formatted string in VB.net?

I like:

Dim timeFormat As String = "yyyy-MM-dd HH:mm:ss"
myDate.ToString(timeFormat)

Easy to maintain if you need to use it in several parts of your code, date formats always seem to change sooner or later.

How to convert number of minutes to hh:mm format in TSQL?

declare function dbo.minutes2hours (
    @minutes int
)
RETURNS varchar(10)
as
begin
    return format(dateadd(minute,@minutes,'00:00:00'), N'HH\:mm','FR-fr')
end

Convert an integer to a byte array

Check out the "encoding/binary" package. Particularly the Read and Write functions:

binary.Write(a, binary.LittleEndian, myInt)

How can I convert a string with dot and comma into a float in Python

s =  "123,456.908"
print float(s.replace(',', ''))

PHP Converting Integer to Date, reverse of strtotime

Can you try this,

echo date("Y-m-d H:i:s", 1388516401);

As noted by theGame,

This means that you pass in a string value for the time, and optionally a value for the current time, which is a UNIX timestamp. The value that is returned is an integer which is a UNIX timestamp.

echo strtotime("2014-01-01 00:00:01");

This will return into the value 1388516401, which is the UNIX timestamp for the date 2014-01-01. This can be confirmed using the date() function as like below:

echo date('Y-m-d', 1198148400); // echos 2014-01-01

How to convert QString to std::string?

Best thing to do would be to overload operator<< yourself, so that QString can be passed as a type to any library expecting an output-able type.

std::ostream& operator<<(std::ostream& str, const QString& string) {
    return str << string.toStdString();
}

How to cast/convert pointer to reference in C++

foo(*ob);

You don't need to cast it because it's the same Object type, you just need to dereference it.

Difference between Convert.ToString() and .ToString()

To understand both the methods let's take an example:

int i =0;
MessageBox.Show(i.ToString());
MessageBox.Show(Convert.ToString(i)); 

Here both the methods are used to convert the string but the basic difference between them is: Convert function handles NULL, while i.ToString() does not it will throw a NULL reference exception error. So as good coding practice using convert is always safe.

Let's see another example:

string s;
object o = null;
s = o.ToString(); 
//returns a null reference exception for s. 

string s;
object o = null;
s = Convert.ToString(o); 
//returns an empty string for s and does not throw an exception.

Converting integer to digit list

you can use:

First convert the value in a string to iterate it, Them each value can be convert to a Integer value = 12345

l = [ int(item) for item in str(value) ]

Converting characters to integers in Java

Try any one of the below. These should work:

int a = Character.getNumericValue('3');
int a = Integer.parseInt(String.valueOf('3');

convert double to int

label8.Text = "" + years.ToString("00") + " years";

when you want to send it to a label, or something, and you don't want any fractional component, this is the best way

label8.Text = "" + years.ToString("00.00") + " years";

if you want with only 2, and it's always like that

How to convert a boolean array to an int array

Numpy arrays have an astype method. Just do y.astype(int).

Note that it might not even be necessary to do this, depending on what you're using the array for. Bool will be autopromoted to int in many cases, so you can add it to int arrays without having to explicitly convert it:

>>> x
array([ True, False,  True], dtype=bool)
>>> x + [1, 2, 3]
array([2, 2, 4])

How can I convert string to datetime with format specification in JavaScript?

Moment.js will handle this:

var momentDate = moment('23.11.2009 12:34:56', 'DD.MM.YYYY HH:mm:ss');
var date = momentDate.;

how to convert a string to a bool

Ignoring the specific needs of this question, and while its never a good idea to cast a string to a bool, one way would be to use the ToBoolean() method on the Convert class:

bool val = Convert.ToBoolean("true");

or an extension method to do whatever weird mapping you're doing:

public static class StringExtensions
{
    public static bool ToBoolean(this string value)
    {
        switch (value.ToLower())
        {
            case  "true":
                return true;
            case "t":
                return true;
            case "1":
                return true;
            case "0":
                return false;
            case "false":
                return false;
            case "f":
                return false;
            default:
                throw new InvalidCastException("You can't cast that value to a bool!");
        }
    }
}

How can I convert String to Int?

//May be quite some time ago but I just want throw in some line for any one who may still need it

int intValue;
string strValue = "2021";

try
{
    intValue = Convert.ToInt32(strValue);
}
catch
{
    //Default Value if conversion fails OR return specified error
    // Example 
    intValue = 2000;
}

How to convert UTF-8 byte[] to string?

string result = System.Text.Encoding.UTF8.GetString(byteArray);

Converting char[] to byte[]

Edit: Andrey's answer has been updated so the following no longer applies.

Andrey's answer (the highest voted at the time of writing) is slightly incorrect. I would have added this as comment but I am not reputable enough.

In Andrey's answer:

char[] chars = {'c', 'h', 'a', 'r', 's'}
byte[] bytes = Charset.forName("UTF-8").encode(CharBuffer.wrap(chars)).array();

the call to array() may not return the desired value, for example:

char[] c = "aaaaaaaaaa".toCharArray();
System.out.println(Arrays.toString(Charset.forName("UTF-8").encode(CharBuffer.wrap(c)).array()));

output:

[97, 97, 97, 97, 97, 97, 97, 97, 97, 97, 0]

As can be seen a zero byte has been added. To avoid this use the following:

char[] c = "aaaaaaaaaa".toCharArray();
ByteBuffer bb = Charset.forName("UTF-8").encode(CharBuffer.wrap(c));
byte[] b = new byte[bb.remaining()];
bb.get(b);
System.out.println(Arrays.toString(b));

output:

[97, 97, 97, 97, 97, 97, 97, 97, 97, 97]

As the answer also alluded to using passwords it might be worth blanking out the array that backs the ByteBuffer (accessed via the array() function):

ByteBuffer bb = Charset.forName("UTF-8").encode(CharBuffer.wrap(c));
byte[] b = new byte[bb.remaining()];
bb.get(b);
blankOutByteArray(bb.array());
System.out.println(Arrays.toString(b));

Convert a Unicode string to a string in Python (containing extra symbols)

>>> text=u'abcd'
>>> str(text)
'abcd'

If the string only contains ascii characters.

C++ floating point to integer type conversions

One thing I want to add. Sometimes, there can be precision loss. You may want to add some epsilon value first before converting. Not sure why that works... but it work.

int someint = (somedouble+epsilon);

What is the difference between Double.parseDouble(String) and Double.valueOf(String)?

If you want to convert string to double data type then most choose parseDouble() method. See the example code:

String str = "123.67";
double d = parseDouble(str);

You will get the value in double. See the StringToDouble tutorial at tutorialData.

How do I convert a String to an InputStream in Java?

Like this:

InputStream stream = new ByteArrayInputStream(exampleString.getBytes(StandardCharsets.UTF_8));

Note that this assumes that you want an InputStream that is a stream of bytes that represent your original string encoded as UTF-8.

For versions of Java less than 7, replace StandardCharsets.UTF_8 with "UTF-8".

Conversion from Long to Double in Java

Long i = 1000000;
String s = i + "";
Double d = Double.parseDouble(s);
Float f = Float.parseFloat(s);

This way we can convert Long type to Double or Float or Int without any problem because it's easy to convert string value to Double or Float or Int.

How to convert int to QString?

Yet another option is to use QTextStream and the << operator in much the same way as you would use cout in C++:

QPoint point(5,1);
QString str;
QTextStream(&str) << "Mouse click: (" << point.x() << ", " << point.y() << ").";

// OUTPUT:
// Mouse click: (5, 1).

Because operator <<() has been overloaded, you can use it for multiple types, not just int. QString::arg() is overloaded, for example arg(int a1, int a2), but there is no arg(int a1, QString a2), so using QTextStream() and operator << is convenient when formatting longer strings with mixed types.

Caution: You might be tempted to use the sprintf() facility to mimic C style printf() statements, but it is recommended to use QTextStream or arg() because they support Unicode strings.

Create ArrayList from array

If you use :

new ArrayList<T>(Arrays.asList(myArray));

you may create and fill two lists ! Filling twice a big list is exactly what you don't want to do because it will create another Object[] array each time the capacity needs to be extended.

Fortunately the JDK implementation is fast and Arrays.asList(a[]) is very well done. It create a kind of ArrayList named Arrays.ArrayList where the Object[] data points directly to the array.

// in Arrays
@SafeVarargs
public static <T> List<T> asList(T... a) {
    return new ArrayList<>(a);
}
//still in Arrays, creating a private unseen class
private static class ArrayList<E>

    private final E[] a;    
    ArrayList(E[] array) {
        a = array; // you point to the previous array
    }
    ....
}

The dangerous side is that if you change the initial array, you change the List ! Are you sure you want that ? Maybe yes, maybe not.

If not, the most understandable way is to do this :

ArrayList<Element> list = new ArrayList<Element>(myArray.length); // you know the initial capacity
for (Element element : myArray) {
    list.add(element);
}

Or as said @glglgl, you can create another independant ArrayList with :

new ArrayList<T>(Arrays.asList(myArray));

I love to use Collections, Arrays, or Guava. But if it don't fit, or you don't feel it, just write another inelegant line instead.

Converting from byte to int in java

Your array is of byte primitives, but you're trying to call a method on them.

You don't need to do anything explicit to convert a byte to an int, just:

int i=rno[0];

...since it's not a downcast.

Note that the default behavior of byte-to-int conversion is to preserve the sign of the value (remember byte is a signed type in Java). So for instance:

byte b1 = -100;
int i1 = b1;
System.out.println(i1); // -100

If you were thinking of the byte as unsigned (156) rather than signed (-100), as of Java 8 there's Byte.toUnsignedInt:

byte b2 = -100; // Or `= (byte)156;`
int = Byte.toUnsignedInt(b2);
System.out.println(i2); // 156

Prior to Java 8, to get the equivalent value in the int you'd need to mask off the sign bits:

byte b2 = -100; // Or `= (byte)156;`
int i2 = (b2 & 0xFF);
System.out.println(i2); // 156

Just for completeness #1: If you did want to use the various methods of Byte for some reason (you don't need to here), you could use a boxing conversion:

Byte b = rno[0]; // Boxing conversion converts `byte` to `Byte`
int i = b.intValue();

Or the Byte constructor:

Byte b = new Byte(rno[0]);
int i = b.intValue();

But again, you don't need that here.


Just for completeness #2: If it were a downcast (e.g., if you were trying to convert an int to a byte), all you need is a cast:

int i;
byte b;

i = 5;
b = (byte)i;

This assures the compiler that you know it's a downcast, so you don't get the "Possible loss of precision" error.

Easiest way to convert int to string in C++

C++11 introduced std::to_string() for numeric types:

int n = 123; // Input, signed/unsigned short/int/long/long long/float/double
std::string str = std::to_string(n); // Output, std::string

android - how to convert int to string and place it in a EditText?

Try using String.format() :

ed = (EditText) findViewById (R.id.box); 
int x = 10; 
ed.setText(String.format("%s",x)); 

Date Conversion from String to sql Date in Java giving different output?

That is the simple way of converting string into util date and sql date

String startDate="12-31-2014";
SimpleDateFormat sdf1 = new SimpleDateFormat("MM-dd-yyyy");
java.util.Date date = sdf1.parse(startDate);
java.sql.Date sqlStartDate = new java.sql.Date(date.getTime()); 

Leading zeros for Int in Swift

in Xcode 8.3.2, iOS 10.3 Thats is good to now

Sample1:

let dayMoveRaw = 5 
let dayMove = String(format: "%02d", arguments: [dayMoveRaw])
print(dayMove) // 05

Sample2:

let dayMoveRaw = 55 
let dayMove = String(format: "%02d", arguments: [dayMoveRaw])
print(dayMove) // 55

Convert bytes to int?

int.from_bytes( bytes, byteorder, *, signed=False )

doesn't work with me I used function from this website, it works well

https://coderwall.com/p/x6xtxq/convert-bytes-to-int-or-int-to-bytes-in-python

def bytes_to_int(bytes):
    result = 0
    for b in bytes:
        result = result * 256 + int(b)
    return result

def int_to_bytes(value, length):
    result = []
    for i in range(0, length):
        result.append(value >> (i * 8) & 0xff)
    result.reverse()
    return result

Converting Hexadecimal String to Decimal Integer

//package com.javatutorialhq.tutorial;

import java.util.Scanner;

/* * Java code convert hexadecimal to decimal */ 
public class HexToDecimal {

    public static void main(String[] args) {

        // TODO Auto-generated method stub 

        System.out.print("Hexadecimal Input:");

        // read the hexadecimal input from the console 

        Scanner s = new Scanner(System.in); 

        String inputHex = s.nextLine();

        try{ 

// actual conversion of hex to decimal

            Integer outputDecimal = Integer.parseInt(inputHex, 16);

            System.out.println("Decimal Equivalent : "+outputDecimal);


        }

        catch(NumberFormatException ne){

            // Printing a warning message if the input is not a valid hex number

            System.out.println("Invalid Input"); 

        }

        finally{ s.close();

        }
    } 
}

Convert a character digit to the corresponding integer in C

Just use the atol()function:

#include <stdio.h>
#include <stdlib.h>

int main() 
{
    const char *c = "5";
    int d = atol(c);
    printf("%d\n", d);

}

Setting a property by reflection with a string value

As several others have said, you want to use Convert.ChangeType:

propertyInfo.SetValue(ship,
    Convert.ChangeType(value, propertyInfo.PropertyType),
    null);

In fact, I recommend you look at the entire Convert Class.

This class, and many other useful classes are part of the System Namespace. I find it useful to scan that namespace every year or so to see what features I've missed. Give it a try!

How to convert string to float?

Why one should not use function atof() to convert string to double?

On success, atof() function returns the converted floating point number as a double value. If no valid conversion could be performed, the function returns zero (0.0). If the converted value would be out of the range of representable values by a double, it causes undefined behavior.

Refrence:http://www.cplusplus.com/reference/cstdlib/atof/

Instead use function strtod(), it is more robust.

Try this code:

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
int main()
{
    char s[100] = "4.0800";
    printf("Float value : %4.8f\n",strtod(s,NULL));
    return 0;
}

You will get the following output:

Float value : 4.08000000

Ruby: How to convert a string to boolean

Close to what is already posted, but without the redundant parameter:

class String
    def true?
        self.to_s.downcase == "true"
    end
end

usage:

do_stuff = "true"

if do_stuff.true?
    #do stuff
end

Retrieving the first digit of a number

    int number = 534;
    int firstDigit = Integer.parseInt(Integer.toString(number).substring(0, 1));

Convert byte[] to char[]

You must know the source encoding.

string someText = "The quick brown fox jumps over the lazy dog.";
byte[] bytes = Encoding.Unicode.GetBytes(someText);
char[] chars = Encoding.Unicode.GetChars(bytes);

Convert integer to hexadecimal and back again

NET FRAMEWORK

Very well explained and few programming lines GOOD JOB

// Store integer 182
int intValue = 182;
// Convert integer 182 as a hex in a string variable
string hexValue = intValue.ToString("X");
// Convert the hex string back to the number
int intAgain = int.Parse(hexValue, System.Globalization.NumberStyles.HexNumber);

PASCAL >> C#

http://files.hddguru.com/download/Software/Seagate/St_mem.pas

Something from the old school very old procedure of pascal converted to C #

    /// <summary>
    /// Conver number from Decadic to Hexadecimal
    /// </summary>
    /// <param name="w"></param>
    /// <returns></returns>
    public string MakeHex(int w)
    {
        try
        {
           char[] b =  {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
           char[] S = new char[7];

              S[0] = b[(w >> 24) & 15];
              S[1] = b[(w >> 20) & 15];
              S[2] = b[(w >> 16) & 15];
              S[3] = b[(w >> 12) & 15];
              S[4] = b[(w >> 8) & 15];
              S[5] = b[(w >> 4) & 15];
              S[6] = b[w & 15];

              string _MakeHex = new string(S, 0, S.Count());

              return _MakeHex;
        }
        catch (Exception ex)
        {

            throw;
        }
    }

Conversion from byte array to base64 and back

The reason the encoded array is longer by about a quarter is that base-64 encoding uses only six bits out of every byte; that is its reason of existence - to encode arbitrary data, possibly with zeros and other non-printable characters, in a way suitable for exchange through ASCII-only channels, such as e-mail.

The way you get your original array back is by using Convert.FromBase64String:

 byte[] temp_backToBytes = Convert.FromBase64String(temp_inBase64);

Convert data.frame column to a vector?

I'm going to attempt to explain this without making any mistakes, but I'm betting this will attract a clarification or two in the comments.

A data frame is a list. When you subset a data frame using the name of a column and [, what you're getting is a sublist (or a sub data frame). If you want the actual atomic column, you could use [[, or somewhat confusingly (to me) you could do aframe[,2] which returns a vector, not a sublist.

So try running this sequence and maybe things will be clearer:

avector <- as.vector(aframe['a2'])
class(avector) 

avector <- aframe[['a2']]
class(avector)

avector <- aframe[,2]
class(avector)

SQL Server: Error converting data type nvarchar to numeric

In case of float values with characters 'e' '+' it errors out if we try to convert in decimal. ('2.81104e+006'). It still pass ISNUMERIC test.

SELECT ISNUMERIC('2.81104e+006') 

returns 1.

SELECT convert(decimal(15,2), '2.81104e+006') 

returns

error: Error converting data type varchar to numeric.

And

SELECT try_convert(decimal(15,2), '2.81104e+006') 

returns NULL.

SELECT convert(float, '2.81104e+006') 

returns the correct value 2811040.

Convert string to nullable type (int, double, etc...)

Another thing to keep in mind is that the string itself might be null.

public static Nullable<T> ToNullable<T>(this string s) where T: struct
{
    Nullable<T> result = new Nullable<T>();
    try
    {
        if (!string.IsNullOrEmpty(s) && s.Trim().Length > 0)
        {
            TypeConverter conv = TypeDescriptor.GetConverter(typeof(T));
            result = (T)conv.ConvertFrom(s);
        }
    }
    catch { } 
    return result;
}

PostgreSQL: how to convert from Unix epoch to date?

On Postgres 10:

SELECT to_timestamp(CAST(epoch_ms as bigint)/1000)

Convert dataframe column to 1 or 0 for "true"/"false" values and assign to dataframe

Try this, it will convert True into 1 and False into 0:

data.frame$column.name.num  <- as.numeric(data.frame$column.name)

Then you can convert into factor if you want:

data.frame$column.name.num.factor <- as .factor(data.frame$column.name.num)

pandas dataframe convert column type to string or categorical

Prior answers focused on nominal data (e.g. unordered). If there is a reason to impose order for an ordinal variable, then one would use:

# Transform to category
df['zipcode_category'] = df['zipcode_category'].astype('category')

# Add ordered category
df['zipcode_ordered'] = df['zipcode_category']

# Setup the ordering
df.zipcode_ordered.cat.set_categories(
    new_categories = [90211, 90210], ordered = True, inplace = True
)

# Output IDs
df['zipcode_ordered_id'] = df.zipcode_ordered.cat.codes
print(df)
#  zipcode_category zipcode_ordered  zipcode_ordered_id
#            90210           90210                   1
#            90211           90211                   0

More details on setting ordered categories can be found at the pandas website:

https://pandas.pydata.org/pandas-docs/stable/user_guide/categorical.html#sorting-and-order

How to convert / cast long to String?

String strLong = Long.toString(longNumber);

Simple and works fine :-)

How do I parse a string to a float or int?

for number and char together :

string_for_int = "498 results should get"
string_for_float = "498.45645765 results should get"

first import re:

 import re

 #for get integer part:
 print(int(re.search(r'\d+', string_for_int).group())) #498

 #for get float part:
 print(float(re.search(r'\d+\.\d+', string_for_float).group())) #498.45645765

for easy model :

value1 = "10"
value2 = "10.2"
print(int(value1)) #10
print(float(value2)) #10.2

Import pandas dataframe column as string not int

Since pandas 1.0 it became much more straightforward. This will read column 'ID' as dtype 'string':

pd.read_csv('sample.csv',dtype={'ID':'string'})

As we can see in this Getting started guide, 'string' dtype has been introduced (before strings were treated as dtype 'object').

How to convert DateTime to a number with a precision greater than days in T-SQL?

SELECT CAST(CONVERT(datetime,'2009-06-15 23:01:00') as float)

yields 39977.9590277778

How to convert a char to a String?

I've tried the suggestions but ended up implementing it as follows

editView.setFilters(new InputFilter[]{new InputFilter()
        {
            @Override
            public CharSequence filter(CharSequence source, int start, int end,
                                       Spanned dest, int dstart, int dend)
            {
                String prefix = "http://";

                //make sure our prefix is visible
                String destination = dest.toString();

                //Check If we already have our prefix - make sure it doesn't
                //get deleted
                if (destination.startsWith(prefix) && (dstart <= prefix.length() - 1))
                {
                    //Yep - our prefix gets modified - try preventing it.
                    int newEnd = (dend >= prefix.length()) ? dend : prefix.length();

                    SpannableStringBuilder builder = new SpannableStringBuilder(
                            destination.substring(dstart, newEnd));
                    builder.append(source);
                    if (source instanceof Spanned)
                    {
                        TextUtils.copySpansFrom(
                                (Spanned) source, 0, source.length(), null, builder, newEnd);
                    }

                    return builder;
                }
                else
                {
                    //Accept original replacement (by returning null)
                    return null;
                }
            }
        }});

Int to Decimal Conversion - Insert decimal point at specified location

Simple math.

double result = ((double)number) / 100.0;

Although you may want to use decimal rather than double: decimal vs double! - Which one should I use and when?

How to convert NSData to byte array in iPhone?

That's because the return type for [data bytes] is a void* c-style array, not a Uint8 (which is what Byte is a typedef for).

The error is because you are trying to set an allocated array when the return is a pointer type, what you are looking for is the getBytes:length: call which would look like:

[data getBytes:&byteData length:len];

Which fills the array you have allocated with data from the NSData object.

How to convert an OrderedDict into a regular dict in python3

Here is what seems simplest and works in python 3.7

from collections import OrderedDict

d = OrderedDict([('method', 'constant'), ('data', '1.225')])
d2 = dict(d)  # Now a normal dict

Now to check this:

>>> type(d2)
<class 'dict'>
>>> isinstance(d2, OrderedDict)
False
>>> isinstance(d2, dict)
True

NOTE: This also works, and gives same result -

>>> {**d}
{'method': 'constant', 'data': '1.225'}
>>> {**d} == d2
True

As well as this -

>>> dict(d)
{'method': 'constant', 'data': '1.225'}
>>> dict(d) == {**d}
True

Cheers

Convert string to integer type in Go?

Converting Simple strings

The easiest way is to use the strconv.Atoi() function.

Note that there are many other ways. For example fmt.Sscan() and strconv.ParseInt() which give greater flexibility as you can specify the base and bitsize for example. Also as noted in the documentation of strconv.Atoi():

Atoi is equivalent to ParseInt(s, 10, 0), converted to type int.

Here's an example using the mentioned functions (try it on the Go Playground):

flag.Parse()
s := flag.Arg(0)

if i, err := strconv.Atoi(s); err == nil {
    fmt.Printf("i=%d, type: %T\n", i, i)
}

if i, err := strconv.ParseInt(s, 10, 64); err == nil {
    fmt.Printf("i=%d, type: %T\n", i, i)
}

var i int
if _, err := fmt.Sscan(s, &i); err == nil {
    fmt.Printf("i=%d, type: %T\n", i, i)
}

Output (if called with argument "123"):

i=123, type: int
i=123, type: int64
i=123, type: int

Parsing Custom strings

There is also a handy fmt.Sscanf() which gives even greater flexibility as with the format string you can specify the number format (like width, base etc.) along with additional extra characters in the input string.

This is great for parsing custom strings holding a number. For example if your input is provided in a form of "id:00123" where you have a prefix "id:" and the number is fixed 5 digits, padded with zeros if shorter, this is very easily parsable like this:

s := "id:00123"

var i int
if _, err := fmt.Sscanf(s, "id:%5d", &i); err == nil {
    fmt.Println(i) // Outputs 123
}

Convert boolean result into number/integer

Imho the best solution is:

fooBar | 0

This is used in asm.js to force integer type.

How to convert a string to a date in sybase

102 is the rule of thumb, convert (varchar, creat_tms, 102) > '2011'

Dynamically converting java object of Object class to a given class when class name is known

If you didnt know that mojb is of type MyClass, then how can you create that variable?

If MyClass is an interface type, or a super type, then there is no need to do a cast.

How to convert a double to long without casting?

Simply by the following:

double d = 394.000;
long l = d * 1L;

How do I convert a string to a number in PHP?

You can use:

((int) $var)   ( but in big number it return 2147483647 :-) )

But the best solution is to use:

if (is_numeric($var))
    $var = (isset($var)) ? $var : 0;
else
    $var = 0;

Or

if (is_numeric($var))
    $var = (trim($var) == '') ? 0 : $var;
else
    $var = 0;

How do I convert from int to String?

use Integer.toString(tmpInt).trim();

Checking if a string can be converted to float in Python

I used the function already mentioned, but soon I notice that strings as "Nan", "Inf" and it's variation are considered as number. So I propose you improved version of the function, that will return false on those type of input and will not fail "1e3" variants:

def is_float(text):
    # check for nan/infinity etc.
    if text.isalpha():
        return False
    try:
        float(text)
        return True
    except ValueError:
        return False

How to convert integer to string in C?

That's because itoa isn't a standard function. Try snprintf instead.

char str[LEN];
snprintf(str, LEN, "%d", 42);

Convert textbox text to integer

Suggest do this in your code-behind before sending down to SQL Server.

 int userVal = int.Parse(txtboxname.Text);

Perhaps try to parse and optionally let the user know.

int? userVal;
if (int.TryParse(txtboxname.Text, out userVal) 
{
  DoSomething(userVal.Value);
}
else
{ MessageBox.Show("Hey, we need an int over here.");   }

The exception you note means that you're not including the value in the call to the stored proc. Try setting a debugger breakpoint in your code at the time you call down into the code that builds the call to SQL Server.

Ensure you're actually attaching the parameter to the SqlCommand.

using (SqlConnection conn = new SqlConnection(connString))
{
    SqlCommand cmd = new SqlCommand(sql, conn);
    cmd.Parameters.Add("@ParamName", SqlDbType.Int);
    cmd.Parameters["@ParamName"].Value = newName;        
    conn.Open();
    string someReturn = (string)cmd.ExecuteScalar();        
}

Perhaps fire up SQL Profiler on your database to inspect the SQL statement being sent/executed.

Signed to unsigned conversion in C - is it always safe?

Horrible Answers Galore

Ozgur Ozcitak

When you cast from signed to unsigned (and vice versa) the internal representation of the number does not change. What changes is how the compiler interprets the sign bit.

This is completely wrong.

Mats Fredriksson

When one unsigned and one signed variable are added (or any binary operation) both are implicitly converted to unsigned, which would in this case result in a huge result.

This is also wrong. Unsigned ints may be promoted to ints should they have equal precision due to padding bits in the unsigned type.

smh

Your addition operation causes the int to be converted to an unsigned int.

Wrong. Maybe it does and maybe it doesn't.

Conversion from unsigned int to signed int is implementation dependent. (But it probably works the way you expect on most platforms these days.)

Wrong. It is either undefined behavior if it causes overflow or the value is preserved.

Anonymous

The value of i is converted to unsigned int ...

Wrong. Depends on the precision of an int relative to an unsigned int.

Taylor Price

As was previously answered, you can cast back and forth between signed and unsigned without a problem.

Wrong. Trying to store a value outside the range of a signed integer results in undefined behavior.

Now I can finally answer the question.

Should the precision of int be equal to unsigned int, u will be promoted to a signed int and you will get the value -4444 from the expression (u+i). Now, should u and i have other values, you may get overflow and undefined behavior but with those exact numbers you will get -4444 [1]. This value will have type int. But you are trying to store that value into an unsigned int so that will then be cast to an unsigned int and the value that result will end up having would be (UINT_MAX+1) - 4444.

Should the precision of unsigned int be greater than that of an int, the signed int will be promoted to an unsigned int yielding the value (UINT_MAX+1) - 5678 which will be added to the other unsigned int 1234. Should u and i have other values, which make the expression fall outside the range {0..UINT_MAX} the value (UINT_MAX+1) will either be added or subtracted until the result DOES fall inside the range {0..UINT_MAX) and no undefined behavior will occur.

What is precision?

Integers have padding bits, sign bits, and value bits. Unsigned integers do not have a sign bit obviously. Unsigned char is further guaranteed to not have padding bits. The number of values bits an integer has is how much precision it has.

[Gotchas]

The macro sizeof macro alone cannot be used to determine precision of an integer if padding bits are present. And the size of a byte does not have to be an octet (eight bits) as defined by C99.

[1] The overflow may occur at one of two points. Either before the addition (during promotion) - when you have an unsigned int which is too large to fit inside an int. The overflow may also occur after the addition even if the unsigned int was within the range of an int, after the addition the result may still overflow.

How to convert string to char array in C++?

Simplest way I can think of doing it is:

string temp = "cat";
char tab2[1024];
strcpy(tab2, temp.c_str());

For safety, you might prefer:

string temp = "cat";
char tab2[1024];
strncpy(tab2, temp.c_str(), sizeof(tab2));
tab2[sizeof(tab2) - 1] = 0;

or could be in this fashion:

string temp = "cat";
char * tab2 = new char [temp.length()+1];
strcpy (tab2, temp.c_str());

How to convert a number to string and vice versa in C++

In C++17, new functions std::to_chars and std::from_chars are introduced in header charconv.

std::to_chars is locale-independent, non-allocating, and non-throwing.

Only a small subset of formatting policies used by other libraries (such as std::sprintf) is provided.

From std::to_chars, same for std::from_chars.

The guarantee that std::from_chars can recover every floating-point value formatted by to_chars exactly is only provided if both functions are from the same implementation

 // See en.cppreference.com for more information, including format control.
#include <cstdio>
#include <cstddef>
#include <cstdlib>
#include <cassert>
#include <charconv>

using Type =  /* Any fundamental type */ ;
std::size_t buffer_size = /* ... */ ;

[[noreturn]] void report_and_exit(int ret, const char *output) noexcept 
{
    std::printf("%s\n", output);
    std::exit(ret);
}
void check(const std::errc &ec) noexcept
{
    if (ec ==  std::errc::value_too_large)
        report_and_exit(1, "Failed");
}
int main() {
    char buffer[buffer_size];        
    Type val_to_be_converted, result_of_converted_back;

    auto result1 = std::to_chars(buffer, buffer + buffer_size,  val_to_be_converted);
    check(result1.ec);
    *result1.ptr = '\0';

    auto result2 = std::from_chars(buffer, result1.ptr, result_of_converted_back);
    check(result2.ec);

    assert(val_to_be_converted == result_of_converted_back);
    report_and_exit(0, buffer);
}

Although it's not fully implemented by compilers, it definitely will be implemented.

How to convert from []byte to int in Go Programming

(reposting this answer)

You can use encoding/binary's ByteOrder to do this for 16, 32, 64 bit types

Play

package main

import "fmt"
import "encoding/binary"

func main() {
    var mySlice = []byte{244, 244, 244, 244, 244, 244, 244, 244}
    data := binary.BigEndian.Uint64(mySlice)
    fmt.Println(data)
}

SQL error "ORA-01722: invalid number"

Suppose telephone number is defined as NUMBER then the blanks cannot be converted into a number:

create table telephone_number (tel_number number);
insert into telephone_number values ('0419 853 694');

The above gives you a

ORA-01722: invalid number

Error: 'int' object is not subscriptable - Python

When you type x = 0 that is creating a new int variable (name) and assigning a zero to it.

When you type x[age1] that is trying to access the age1'th entry, as if x were an array.

java : convert float to String and String to float

well this method is not a good one, but easy and not suggested. Maybe i should say this is the least effective method and the worse coding practice but, fun to use,

float val=10.0;
String str=val+"";

the empty quotes, add a null string to the variable str, upcasting 'val' to the string type.

How to convert a data frame column to numeric type?

Though others have covered the topic pretty well, I'd like to add this additional quick thought/hint. You could use regexp to check in advance whether characters potentially consist only of numerics.

for(i in seq_along(names(df)){
     potential_numcol[i] <- all(!grepl("[a-zA-Z]",d[,i]))
}
# and now just convert only the numeric ones
d <- sapply(d[,potential_numcol],as.numeric)

For more sophisticated regular expressions and a neat why to learn/experience their power see this really nice website: http://regexr.com/

How could I convert data from string to long in c#

You can create your own conversion function:

    static long ToLong(string lNumber)
    {
        if (string.IsNullOrEmpty(lNumber))
            throw new Exception("Not a number!");
        char[] chars = lNumber.ToCharArray();
        long result = 0;
        bool isNegative = lNumber[0] == '-';
        if (isNegative && lNumber.Length == 1)
            throw new Exception("- Is not a number!");

        for (int i = (isNegative ? 1:0); i < lNumber.Length; i++)
        {
            if (!Char.IsDigit(chars[i]))
            {
                if (chars[i] == '.' && i < lNumber.Length - 1 && Char.IsDigit(chars[i+1]))
                {
                    var firstDigit = chars[i + 1] - 48;
                    return (isNegative ? -1L:1L) * (result + ((firstDigit < 5) ? 0L : 1L));    
                }
                throw new InvalidCastException($" {lNumber} is not a valid number!");
            }
            result = result * 10 + ((long)chars[i] - 48L);
        }
        return (isNegative ? -1L:1L) * result;
    }

It can be improved further:

  • performance wise
  • make the validation stricter in the sense that it currently doesn't care if characters after first decimal aren't digits
  • specify rounding behavior as parameter for conversion function. it currently does rounding

Converting an integer to a string in PHP

I would say it depends on the context. strval() or the casting operator (string) could be used. However, in most cases PHP will decide what's good for you if, for example, you use it with echo or printf...

One small note: die() needs a string and won't show any int :)

How to convert an Object {} to an Array [] of key-value pairs in JavaScript

You can use Object.keys() and map() to do this

_x000D_
_x000D_
var obj = {"1":5,"2":7,"3":0,"4":0,"5":0,"6":0,"7":0,"8":0,"9":0,"10":0,"11":0,"12":0}
var result = Object.keys(obj).map((key) => [Number(key), obj[key]]);

console.log(result);
_x000D_
_x000D_
_x000D_

cast class into another class or convert class to another

You have already defined the conversion, you just need to take it one step further if you would like to be able to cast. For example:

public class sub1
{
    public int a;
    public int b;
    public int c;

    public static explicit operator maincs(sub1 obj)
    {
        maincs output = new maincs() { a = obj.a, b = obj.b, c = obj.c };
        return output;
    }
}

Which then allows you to do something like

static void Main()
{
    sub1 mySub = new sub1();
    maincs myMain = (maincs)mySub;
}

How can I convert a string to a float in mysql?

This will convert to a numeric value without the need to cast or specify length or digits:

STRING_COL+0.0

If your column is an INT, can leave off the .0 to avoid decimals:

STRING_COL+0

Convert string into Date type on Python

from datetime import datetime

a = datetime.strptime(f, "%Y-%m-%d")

Converting String To Float in C#

First, it is just a presentation of the float number you see in the debugger. The real value is approximately exact (as much as it's possible).

Note: Use always CultureInfo information when dealing with floating point numbers versus strings.

float.Parse("41.00027357629127",
      System.Globalization.CultureInfo.InvariantCulture);

This is just an example; choose an appropriate culture for your case.

Converting Milliseconds to Minutes and Seconds?

Below code does the work for converting ms to min:secs with [m:ss] format

int seconds;
int minutes;
String Sec;
long Mills = ...;  // Milliseconds goes here
minutes = (int)(Mills / 1000)  / 60;
seconds = (int)((Mills / 1000) % 60);
Sec = seconds+"";

TextView.setText(minutes+":"+Sec);//Display duration [3:40]

Returning Month Name in SQL Server Query

Try this:

SELECT LEFT(DATENAME(MONTH,Getdate()),3)

Is true == 1 and false == 0 in JavaScript?

Ah, the dreaded loose comparison operator strikes again. Never use it. Always use strict comparison, === or !== instead.

Bonus fact: 0 == ''

Converting List<String> to String[] in Java

You want

String[] strarray = strlist.toArray(new String[0]);

See here for the documentation and note that you can also call this method in such a way that it populates the passed array, rather than just using it to work out what type to return. Also note that maybe when you print your array you'd prefer

System.out.println(Arrays.toString(strarray));

since that will print the actual elements.

How to convert NUM to INT in R?

Use as.integer:

set.seed(1)
x <- runif(5, 0, 100)
x
[1] 26.55087 37.21239 57.28534 90.82078 20.16819


as.integer(x)
[1] 26 37 57 90 20

Test for class:

xx <- as.integer(x)
str(xx)
 int [1:5] 26 37 57 90 20

Get first letter of a string from column

Cast the dtype of the col to str and you can perform vectorised slicing calling str:

In [29]:
df['new_col'] = df['First'].astype(str).str[0]
df

Out[29]:
   First  Second new_col
0    123     234       1
1     22    4353       2
2     32     355       3
3    453     453       4
4     45     345       4
5    453     453       4
6     56      56       5

if you need to you can cast the dtype back again calling astype(int) on the column

How to initialize an array's length in JavaScript?

The shortest:

_x000D_
_x000D_
let arr = [...Array(10)];
console.log(arr);
_x000D_
_x000D_
_x000D_

Import .bak file to a database in SQL server

Instead of choosing Restore Database..., select Restore Files and Filegroups...

Then enter a database name, select your .bak file path as the source, check the restore checkbox, and click Ok. If the .bak file is valid, it will work.

(The SQL Server restore option names are not intuitive for what should a very simple task.)

What is the difference between signed and unsigned int

As you are probably aware, ints are stored internally in binary. Typically an int contains 32 bits, but in some environments might contain 16 or 64 bits (or even a different number, usually but not necessarily a power of two).

But for this example, let's look at 4-bit integers. Tiny, but useful for illustration purposes.

Since there are four bits in such an integer, it can assume one of 16 values; 16 is two to the fourth power, or 2 times 2 times 2 times 2. What are those values? The answer depends on whether this integer is a signed int or an unsigned int. With an unsigned int, the value is never negative; there is no sign associated with the value. Here are the 16 possible values of a four-bit unsigned int:

bits  value
0000    0
0001    1
0010    2
0011    3
0100    4
0101    5
0110    6
0111    7
1000    8
1001    9
1010   10
1011   11
1100   12
1101   13
1110   14
1111   15

... and Here are the 16 possible values of a four-bit signed int:

bits  value
0000    0
0001    1
0010    2
0011    3
0100    4
0101    5
0110    6
0111    7
1000   -8
1001   -7
1010   -6
1011   -5
1100   -4
1101   -3
1110   -2
1111   -1

As you can see, for signed ints the most significant bit is 1 if and only if the number is negative. That is why, for signed ints, this bit is known as the "sign bit".

How to scroll the page when a modal dialog is longer than the screen?

position:fixed implies that, well, the modal window will remain fixed relative to the viewpoint. I agree with your assessment that it's appropriate in this scenario, with that in mind why don'y you add a scrollbar to the modal window itself?

If so, correct max-height and overflow properties should do the trick.

.NET DateTime to SqlDateTime Conversion

If you are checking for DBNULL, converting a SQL Datetime to a .NET DateTime should not be a problem. However, you can run into problems converting a .NET DateTime to a valid SQL DateTime.

SQL Server does not recognize dates prior to 1/1/1753. Thats the year England adopted the Gregorian Calendar. Usually checking for DateTime.MinValue is sufficient, but if you suspect that the data could have years before the 18th century, you need to make another check or use a different data type. (I often wonder what Museums use in their databases)

Checking for max date is not really necessary, SQL Server and .NET DateTime both have a max date of 12/31/9999 It may be a valid business rule but it won't cause a problem.

Fastest way to add an Item to an Array

For those who didn't know what next, just add new module file and put @jor code (with my little hacked, supporting 'nothing' array) below.

Module ArrayExtension
    <Extension()> _
    Public Sub Add(Of T)(ByRef arr As T(), item As T)
        If arr IsNot Nothing Then
            Array.Resize(arr, arr.Length + 1)
            arr(arr.Length - 1) = item
        Else
            ReDim arr(0)
            arr(0) = item
        End If

    End Sub
End Module

How would I extract a single file (or changes to a file) from a git stash?

On the git stash manpage you can read (in the "Discussion" section, just after "Options" description) that:

A stash is represented as a commit whose tree records the state of the working directory, and its first parent is the commit at HEAD when the stash was created.

So you can treat stash (e.g. stash@{0} is first / topmost stash) as a merge commit, and use:

$ git diff stash@{0}^1 stash@{0} -- <filename>

Explanation: stash@{0}^1 means the first parent of the given stash, which as stated in the explanation above is the commit at which changes were stashed away. We use this form of "git diff" (with two commits) because stash@{0} / refs/stash is a merge commit, and we have to tell git which parent we want to diff against. More cryptic:

$ git diff stash@{0}^! -- <filename>

should also work (see git rev-parse manpage for explanation of rev^! syntax, in "Specifying ranges" section).

Likewise, you can use git checkout to check a single file out of the stash:

$ git checkout stash@{0} -- <filename>

or to save it under another filename:

$ git show stash@{0}:<full filename>  >  <newfile>

or

$ git show stash@{0}:./<relative filename> > <newfile>

(note that here <full filename> is full pathname of a file relative to top directory of a project (think: relative to stash@{0})).


You might need to protect stash@{0} from shell expansion, i.e. use "stash@{0}" or 'stash@{0}'.

Pie chart with jQuery

There is a new player in the field, offering advanced Navigation Charts that are using Canvas for super-smooth animations and performance:

https://zoomcharts.com/

Example of charts:

interactive pie chart

Documentation: https://zoomcharts.com/en/javascript-charts-library/charts-packages/pie-chart/

What is cool about this lib:

  • Others slice can be expanded
  • Pie offers drill down for hierarchical structures (see example)
  • write your own data source controller easily, or provide simple json file
  • export high res images out of box
  • full touch support, works smoothly on iPad, iPhone, android, etc.

enter image description here

Charts are free for non-commercial use, commercial licenses and technical support available as well.

Also interactive Time charts and Net Charts are there for you to use. enter image description here

enter image description here

Charts come with extensive API and Settings, so you can control every aspect of the charts.

Error handling in getJSON calls

Why not

getJSON('get.php',{cmd:"1", typeID:$('#typesSelect')},function(data) {
    // ...
});

function getJSON(url,params,callback) {
    return $.getJSON(url,params,callback)
        .fail(function(jqXMLHttpRequest,textStatus,errorThrown) {
            console.dir(jqXMLHttpRequest);
            alert('Ajax data request failed: "'+textStatus+':'+errorThrown+'" - see javascript console for details.');
        })
}

??

For details on the used .fail() method (jQuery 1.5+), see http://api.jquery.com/jQuery.ajax/#jqXHR

Since the jqXHR is returned by the function, a chaining like

$.when(getJSON(...)).then(function() { ... });

is possible.

Copy files to network computers on windows command line

Below command will work in command prompt:

copy c:\folder\file.ext \\dest-machine\destfolder /Z /Y

To Copy all files:

copy c:\folder\*.* \\dest-machine\destfolder /Z /Y

Python Pylab scatter plot error bars (the error on each point is unique)

>>> import matplotlib.pyplot as plt
>>> a = [1,3,5,7]
>>> b = [11,-2,4,19]
>>> plt.pyplot.scatter(a,b)
>>> plt.scatter(a,b)
<matplotlib.collections.PathCollection object at 0x00000000057E2CF8>
>>> plt.show()
>>> c = [1,3,2,1]
>>> plt.errorbar(a,b,yerr=c, linestyle="None")
<Container object of 3 artists>
>>> plt.show()

where a is your x data b is your y data c is your y error if any

note that c is the error in each direction already

How do I print the content of httprequest request?

More details that help in logging

    String client = request.getRemoteAddr();
    logger.info("###### requested client: {} , Session ID : {} , URI :" + request.getMethod() + ":" + request.getRequestURI() + "", client, request.getSession().getId());

    Map params = request.getParameterMap();
    Iterator i = params.keySet().iterator();
    while (i.hasNext()) {
        String key = (String) i.next();
        String value = ((String[]) params.get(key))[0];
        logger.info("###### Request Param Name : {} , Value :  {} ", key, value);
    }

Error: "Adb connection Error:An existing connection was forcibly closed by the remote host"

Change to another USB port works for me. I tried reset ADB, but problem still there.

A completely free agile software process tool

Trello.com Trello is free for unlimited users. Period.

You almost definitely don't need "Sub-cards". Use the checklists instead, or if you REALLY need sub-cards, don't have a parent sub-card. Just name the tickets something like "Epic - Story A" or "Story - task Z" or whatever.

Another idea is to create two boards (did I mention you can have unlimited boards for free too?). One for your epics and one for your stories. Call one your product management board and the other your sprint board, or whatever you like.

I'm not sure what you need different roles for - but, people aren't crazy - they know their job. As a startup if you already have problems getting people to not do crazy things (Where you need to restrict their permissions) you have much much bigger issues.

The point is that you need a SMALL tool to help you track stuff. Not a super rigid tool that makes you work in a super specific way. As a new (I assume?) startup, you should let your process grow into a tool. Don't beef up your process to fit a tool.

Bogus foreign key constraint fail

Cannot delete or update a parent row: a foreign key constraint fails (table1.user_role, CONSTRAINT FK143BF46A8dsfsfds@#5A6BD60 FOREIGN KEY (user_id) REFERENCES user (id))

What i did in two simple steps . first i delete the child row in child table like

mysql> delete from table2 where role_id = 2 && user_id =20;

Query OK, 1 row affected (0.10 sec)

and second step as deleting the parent

delete from table1 where id = 20;

Query OK, 1 row affected (0.12 sec)

By this i solve the Problem which means Delete Child then Delete parent

i Hope You got it. :)

Android MediaPlayer Stop and Play

You should use only one mediaplayer object

    public class PlayaudioActivity extends Activity {

        private MediaPlayer mp;

        /** Called when the activity is first created. */
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
            Button b = (Button) findViewById(R.id.button1);
            Button b2 = (Button) findViewById(R.id.button2);
            final TextView t = (TextView) findViewById(R.id.textView1);

            b.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    stopPlaying();
                    mp = MediaPlayer.create(PlayaudioActivity.this, R.raw.far);
                    mp.start();
                }

            });

            b2.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    stopPlaying();
                    mp = MediaPlayer.create(PlayaudioActivity.this, R.raw.beet);
                    mp.start();
                }
            });
        }

        private void stopPlaying() {
            if (mp != null) {
                mp.stop();
                mp.release();
                mp = null;
           }
        }
    }

How do I add one month to current date in Java?

tl;dr

LocalDate::plusMonths

Example:

LocalDate.now( )
         .plusMonths( 1 );

Better to specify time zone.

LocalDate.now( ZoneId.of( "America/Montreal" )
         .plusMonths( 1 );

java.time

The java.time framework is built into Java 8 and later. These classes supplant the old troublesome date-time classes such as java.util.Date, .Calendar, & java.text.SimpleDateFormat. The Joda-Time team also advises migration to java.time.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations.

Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport and further adapted to Android in ThreeTenABP.

Date-only

If you want the date-only, use the LocalDate class.

ZoneId z = ZoneId.of( "America/Montreal" );
 LocalDate today = LocalDate.now( z );

today.toString(): 2017-01-23

Add a month.

LocalDate oneMonthLater = today.plusMonths( 1 );

oneMonthLater.toString(): 2017-02-23

Date-time

Perhaps you want a time-of-day along with the date.

First get the current moment in UTC with a resolution of nanoseconds.

Instant instant = Instant.now();

Adding a month means determining dates. And determining dates means applying a time zone. For any given moment, the date varies around the world with a new day dawning earlier to the east. So adjust that Instant into a time zone.

ZoneId zoneId = ZoneId.of( "America/Montreal" );
ZonedDateTime zdt = ZonedDateTime.ofInstant( instant , zoneId );

Now add your month. Let java.time handle Leap month, and the fact that months vary in length.

ZonedDateTime zdtMonthLater = zdt.plusMonths( 1 );

You might want to adjust the time-of-day to the first moment of the day when making this kind of calculation. That first moment is not always 00:00:00.0 so let java.time determine the time-of-day.

ZonedDateTime zdtMonthLaterStartOfDay = zdtMonthLater.toLocalDate().atStartOfDay( zoneId );

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

Where to obtain the java.time classes?

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.


Joda-Time

Update: The Joda-Time project is now in maintenance mode. Its team advises migration to the java.time classes. I am leaving this section intact for posterity.

The Joda-Time library offers a method to add months in a smart way.

DateTimeZone timeZone = DateTimeZone.forID( "Europe/Paris" );
DateTime now = DateTime.now( timeZone );
DateTime nextMonth = now.plusMonths( 1 );

You might want to focus on the day by adjust the time-of-day to the first moment of the day.

DateTime nextMonth = now.plusMonths( 1 ).withTimeAtStartOfDay();

Loop through an array in JavaScript

Yes, you can do the same in JavaScript using a loop, but not limited to that. There are many ways to do a loop over arrays in JavaScript. Imagine you have this array below, and you'd like to do a loop over it:

var arr = [1, 2, 3, 4, 5];

These are the solutions:

1) For loop

A for loop is a common way looping through arrays in JavaScript, but it is no considered as the fastest solutions for large arrays:

for (var i=0, l=arr.length; i<l; i++) {
  console.log(arr[i]);
}

2) While loop

A while loop is considered as the fastest way to loop through long arrays, but it is usually less used in the JavaScript code:

let i=0;

while (arr.length>i) {
    console.log(arr[i]);
    i++;
}

3) Do while
A do while is doing the same thing as while with some syntax difference as below:

let i=0;
do {
  console.log(arr[i]);
  i++;
}
while (arr.length>i);

These are the main ways to do JavaScript loops, but there are a few more ways to do that.

Also we use a for in loop for looping over objects in JavaScript.

Also look at the map(), filter(), reduce(), etc. functions on an Array in JavaScript. They may do things much faster and better than using while and for.

This is a good article if you like to learn more about the asynchronous functions over arrays in JavaScript.

Functional programming has been making quite a splash in the development world these days. And for good reason: Functional techniques can help you write more declarative code that is easier to understand at a glance, refactor, and test.

One of the cornerstones of functional programming is its special use of lists and list operations. And those things are exactly what the sound like they are: arrays of things, and the stuff you do to them. But the functional mindset treats them a bit differently than you might expect.

This article will take a close look at what I like to call the "big three" list operations: map, filter, and reduce. Wrapping your head around these three functions is an important step towards being able to write clean functional code, and opens the doors to the vastly powerful techniques of functional and reactive programming.

It also means you'll never have to write a for loop again.

Read more>> here:

how to set active class to nav menu from twitter bootstrap

$( ".nav li" ).click(function() {
        $('.nav li').removeClass('active');
        $(this).addClass('active');
    });

check this out.

FB OpenGraph og:image not pulling images (possibly https?)

Some properties can have extra metadata attached to them. These are specified in the same way as other metadata with property and content, but the property will have extra :

The og:image property has some optional structured properties:

  • og:image:url - Identical to og:image.
  • og:image:secure_url - An alternate url to use if the webpage requires HTTPS.
  • og:image:type - A MIME type for this image.
  • og:image:width - The number of pixels wide.
  • og:image:height - The number of pixels high.

A full image example:

<meta property="og:image" content="http://example.com/ogp.jpg" />
<meta property="og:image:secure_url" content="https://secure.example.com/ogp.jpg" /> 
<meta property="og:image:type" content="image/jpeg" /> 
<meta property="og:image:width" content="400" /> 
<meta property="og:image:height" content="300" />

So you need to change og:image property for your HTTPS URLs to og:image:secure_url

Ex:

HTTPS META TAG FOR IMAGE:

<meta property="og:image:secure_url" content="https://www.[YOUR SITE].com/images/shirts/overdriven-blues-music-tshirt-details-black.png" />

HTTP META TAG FOR IMAGE:

<meta property="og:image" content="http://www.[YOUR SITE].com/images/shirts/overdriven-blues-music-tshirt-details-black.png" />

Source: http://ogp.me/#structured <-- You can visit this site for more information.

Hope this helps you.

EDIT: Don't forget to ping facebook servers after updating your codes - URL Linter

Force Internet Explorer to use a specific Java Runtime Environment install?

If you mean when you are not the person writing the web page, then you could disable the add ons you do not wish to use with the Manage Add-Ons IE Options screen added in Win XP SP2

How do I add an element to array in reducer of React native redux?

I have a sample

import * as types from '../../helpers/ActionTypes';

var initialState = {
  changedValues: {}
};
const quickEdit = (state = initialState, action) => {

  switch (action.type) {

    case types.PRODUCT_QUICKEDIT:
      {
        const item = action.item;
        const changedValues = {
          ...state.changedValues,
          [item.id]: item,
        };

        return {
          ...state,
          loading: true,
          changedValues: changedValues,
        };
      }
    default:
      {
        return state;
      }
  }
};

export default quickEdit;

Difference between timestamps with/without time zone in PostgreSQL

Here is an example that should help. If you have a timestamp with a timezone, you can convert that timestamp into any other timezone. If you haven't got a base timezone it won't be converted correctly.

SELECT now(),
   now()::timestamp,
   now() AT TIME ZONE 'CST',
   now()::timestamp AT TIME ZONE 'CST'

Output:

-[ RECORD 1 ]---------------------------
now      | 2018-09-15 17:01:36.399357+03
now      | 2018-09-15 17:01:36.399357
timezone | 2018-09-15 08:01:36.399357
timezone | 2018-09-16 02:01:36.399357+03

Image inside div has extra space below the image

I used line-height:0 and it works fine for me.

Get value of input field inside an iframe

<iframe id="upload_target" name="upload_target">
    <textarea rows="20" cols="100" name="result" id="result" ></textarea>
    <input type="text" id="txt1" />
</iframe>

You can Get value by JQuery

$(document).ready(function(){
  alert($('#upload_target').contents().find('#result').html());
  alert($('#upload_target').contents().find('#txt1').val());
});

work on only same domain link

Seaborn plots not showing up

My advice is just to give a

plt.figure() and give some sns plot. For example

sns.distplot(data).

Though it will look it doesnt show any plot, When you maximise the figure, you will be able to see the plot.

How to get multiple selected values of select box in php?

I fix my problem with javascript + HTML. First i check selected options and save its in a hidden field of my form:

for(i=0; i < form.select.options.length; i++)
   if (form.select.options[i].selected)
    form.hidden.value += form.select.options[i].value;

Next, i get by post that field and get all the string ;-) I hope it'll be work for somebody more. Thanks to all.

What is the difference between require_relative and require in Ruby?

From Ruby API:

require_relative complements the builtin method require by allowing you to load a file that is relative to the file containing the require_relative statement.

When you use require to load a file, you are usually accessing functionality that has been properly installed, and made accessible, in your system. require does not offer a good solution for loading files within the project’s code. This may be useful during a development phase, for accessing test data, or even for accessing files that are "locked" away inside a project, not intended for outside use.

For example, if you have unit test classes in the "test" directory, and data for them under the test "test/data" directory, then you might use a line like this in a test case:

require_relative "data/customer_data_1" 

Since neither "test" nor "test/data" are likely to be in Ruby’s library path (and for good reason), a normal require won’t find them. require_relative is a good solution for this particular problem.

You may include or omit the extension (.rb or .so) of the file you are loading.

path must respond to to_str.

You can find the documentation at http://extensions.rubyforge.org/rdoc/classes/Kernel.html

Alternative for frames in html5 using iframes

While I agree with everyone else, if you are dead set on using frames anyway, you can just do index.html in XHTML and then do the contents of the frames in HTML5.

bash: pip: command not found

CentOS 7 users can just use:

yum install python-pip

Also recommend using virtualenv if you're using pip. It can be added in the same way:

yum install python-virtualenv

How to read and write to a text file in C++?

Look at this tutorial or this one, they are both pretty simple. If you are interested in an alternative this is how you do file I/O in C.

Some things to keep in mind, use single quotes ' when dealing with single characters, and double " for strings. Also it is a bad habit to use global variables when not necessary.

Have fun!

html/css buttons that scroll down to different div sections on a webpage

For something really basic use this:

<a href="#middle">Go To Middle</a>

Or for something simple in javascript check out this jQuery plugin ScrollTo. Quite useful for scrolling smoothly.

Angular is automatically adding 'ng-invalid' class on 'required' fields

the accepted answer is correct.. for mobile you can also use this (ng-touched rather ng-dirty)

input.ng-invalid.ng-touched{
  border-bottom: 1px solid #e74c3c !important; 
}

JSF(Primefaces) ajax update of several elements by ID's

If the to-be-updated component is not inside the same NamingContainer component (ui:repeat, h:form, h:dataTable, etc), then you need to specify the "absolute" client ID. Prefix with : (the default NamingContainer separator character) to start from root.

<p:ajax process="@this" update="count :subTotal"/>

To be sure, check the client ID of the subTotal component in the generated HTML for the actual value. If it's inside for example a h:form as well, then it's prefixed with its client ID as well and you would need to fix it accordingly.

<p:ajax process="@this" update="count :formId:subTotal"/>

Space separation of IDs is more recommended as <f:ajax> doesn't support comma separation and starters would otherwise get confused.

How to generate random positive and negative numbers in Java

([my double-compatible primitive type here])(Math.random() * [my max value here] * (Math.random() > 0.5 ? 1 : -1))

example:

// need a random number between -500 and +500
long myRandomLong = (long)(Math.random() * 500 * (Math.random() > 0.5 ? 1 : -1));

How to print register values in GDB?

info registers shows all the registers; info registers eax shows just the register eax. The command can be abbreviated as i r

Angular 2 Checkbox Two Way Data Binding

I prefer something more explicit:

component.html

<input #saveUserNameCheckBox
    id="saveUserNameCheckBox" 
    type="checkbox" 
    [checked]="saveUsername" 
    (change)="onSaveUsernameChanged(saveUserNameCheckBox.checked)" />

component.ts

public saveUsername:boolean;

public onSaveUsernameChanged(value:boolean){
    this.saveUsername = value;
}

Sending emails through SMTP with PHPMailer

SMTP -> FROM SERVER:
SMTP -> FROM SERVER:
SMTP -> ERROR: EHLO not accepted from server:

that's typical of trying to connect to a SSL service with a client that's not using SSL

SMTP Error: Could not authenticate.

no suprise there having failed to start an SMTP conversation authentigation is not an option,.

phpmailer doesn't do implicit SSL (aka TLS on connect, SMTPS) Short of rewriting smtp.class.php to include support for it there it no way to do what you ask.

Use port 587 with explicit SSL (aka TLS, STARTTLS) instead.

Error "library not found for" after putting application in AdMob

If error is like following

ld: library not found for -lpods

I found that a file "libPods.a" which is in red colour(like missing files) was created somehow in the Framework group of the project. I just simply removed that file and everything got fine.

EDIT: Another Solution

Another Solution that I have already answered in the similar question is in this link

HTML / CSS How to add image icon to input type="button"?

you can try this trick!

1st) do this:

<label for="img">
   <input type="submit" name="submit" id="img" value="img-btn">
   <img src="yourimage.jpg" id="img">
</label>

2nd) style it!

<style type="text/css">
   img:hover {
       cursor: pointer;
   }
   input[type=submit] {
       display: none;
   }
</style>

It is not clean but it will do the job!

How to use Apple's new .p8 certificate for APNs in firebase console

You can create the .p8 file for it in https://developer.apple.com/account/

Then go to Certificates, Identifiers & Profiles > Keys > add

apple_key

Select Apple Push Notification service (APNs), put a Key Name (whatever).

Then click on "continue", after "register" and you get it and you can download it.

Save file/open file dialog box, using Swing & Netbeans GUI editor

saving in any format is very much possible. Check following- http://docs.oracle.com/javase/tutorial/uiswing/components/filechooser.html

2ndly , What exactly you are expecting the save dialog to work , it works like that, Opening a doc file is very much possible- http://srikanthtechnologies.com/blog/openworddoc.html

How to run .jar file by double click on Windows 7 64-bit?

You may also run it from the Command Prompt (cmd):

java.exe -jar file.jar

Maven: add a dependency to a jar by relative path

Using the system scope. ${basedir} is the directory of your pom.

<dependency>
    <artifactId>..</artifactId>
    <groupId>..</groupId>
    <scope>system</scope>
    <systemPath>${basedir}/lib/dependency.jar</systemPath>
</dependency>

However it is advisable that you install your jar in the repository, and not commit it to the SCM - after all that's what maven tries to eliminate.

How to Convert an int to a String?

You have two options:

1) Using String.valueOf() method:

int sdRate=5;
text_Rate.setText(String.valueOf(sdRate));  //faster!, recommended! :)

2) adding an empty string:

int sdRate=5;
text_Rate.setText("" + sdRate)); 

Casting is not an option, will throw a ClassCastException

int sdRate=5;
text_Rate.setText(String.valueOf((String)sdRate)); //EXCEPTION!

sql: check if entry in table A exists in table B

If you are set on using EXISTS you can use the below in SQL Server:

SELECT * FROM TableB as b
WHERE NOT EXISTS
(
   SELECT * FROM TableA as a
   WHERE b.id = a.id
)

Bootstrap - How to add a logo to navbar class?

For those using bootstrap 4 beta you can add max-width on your navbar link to have control on the size of your logo with img-fluid class on the image element.

 <a class="navbar-brand" href="#" style="max-width: 30%;">
    <img src="images/logo.png" class="img-fluid">
 </a>

Enabling error display in PHP via htaccess only

php_flag display_errors on

To turn the actual display of errors on.

To set the types of errors you are displaying, you will need to use:

php_value error_reporting <integer>

Combined with the integer values from this page: http://php.net/manual/en/errorfunc.constants.php

Note if you use -1 for your integer, it will show all errors, and be future proof when they add in new types of errors.

How do I get the file name from a String containing the Absolute file path?

Alternative using Path (Java 7+):

Path p = Paths.get("C:\\Hello\\AnotherFolder\\The File Name.PDF");
String file = p.getFileName().toString();

Note that splitting the string on \\ is platform dependent as the file separator might vary. Path#getName takes care of that issue for you.

#1273 - Unknown collation: 'utf8mb4_unicode_ci' cPanel

If you are using PHP7, then you would need a PHP script like this one in order to migrate your collation:

<!DOCTYPE html>
<html>
<head>
  <title>DB-Convert</title>
  <style>
    body { font-family:"Courier New", Courier, monospace; }
  </style>
</head>
<body>

<h1>Convert your Database to utf8_general_ci!</h1>

<form action="db-convert.php" method="post">
  dbname: <input type="text" name="dbname"><br>
  dbuser: <input type="text" name="dbuser"><br>
  dbpass: <input type="text" name="dbpassword"><br>
  <input type="submit">
</form>

</body>
</html>
<?php
if ($_POST) {
  $dbname = $_POST['dbname'];
  $dbuser = $_POST['dbuser'];
  $dbpassword = $_POST['dbpassword'];

  $mysqli = new mysqli('db',$dbuser,$dbpassword);
  if ($mysqli -> connect_errno) {
    echo "Failed to connect to MySQL: " . $mysqli -> connect_error;
    exit();
  }
  $mysqli -> select_db($dbname);
  $result= $mysqli->query('show tables');
  while($tables = $result->fetch_array) {
          foreach ($tables as $key => $value) {
           $mysqli->query("ALTER TABLE $value CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci");
     }}
  echo "<script>alert('The collation of your database has been successfully changed!');</script>";
}

?>

Oracle query to fetch column names

The only way that I was able to get the column names was using the following query:

select COLUMN_NAME
FROM all_tab_columns atc
WHERE table_name like 'USERS'

Difference between Select Unique and Select Distinct

SELECT UNIQUE is old syntax supported by Oracle's flavor of SQL. It is synonymous with SELECT DISTINCT.

Use SELECT DISTINCT because this is standard SQL, and SELECT UNIQUE is non-standard, and in database brands other than Oracle, SELECT UNIQUE may not be recognized at all.

extract the date part from DateTime in C#

When comparing only the date of the datatimes, use the Date property. So this should work fine for you

datetime1.Date == datetime2.Date

Pod install is staying on "Setting up CocoaPods Master repo"

This happens only once.

  • Master repo has +-1GB (November 2016).

  • To track the progress you can use activity monitor app and look for git-remote-https.

  • Next time it (pod setup or pod repo update) will only fast update all spec-repos in ~/.cocoapods/repos.

How to convert/parse from String to char in java?

import java.io.*;
class ss1 
{
    public static void main(String args[]) 
    {
        String a = new String("sample");
        System.out.println("Result: ");
        for(int i=0;i<a.length();i++)
        {
            System.out.println(a.charAt(i));
        }
    }
}

How to select data of a table from another database in SQL Server?

Using Microsoft SQL Server Management Studio you can create Linked Server. First make connection to current (local) server, then go to Server Objects > Linked Servers > context menu > New Linked Server. In window New Linked Server you have to specify desired server name for remote server, real server name or IP address (Data Source) and credentials (Security page).

And further you can select data from linked server:

select * from [linked_server_name].[database].[schema].[table]

JSON.parse unexpected token s

You're asking it to parse the JSON text something (not "something"). That's invalid JSON, strings must be in double quotes.

If you want an equivalent to your first example:

var s = '"something"';
var result = JSON.parse(s);

How to get all key in JSON object (javascript)

I use Object.keys which is built into JavaScript Object, it will return an array of keys from given object MDN Reference

var obj = {name: "Jeeva", age: "22", gender: "Male"}
console.log(Object.keys(obj))

Making HTML page zoom by default

A better solution is not to make your page dependable on zoom settings. If you set limits like the one you are proposing, you are limiting accessibility. If someone cannot read your text well, they just won't be able to change that. I would use proper CSS to make it look nice in any zoom.

If your really insist, take a look at this question on how to detect zoom level using JavaScript (nightmare!): How to detect page zoom level in all modern browsers?

How can I count occurrences with groupBy?

List<String> list = new ArrayList<>();

list.add("Hello");
list.add("Hello");
list.add("World");

Map<String, List<String>> collect = list.stream()
                                        .collect(Collectors.groupingBy(o -> o));
collect.entrySet()
       .forEach(e -> System.out.println(e.getKey() + " - " + e.getValue().size()));

What does <? php echo ("<pre>"); ..... echo("</pre>"); ?> mean?

echo (""); is a php code, and <prev> tries to be HTML, but isn't.

As @pekka said, its probably supposed to be <pre>

JSON response parsing in Javascript to get key/value pair

There are two ways to access properties of objects:

var obj = {a: 'foo', b: 'bar'};

obj.a //foo
obj['b'] //bar

Or, if you need to dynamically do it:

var key = 'b';
obj[key] //bar

If you don't already have it as an object, you'll need to convert it.

For a more complex example, let's assume you have an array of objects that represent users:

var users = [{name: 'Corbin', age: 20, favoriteFoods: ['ice cream', 'pizza']},
             {name: 'John', age: 25, favoriteFoods: ['ice cream', 'skittle']}];

To access the age property of the second user, you would use users[1].age. To access the second "favoriteFood" of the first user, you'd use users[0].favoriteFoods[2].

Another example: obj[2].key[3]["some key"]

That would access the 3rd element of an array named 2. Then, it would access 'key' in that array, go to the third element of that, and then access the property name some key.


As Amadan noted, it might be worth also discussing how to loop over different structures.

To loop over an array, you can use a simple for loop:

var arr = ['a', 'b', 'c'],
    i;
for (i = 0; i < arr.length; ++i) {
    console.log(arr[i]);
}

To loop over an object is a bit more complicated. In the case that you're absolutely positive that the object is a plain object, you can use a plain for (x in obj) { } loop, but it's a lot safer to add in a hasOwnProperty check. This is necessary in situations where you cannot verify that the object does not have inherited properties. (It also future proofs the code a bit.)

var user = {name: 'Corbin', age: 20, location: 'USA'},
    key;

for (key in user) {
    if (user.hasOwnProperty(key)) {
        console.log(key + " = " + user[key]);
    }
}    

(Note that I've assumed whatever JS implementation you're using has console.log. If not, you could use alert or some kind of DOM manipulation instead.)

How to add data into ManyToMany field?

In case someone else ends up here struggling to customize admin form Many2Many saving behaviour, you can't call self.instance.my_m2m.add(obj) in your ModelForm.save override, as ModelForm.save later populates your m2m from self.cleaned_data['my_m2m'] which overwrites your changes. Instead call:

my_m2ms = list(self.cleaned_data['my_m2ms'])
my_m2ms.extend(my_custom_new_m2ms)
self.cleaned_data['my_m2ms'] = my_m2ms

(It is fine to convert the incoming QuerySet to a list - the ManyToManyField does that anyway.)

Laravel-5 how to populate select box from database with id value and name value

Controller

 $campaignStatus = Campaign::lists('status', 'id');

compact('campaignStatus') will result in [id=>status]; //example [1 => 'pending']

return view('management.campaign.index', compact('campaignStatus'));

View

{!! Form::select('status', $campaignStatus, array('class' => 'form-control')) !!}

How to get row number in dataframe in Pandas?

To get all indices that matches 'Smith'

>>> df[df['LastName'] == 'Smith'].index
Int64Index([1], dtype='int64')

or as a numpy array

>>> df[df['LastName'] == 'Smith'].index.to_numpy()  # .values on older versions
array([1])

or if there is only one and you want the integer, you can subset

>>> df[df['LastName'] == 'Smith'].index[0]
1

You could use the same boolean expressions with .loc, but it is not needed unless you also want to select a certain column, which is redundant when you only want the row number/index.

jquery's append not working with svg element?

This is working for me today with FF 57:

function () {
    // JQuery, today, doesn't play well with adding SVG elements - tricks required
    $(selector_to_node_in_svg_doc).parent().prepend($(this).clone().text("Your"));
    $(selector_to_node_in_svg_doc).text("New").attr("x", "340").text("New")
        .attr('stroke', 'blue').attr("style", "text-decoration: line-through");
}

Makes:

this SVG image as seen in Firefox 57

rbenv not changing ruby version

In my case changing the ~/.zshenv did not work. I had to make the changes inside ~/.zshrc.

I just added:

# Include rbenv for ZSH
export PATH="$HOME/.rbenv/bin:$PATH"
eval "$(rbenv init -)"

at the top of ~/.zshrc, restarted the shell and logged out.

Check if it worked:

?  ~ rbenv install 2.4.0
?  ~ rbenv global 2.4.0
?  ~ rbenv global
2.4.0
?  ~ ruby -v
ruby 2.4.0p0 (2016-12-24 revision 57164) [x86_64-darwin16]

Fill drop down list on selection of another drop down list

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Model:

namespace MvcApplicationrazor.Models
{
    public class CountryModel
    {
        public List<State> StateModel { get; set; }
        public SelectList FilteredCity { get; set; }
    }
    public class State
    {
        public int Id { get; set; }
        public string StateName { get; set; }
    }
    public class City
    {
        public int Id { get; set; }
        public int StateId { get; set; }
        public string CityName { get; set; }
    }
}   

Controller:

public ActionResult Index()
        {
            CountryModel objcountrymodel = new CountryModel();
            objcountrymodel.StateModel = new List<State>();
            objcountrymodel.StateModel = GetAllState();
            return View(objcountrymodel);
        }


        //Action result for ajax call
        [HttpPost]
        public ActionResult GetCityByStateId(int stateid)
        {
            List<City> objcity = new List<City>();
            objcity = GetAllCity().Where(m => m.StateId == stateid).ToList();
            SelectList obgcity = new SelectList(objcity, "Id", "CityName", 0);
            return Json(obgcity);
        }
        // Collection for state
        public List<State> GetAllState()
        {
            List<State> objstate = new List<State>();
            objstate.Add(new State { Id = 0, StateName = "Select State" });
            objstate.Add(new State { Id = 1, StateName = "State 1" });
            objstate.Add(new State { Id = 2, StateName = "State 2" });
            objstate.Add(new State { Id = 3, StateName = "State 3" });
            objstate.Add(new State { Id = 4, StateName = "State 4" });
            return objstate;
        }
        //collection for city
        public List<City> GetAllCity()
        {
            List<City> objcity = new List<City>();
            objcity.Add(new City { Id = 1, StateId = 1, CityName = "City1-1" });
            objcity.Add(new City { Id = 2, StateId = 2, CityName = "City2-1" });
            objcity.Add(new City { Id = 3, StateId = 4, CityName = "City4-1" });
            objcity.Add(new City { Id = 4, StateId = 1, CityName = "City1-2" });
            objcity.Add(new City { Id = 5, StateId = 1, CityName = "City1-3" });
            objcity.Add(new City { Id = 6, StateId = 4, CityName = "City4-2" });
            return objcity;
        }

View:

@model MvcApplicationrazor.Models.CountryModel
@{
    ViewBag.Title = "Index";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js"></script>
<script language="javascript" type="text/javascript">
    function GetCity(_stateId) {
        var procemessage = "<option value='0'> Please wait...</option>";
        $("#ddlcity").html(procemessage).show();
        var url = "/Test/GetCityByStateId/";

        $.ajax({
            url: url,
            data: { stateid: _stateId },
            cache: false,
            type: "POST",
            success: function (data) {
                var markup = "<option value='0'>Select City</option>";
                for (var x = 0; x < data.length; x++) {
                    markup += "<option value=" + data[x].Value + ">" + data[x].Text + "</option>";
                }
                $("#ddlcity").html(markup).show();
            },
            error: function (reponse) {
                alert("error : " + reponse);
            }
        });

    }
</script>
<h4>
 MVC Cascading Dropdown List Using Jquery</h4>
@using (Html.BeginForm())
{
    @Html.DropDownListFor(m => m.StateModel, new SelectList(Model.StateModel, "Id", "StateName"), new { @id = "ddlstate", @style = "width:200px;", @onchange = "javascript:GetCity(this.value);" })
    <br />
    <br />
    <select id="ddlcity" name="ddlcity" style="width: 200px">

    </select>

    <br /><br />
  }

NSPhotoLibraryUsageDescription key must be present in Info.plist to use camera roll

You need to paste these two in your info.plist, The only way that worked in iOS 11 for me.

    <key>NSPhotoLibraryUsageDescription</key>
    <string>This app requires access to the photo library.</string>

    <key>NSPhotoLibraryAddUsageDescription</key>
    <string>This app requires access to the photo library.</string>

Unable to locate an executable at "/usr/bin/java/bin/java" (-1)

For those using newer versions of java: jhat has been removed since Java 9. Source: https://www.infoq.com/news/2015/12/OpenJDK-9-removal-of-HPROF-jhat/

That same article recommends using Java VisualVM instead.

python - checking odd/even numbers and changing outputs on number size

there are a lot of ways to check if an int value is odd or even. I'll show you the two main ways:

number = 5

def best_way(number):
    if number%2==0:
        print "even"
    else:
        print "odd"

def binary_way(number):
    if str(bin(number))[len(bin(number))-1]=='0':
        print "even"
    else:
        print "odd"
best_way(number)
binary_way(number)

hope it helps

I am not able launch JNLP applications using "Java Web Start"?

In my case, Netbeans automatically creates a .jnlp file that doesn't work and my problem was due to an accidental overwriting of the launch.jnlp file on the server (by the inadequate and incorrect version from Netbeans). This caused a mismatch between the local .jnlp file and the remote .jnlp file, resulting in Java Web Start just quitting after "Verifying application."

So no one else has to waste an hour finding a bug that should be communicated adequately (but isn't) by Java WS.

Using async/await for multiple tasks

I just want to add to all great answers above, that if you write a library it's a good practice to use ConfigureAwait(false) and get better performance, as said here.

So this snippet seems to be better:

 public static async Task DoWork() 
 {
     int[] ids = new[] { 1, 2, 3, 4, 5 };
     await Task.WhenAll(ids.Select(i => DoSomething(1, i))).ConfigureAwait(false);
 }

A full fiddle link here.

How do I get bit-by-bit data from an integer value in C?

As requested, I decided to extend my comment on forefinger's answer to a full-fledged answer. Although his answer is correct, it is needlessly complex. Furthermore all current answers use signed ints to represent the values. This is dangerous, as right-shifting of negative values is implementation-defined (i.e. not portable) and left-shifting can lead to undefined behavior (see this question).

By right-shifting the desired bit into the least significant bit position, masking can be done with 1. No need to compute a new mask value for each bit.

(n >> k) & 1

As a complete program, computing (and subsequently printing) an array of single bit values:

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char** argv)
{
    unsigned
        input = 0b0111u,
        n_bits = 4u,
        *bits = (unsigned*)malloc(sizeof(unsigned) * n_bits),
        bit = 0;

    for(bit = 0; bit < n_bits; ++bit)
        bits[bit] = (input >> bit) & 1;

    for(bit = n_bits; bit--;)
        printf("%u", bits[bit]);
    printf("\n");

    free(bits);
}

Assuming that you want to calculate all bits as in this case, and not a specific one, the loop can be further changed to

for(bit = 0; bit < n_bits; ++bit, input >>= 1)
    bits[bit] = input & 1;

This modifies input in place and thereby allows the use of a constant width, single-bit shift, which may be more efficient on some architectures.

How can we draw a vertical line in the webpage?

There are no vertical lines in html that you can use but you can fake one by absolutely positioning a div outside of your container with a top:0; and bottom:0; style.

Try this:

CSS

.vr {
    width:10px;
    background-color:#000;
    position:absolute;
    top:0;
    bottom:0;
    left:150px;
}

HTML

<div class="vr">&nbsp;</div>

Demo

CSS: background image on background color

The next syntax can be used as well.

background: <background-color> 
            url('../assets/icons/my-icon.svg')
            <background-position-x background-position-y>
            <background-repeat>;

It allows you combining background-color, background-image, background-position and background-repeat properties.

Example

background: #696969 url('../assets/icons/my-icon.svg') center center no-repeat;

Simple way to change the position of UIView?

I had the same problem. I made a simple UIView category that fixes that.

.h

#import <UIKit/UIKit.h>


@interface UIView (GCLibrary)

@property (nonatomic, assign) CGFloat height;
@property (nonatomic, assign) CGFloat width;
@property (nonatomic, assign) CGFloat x;
@property (nonatomic, assign) CGFloat y;

@end

.m

#import "UIView+GCLibrary.h"


@implementation UIView (GCLibrary)

- (CGFloat) height {
    return self.frame.size.height;
}

- (CGFloat) width {
    return self.frame.size.width;
}

- (CGFloat) x {
    return self.frame.origin.x;
}

- (CGFloat) y {
    return self.frame.origin.y;
}

- (CGFloat) centerY {
    return self.center.y;
}

- (CGFloat) centerX {
    return self.center.x;
}

- (void) setHeight:(CGFloat) newHeight {
    CGRect frame = self.frame;
    frame.size.height = newHeight;
    self.frame = frame;
}

- (void) setWidth:(CGFloat) newWidth {
    CGRect frame = self.frame;
    frame.size.width = newWidth;
    self.frame = frame;
}

- (void) setX:(CGFloat) newX {
    CGRect frame = self.frame;
    frame.origin.x = newX;
    self.frame = frame;
}

- (void) setY:(CGFloat) newY {
    CGRect frame = self.frame;
    frame.origin.y = newY;
    self.frame = frame;
}

@end

[Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified

  1. In reference to the error: [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified.

    That error means that the Data Source Name (DSN) you are specifying in your connection configuration is not being found in the windows registry.

    • It is important that your ODBC driver's executable and linking format (ELF) is the same as your application. In other words, you need a 32-bit driver for a 32-bit application or a 64-bit driver for a 64-bit application.

      If these do not match, it is possible to configure a DSN for a 32-bit driver and when you attempt to use that DSN in a 64-bit application, the DSN won't be found because the registry holds DSN information in different places depending on ELF (32-bit versus 64-bit).

      Be sure you are using the correct ODBC Administrator tool. On 32-bit and 64-bit Windows, the default ODBC Administrator tool is in c:\Windows\System32\odbcad32.exe. However, on a 64-bit Windows machine, the default is the 64-bit version. If you need to use the 32-bit ODBC Administrator tool on a 64-bit Windows system, you will need to run the one found here: C:\Windows\SysWOW64\odbcad32.exe

      Where I see this tripping people up is when a user uses the default 64-bit ODBC Administrator to configure a DSN; thinking it is for a 32-bit DSN. Then when the 32-bit application attempts to connect using that DSN, "Data source not found..." occurs.

    • It's also important to make sure the spelling of the DSN matches that of the configured DSN in the ODBC Administrator. One letter wrong is all it takes for a DSN to be mismatched.

      Here is an article that may provide some additional details

      It may not be the same product brand that you have, however; it is a generic problem that is encountered when using ODBC data source names.

  2. In reference to the OLE DB Provider portion of your question, it appears to be a similar type of problem where the application is not able to locate the configuration for the specified provider.

Adding values to a C# array

Just a different approach:

int runs = 0; 
bool batting = true; 
string scorecard;

while (batting = runs < 400)
    scorecard += "!" + runs++;

return scorecard.Split("!");

Git diff --name-only and copy that list

The following should work fine:

git diff -z --name-only commit1 commit2 | xargs -0 -IREPLACE rsync -aR REPLACE /home/changes/protected/

To explain further:

  • The -z to with git diff --name-only means to output the list of files separated with NUL bytes instead of newlines, just in case your filenames have unusual characters in them.

  • The -0 to xargs says to interpret standard input as a NUL-separated list of parameters.

  • The -IREPLACE is needed since by default xargs would append the parameters to the end of the rsync command. Instead, that says to put them where the later REPLACE is. (That's a nice tip from this Server Fault answer.)

  • The -a parameter to rsync means to preserve permissions, ownership, etc. if possible. The -R means to use the full relative path when creating the files in the destination.

Update: if you have an old version of xargs, you'll need to use the -i option instead of -I. (The former is deprecated in later versions of findutils.)

Ajax success function

The answer given above can't solve my problem.So I change async into false to get the alert message.

jQuery.ajax({
            type:"post",
            dataType:"json",
            async: false,
            url: myAjax.ajaxurl,
            data: {action: 'submit_data', info: info},
            success: function(data) {
                alert("Data was succesfully captured");
            },
        });

How do you develop Java Servlets using Eclipse?

Alternatively you can use Jetty which is (now) part of the Eclipe Platform (the Help system is running Jetty). Besides Jetty is used by Android, Windows Mobile..

To get started check the Eclipse Wiki or if you prefer a Video And check out this related Post!

Is there a way to compile node.js source files?

Node.js runs on top of the V8 Javascript engine, which itself optimizes performance by compiling javascript code into native code... so no reason really for compiling then, is there?

https://developers.google.com/v8/design#mach_code

Capture iframe load complete event

Step 1: Add iframe in template.

<iframe id="uvIFrame" src="www.google.com"></iframe>

Step 2: Add load listener in Controller.

document.querySelector('iframe#uvIFrame').addEventListener('load', function () {
  $scope.loading = false;
  $scope.$apply();
});

Maximum number of rows in an MS Access database engine table?

It's been some years since I last worked with Access but larger database files always used to have more problems and be more prone to corruption than smaller files.

Unless the database file is only being accessed by one person or stored on a robust network you may find this is a problem before the 2GB database size limit is reached.

changing permission for files and folder recursively using shell command in mac

You can just use the -R (recursive) flag.

chmod -R 777 /Users/Test/Desktop/PATH

How can I force a hard reload in Chrome for Android

I'm using window.location.reload(true) according to MDN (and this similar question) it forces page to reload from server.

You can execute this code in the browser by typing javascript:location.reload(true) in the address bar.

Drop all tables whose names begin with a certain string

SELECT 'if object_id(''' + TABLE_NAME + ''') is not null begin drop table "' + TABLE_NAME + '" end;' 
FROM INFORMATION_SCHEMA.TABLES 
WHERE TABLE_NAME LIKE '[prefix]%'

Remove all special characters with RegExp

why dont you do something like:

re = /^[a-z0-9 ]$/i;
var isValid = re.test(yourInput);

to check if your input contain any special char

How to get < span > value?

Pure javascript would be like this

var children = document.getElementById('test').children;

If you are using jQuery it would be like this

$("#test").children()

How do you get the width and height of a multi-dimensional array?

Use GetLength(), rather than Length.

int rowsOrHeight = ary.GetLength(0);
int colsOrWidth = ary.GetLength(1);

Remove numbers from string sql server

Remove everything after first digit (was adequate for my use case): LEFT(field,PATINDEX('%[0-9]%',field+'0')-1)

Remove trailing digits: LEFT(field,len(field)+1-PATINDEX('%[^0-9]%',reverse('0'+field))

How is TeamViewer so fast?

My random guess is: TV uses x264 codec which has a commercial license (otherwise TeamViewer would have to release their source code). At some point (more than 5 years ago), I recall main developer of x264 wrote an article about improvements he made for low delay encoding (if you delay by a few frames encoders can compress better), plus he mentioned some other improvements that were relevant for TeamViewer-like use. In that post he mentioned playing quake over video stream with no noticeable issues. Back then I was kind of sure who was the sponsor of these improvements, as TeamViewer was pretty much the only option at that time. x264 is an open source implementation of H264 video codec, and it's insanely good implementation, it's the best one. At the same time it's extremely well optimized. Most likely due to extremely good implementation of x264 you get much better results with TV at lower CPU load. AnyDesk and Chrome Remote Desk use libvpx, which isn't as good as x264 (optimization and video quality wise).

However, I don't think TeamView can beat microsoft's RDP. To me it's the best, however it works between windows PCs or from Mac to Windows only. TV works even from mobiles.

Update: article was written in January 2010, so that work was done roughly 10 years ago. Also, I made a mistake: he played call of duty, not quake. When you posted your question, if my guess is correct, TeamViewer had been using that work for 3 years. Read that blog post from web archive: x264: the best low-latency video streaming platform in the world. When I read the article back in 2010, I was sure that the "startup–which has requested not to be named" that the author mentions was TeamViewer.

Vertically align text within a div

I know it’s totally stupid and you normally really shouldn’t use tables when not creating tables, but:

Table cells can align multiple lines of text vertically centered and even do this by default. So a solution which works quite fine could be something like this:

HTML:

<div class="box">
  <table class="textalignmiddle">
    <tr>
      <td>lorem ipsum ...</td>
    </tr>
  </table>
</div>

CSS (make the table item always fit to the box div):

.box {
  /* For example */
  height: 300px;
}

.textalignmiddle {
  width: 100%;
  height: 100%;
}

See here: http://www.cssdesk.com/LzpeV

not:first-child selector

One of the versions you posted actually works for all modern browsers (where CSS selectors level 3 are supported):

div ul:not(:first-child) {
    background-color: #900;
}

If you need to support legacy browsers, or if you are hindered by the :not selector's limitation (it only accepts a simple selector as an argument) then you can use another technique:

Define a rule that has greater scope than what you intend and then "revoke" it conditionally, limiting its scope to what you do intend:

div ul {
    background-color: #900;  /* applies to every ul */
}

div ul:first-child {
    background-color: transparent; /* limits the scope of the previous rule */
}

When limiting the scope use the default value for each CSS attribute that you are setting.

How to add an item to an ArrayList in Kotlin?

If you have a MUTABLE collection:

val list = mutableListOf(1, 2, 3)
list += 4

If you have an IMMUTABLE collection:

var list = listOf(1, 2, 3)
list += 4

note that I use val for the mutable list to emphasize that the object is always the same, but its content changes.

In case of the immutable list, you have to make it var. A new object is created by the += operator with the additional value.

How to see the changes in a Git commit?

It is also possible to review changes between two commits for a specific file.

git diff <commit_Id_1> <commit_Id_2> some_dir/file.txt

How to hide app title in android?

use

<activity android:name=".ActivityName" 
          android:theme="@android:style/Theme.NoTitleBar">

How to efficiently use try...catch blocks in PHP

There is no any problem to write multiple lines of execution withing a single try catch block like below

try{
install_engine();
install_break();
}
catch(Exception $e){
show_exception($e->getMessage());
}

The moment any execption occure either in install_engine or install_break function the control will be passed to catch function. One more recommendation is to eat your exception properly. Which means instead of writing die('Message') it is always advisable to have exception process properly. You may think of using die() function in error handling but not in exception handling.

When you should use multiple try catch block You can think about multiple try catch block if you want the different code block exception to display different type of exception or you are trying to throw any exception from your catch block like below:

try{
    install_engine();
    install_break();
    }
    catch(Exception $e){
    show_exception($e->getMessage());
    }
try{
install_body();
paint_body();
install_interiour();
}
catch(Exception $e){
throw new exception('Body Makeover faield')
}

How to update Git clone

If you want to fetch + merge, run

git pull

if you want simply to fetch :

git fetch

Send multiple checkbox data to PHP via jQuery ajax()

You may also try this,

var arr = $('input[name="myCheckboxes[]"]').map(function(){
  return $(this).val();
}).get();

console.log(arr);

Invoking Java main method with parameters from Eclipse

AFAIK there isn't a built-in mechanism in Eclipse for this.

The closest you can get is to create a wrapper that prompts you for these values and invokes the (hardcoded) main. You then get you execution history as long as you don't clear terminated processes. Two variations on this are either to use JUNit, or to use injection or parameter so that your wrapper always connects to the correct class for its main.

Evaluating a mathematical expression in a string

eval is evil

eval("__import__('os').remove('important file')") # arbitrary commands
eval("9**9**9**9**9**9**9**9", {'__builtins__': None}) # CPU, memory

Note: even if you use set __builtins__ to None it still might be possible to break out using introspection:

eval('(1).__class__.__bases__[0].__subclasses__()', {'__builtins__': None})

Evaluate arithmetic expression using ast

import ast
import operator as op

# supported operators
operators = {ast.Add: op.add, ast.Sub: op.sub, ast.Mult: op.mul,
             ast.Div: op.truediv, ast.Pow: op.pow, ast.BitXor: op.xor,
             ast.USub: op.neg}

def eval_expr(expr):
    """
    >>> eval_expr('2^6')
    4
    >>> eval_expr('2**6')
    64
    >>> eval_expr('1 + 2*3**(4^5) / (6 + -7)')
    -5.0
    """
    return eval_(ast.parse(expr, mode='eval').body)

def eval_(node):
    if isinstance(node, ast.Num): # <number>
        return node.n
    elif isinstance(node, ast.BinOp): # <left> <operator> <right>
        return operators[type(node.op)](eval_(node.left), eval_(node.right))
    elif isinstance(node, ast.UnaryOp): # <operator> <operand> e.g., -1
        return operators[type(node.op)](eval_(node.operand))
    else:
        raise TypeError(node)

You can easily limit allowed range for each operation or any intermediate result, e.g., to limit input arguments for a**b:

def power(a, b):
    if any(abs(n) > 100 for n in [a, b]):
        raise ValueError((a,b))
    return op.pow(a, b)
operators[ast.Pow] = power

Or to limit magnitude of intermediate results:

import functools

def limit(max_=None):
    """Return decorator that limits allowed returned values."""
    def decorator(func):
        @functools.wraps(func)
        def wrapper(*args, **kwargs):
            ret = func(*args, **kwargs)
            try:
                mag = abs(ret)
            except TypeError:
                pass # not applicable
            else:
                if mag > max_:
                    raise ValueError(ret)
            return ret
        return wrapper
    return decorator

eval_ = limit(max_=10**100)(eval_)

Example

>>> evil = "__import__('os').remove('important file')"
>>> eval_expr(evil) #doctest:+IGNORE_EXCEPTION_DETAIL
Traceback (most recent call last):
...
TypeError:
>>> eval_expr("9**9")
387420489
>>> eval_expr("9**9**9**9**9**9**9**9") #doctest:+IGNORE_EXCEPTION_DETAIL
Traceback (most recent call last):
...
ValueError:

How to check if an integer is within a range of numbers in PHP?

I created a function to check if times in an array overlap somehow:

    /**
     * Function to check if there are overlapping times in an array of \DateTime objects.
     *
     * @param $ranges
     *
     * @return \DateTime[]|bool
     */
    public function timesOverlap($ranges) {
        foreach ($ranges as $k1 => $t1) {
            foreach ($ranges as $k2 => $t2) {
                if ($k1 != $k2) {
                    /* @var \DateTime[] $t1 */
                    /* @var \DateTime[] $t2 */
                    $a = $t1[0]->getTimestamp();
                    $b = $t1[1]->getTimestamp();
                    $c = $t2[0]->getTimestamp();
                    $d = $t2[1]->getTimestamp();

                    if (($c >= $a && $c <= $b) || $d >= $a && $d <= $b) {
                        return true;
                    }
                }
            }
        }

        return false;
    }

CSS 3 slide-in from left transition

Use CSS3 2D transform to avoid performance issues (mobile)

A common pitfall is to animate left/top/right/bottom properties instead of using to achieve the same effect. For a variety of reasons, the semantics of transforms make them easier to offload, but left/top/right/bottom are much more difficult.

Source: Mozilla Developer Network (MDN)


Demo:

_x000D_
_x000D_
var $slider = document.getElementById('slider');
var $toggle = document.getElementById('toggle');

$toggle.addEventListener('click', function() {
    var isOpen = $slider.classList.contains('slide-in');

    $slider.setAttribute('class', isOpen ? 'slide-out' : 'slide-in');
});
_x000D_
#slider {
    position: absolute;
    width: 100px;
    height: 100px;
    background: blue;
    transform: translateX(-100%);
    -webkit-transform: translateX(-100%);
}

.slide-in {
    animation: slide-in 0.5s forwards;
    -webkit-animation: slide-in 0.5s forwards;
}

.slide-out {
    animation: slide-out 0.5s forwards;
    -webkit-animation: slide-out 0.5s forwards;
}
    
@keyframes slide-in {
    100% { transform: translateX(0%); }
}

@-webkit-keyframes slide-in {
    100% { -webkit-transform: translateX(0%); }
}
    
@keyframes slide-out {
    0% { transform: translateX(0%); }
    100% { transform: translateX(-100%); }
}

@-webkit-keyframes slide-out {
    0% { -webkit-transform: translateX(0%); }
    100% { -webkit-transform: translateX(-100%); }
}
_x000D_
<div id="slider" class="slide-in">
    <ul>
        <li>Lorem</li>
        <li>Ipsum</li>
        <li>Dolor</li>
    </ul>
</div>

<button id="toggle" style="position:absolute; top: 120px;">Toggle</button>
_x000D_
_x000D_
_x000D_

How to do associative array/hashing in JavaScript

Unless you have a specific reason not to, just use a normal object. Object properties in JavaScript can be referenced using hashtable-style syntax:

var hashtable = {};
hashtable.foo = "bar";
hashtable['bar'] = "foo";

Both foo and bar elements can now then be referenced as:

hashtable['foo'];
hashtable['bar'];

// Or
hashtable.foo;
hashtable.bar;

Of course this does mean your keys have to be strings. If they're not strings they are converted internally to strings, so it may still work. Your mileage may vary.

Python idiom to return first item or None

my_list[0] if len(my_list) else None

How to call a vue.js function on page load

You can call this function in beforeMount section of a Vue component: like following:

 ....
 methods:{
     getUnits: function() {...}
 },
 beforeMount(){
    this.getUnits()
 },
 ......

Working fiddle: https://jsfiddle.net/q83bnLrx/1/

There are different lifecycle hooks Vue provide:

I have listed few are :

  1. beforeCreate: Called synchronously after the instance has just been initialized, before data observation and event/watcher setup.
  2. created: Called synchronously after the instance is created. At this stage, the instance has finished processing the options which means the following have been set up: data observation, computed properties, methods, watch/event callbacks. However, the mounting phase has not been started, and the $el property will not be available yet.
  3. beforeMount: Called right before the mounting begins: the render function is about to be called for the first time.
  4. mounted: Called after the instance has just been mounted where el is replaced by the newly created vm.$el.
  5. beforeUpdate: Called when the data changes, before the virtual DOM is re-rendered and patched.
  6. updated: Called after a data change causes the virtual DOM to be re-rendered and patched.

You can have a look at complete list here.

You can choose which hook is most suitable to you and hook it to call you function like the sample code provided above.

Web colors in an Android color xml resource file

<!-- Black Transparent -->
<color name="transparent_black_hex_1">#11000000</color>
<color name="transparent_black_hex_2">#22000000</color>
<color name="transparent_black_hex_3">#33000000</color>
<color name="transparent_black_hex_4">#44000000</color>
<color name="transparent_black_hex_5">#55000000</color>
<color name="transparent_black_hex_6">#66000000</color>
<color name="transparent_black_hex_7">#77000000</color>
<color name="transparent_black_hex_8">#88000000</color>
<color name="transparent_black_hex_9">#99000000</color>
<color name="transparent_black_hex_10">#aa000000</color>
<color name="transparent_black_hex_11">#bb000000</color>
<color name="transparent_black_hex_12">#cc000000</color>
<color name="transparent_black_hex_13">#dd000000</color>
<color name="transparent_black_hex_14">#ee000000</color>
<color name="transparent_black_hex_15">#ff000000</color>

<color name="transparent_black_percent_5">#0D000000</color>
<color name="transparent_black_percent_10">#1A000000</color>
<color name="transparent_black_percent_15">#26000000</color>
<color name="transparent_black_percent_20">#33000000</color>
<color name="transparent_black_percent_25">#40000000</color>
<color name="transparent_black_percent_30">#4D000000</color>
<color name="transparent_black_percent_35">#59000000</color>
<color name="transparent_black_percent_40">#66000000</color>
<color name="transparent_black_percent_45">#73000000</color>
<color name="transparent_black_percent_50">#80000000</color>
<color name="transparent_black_percent_55">#8C000000</color>
<color name="transparent_black_percent_60">#99000000</color>
<color name="transparent_black_percent_65">#A6000000</color>
<color name="transparent_black_percent_70">#B3000000</color>
<color name="transparent_black_percent_75">#BF000000</color>
<color name="transparent_black_percent_80">#CC000000</color>
<color name="transparent_black_percent_85">#D9000000</color>
<color name="transparent_black_percent_90">#E6000000</color>
<color name="transparent_black_percent_95">#F2000000</color>

<!-- White Transparent -->
<color name="transparent_white_hex_1">#11ffffff</color>
<color name="transparent_white_hex_2">#22ffffff</color>
<color name="transparent_white_hex_3">#33ffffff</color>
<color name="transparent_white_hex_4">#44ffffff</color>
<color name="transparent_white_hex_5">#55ffffff</color>
<color name="transparent_white_hex_6">#66ffffff</color>
<color name="transparent_white_hex_7">#77ffffff</color>
<color name="transparent_white_hex_8">#88ffffff</color>
<color name="transparent_white_hex_9">#99ffffff</color>
<color name="transparent_white_hex_10">#aaffffff</color>
<color name="transparent_white_hex_11">#bbffffff</color>
<color name="transparent_white_hex_12">#ccffffff</color>
<color name="transparent_white_hex_13">#ddffffff</color>
<color name="transparent_white_hex_14">#eeffffff</color>
<color name="transparent_white_hex_15">#ffffffff</color>

<color name="transparent_white_percent_5">#0Dffffff</color>
<color name="transparent_white_percent_10">#1Affffff</color>
<color name="transparent_white_percent_15">#26ffffff</color>
<color name="transparent_white_percent_20">#33ffffff</color>
<color name="transparent_white_percent_25">#40ffffff</color>
<color name="transparent_white_percent_30">#4Dffffff</color>
<color name="transparent_white_percent_35">#59ffffff</color>
<color name="transparent_white_percent_40">#66ffffff</color>
<color name="transparent_white_percent_45">#73ffffff</color>
<color name="transparent_white_percent_50">#80ffffff</color>
<color name="transparent_white_percent_55">#8Cffffff</color>
<color name="transparent_white_percent_60">#99ffffff</color>
<color name="transparent_white_percent_65">#A6ffffff</color>
<color name="transparent_white_percent_70">#B3ffffff</color>
<color name="transparent_white_percent_75">#BFffffff</color>
<color name="transparent_white_percent_80">#CCffffff</color>
<color name="transparent_white_percent_85">#D9ffffff</color>
<color name="transparent_white_percent_90">#E6ffffff</color>
<color name="transparent_white_percent_95">#F2ffffff</color>

How can I get the order ID in WooCommerce?

it worked. Just modified it

global $woocommerce, $post;

$order = new WC_Order($post->ID);

//to escape # from order id 

$order_id = trim(str_replace('#', '', $order->get_order_number()));

Check if string contains only letters in javascript

The fastest way is to check if there is a non letter:

if (!/[^a-zA-Z]/.test(word))

Why doesn't calling a Python string method do anything unless you assign its output?

Example for String Methods

Given a list of filenames, we want to rename all the files with extension hpp to the extension h. To do this, we would like to generate a new list called newfilenames, consisting of the new filenames. Fill in the blanks in the code using any of the methods you’ve learned thus far, like a for loop or a list comprehension.

filenames = ["program.c", "stdio.hpp", "sample.hpp", "a.out", "math.hpp", "hpp.out"]
# Generate newfilenames as a list containing the new filenames
# using as many lines of code as your chosen method requires.
newfilenames = []
for i in filenames:
    if i.endswith(".hpp"):
        x = i.replace("hpp", "h")
        newfilenames.append(x)
    else:
        newfilenames.append(i)


print(newfilenames)
# Should be ["program.c", "stdio.h", "sample.h", "a.out", "math.h", "hpp.out"]

How to use LINQ Distinct() with multiple fields

public List<ItemCustom2> GetBrandListByCat(int id)
    {

        var OBJ = (from a in db.Items
                   join b in db.Brands on a.BrandId equals b.Id into abc1
                   where (a.ItemCategoryId == id)
                   from b in abc1.DefaultIfEmpty()
                   select new
                   {
                       ItemCategoryId = a.ItemCategoryId,
                       Brand_Name = b.Name,
                       Brand_Id = b.Id,
                       Brand_Pic = b.Pic,

                   }).Distinct();


        List<ItemCustom2> ob = new List<ItemCustom2>();
        foreach (var item in OBJ)
        {
            ItemCustom2 abc = new ItemCustom2();
            abc.CategoryId = item.ItemCategoryId;
            abc.BrandId = item.Brand_Id;
            abc.BrandName = item.Brand_Name;
            abc.BrandPic = item.Brand_Pic;
            ob.Add(abc);
        }
        return ob;

    }

matplotlib: Group boxplots

Grouped boxplots, towards subtle academic publication styling... (source)

(Left) Python 2.7.12 Matplotlib v1.5.3. (Right) Python 3.7.3. Matplotlib v3.1.0.

grouped boxplot example png for Python 2.7.12 Matplotlib v1.5.3 grouped boxplot example png for Python 3.7.3 Matplotlib v3.1.0

Code:

import numpy as np
import matplotlib.pyplot as plt

# --- Your data, e.g. results per algorithm:
data1 = [5,5,4,3,3,5]
data2 = [6,6,4,6,8,5]
data3 = [7,8,4,5,8,2]
data4 = [6,9,3,6,8,4]

# --- Combining your data:
data_group1 = [data1, data2]
data_group2 = [data3, data4]

# --- Labels for your data:
labels_list = ['a','b']
xlocations  = range(len(data_group1))
width       = 0.3
symbol      = 'r+'
ymin        = 0
ymax        = 10

ax = plt.gca()
ax.set_ylim(ymin,ymax)
ax.set_xticklabels( labels_list, rotation=0 )
ax.grid(True, linestyle='dotted')
ax.set_axisbelow(True)
ax.set_xticks(xlocations)
plt.xlabel('X axis label')
plt.ylabel('Y axis label')
plt.title('title')

# --- Offset the positions per group:
positions_group1 = [x-(width+0.01) for x in xlocations]
positions_group2 = xlocations

plt.boxplot(data_group1, 
            sym=symbol,
            labels=['']*len(labels_list),
            positions=positions_group1, 
            widths=width, 
#           notch=False,  
#           vert=True, 
#           whis=1.5,
#           bootstrap=None, 
#           usermedians=None, 
#           conf_intervals=None,
#           patch_artist=False,
            )

plt.boxplot(data_group2, 
            labels=labels_list,
            sym=symbol,
            positions=positions_group2, 
            widths=width, 
#           notch=False,  
#           vert=True, 
#           whis=1.5,
#           bootstrap=None, 
#           usermedians=None, 
#           conf_intervals=None,
#           patch_artist=False,
            )

plt.savefig('boxplot_grouped.png')  
plt.savefig('boxplot_grouped.pdf')    # when publishing, use high quality PDFs
#plt.show()                   # uncomment to show the plot. 

python convert list to dictionary

If you are still thinking what the! You would not be alone, its actually not that complicated really, let me explain.

How to turn a list into a dictionary using built-in functions only

We want to turn the following list into a dictionary using the odd entries (counting from 1) as keys mapped to their consecutive even entries.

l = ["a", "b", "c", "d", "e"]

dict()

To create a dictionary we can use the built in dict function for Mapping Types as per the manual the following methods are supported.

dict(one=1, two=2)
dict({'one': 1, 'two': 2})
dict(zip(('one', 'two'), (1, 2)))
dict([['two', 2], ['one', 1]])

The last option suggests that we supply a list of lists with 2 values or (key, value) tuples, so we want to turn our sequential list into:

l = [["a", "b"], ["c", "d"], ["e",]]

We are also introduced to the zip function, one of the built-in functions which the manual explains:

returns a list of tuples, where the i-th tuple contains the i-th element from each of the arguments

In other words if we can turn our list into two lists a, c, e and b, d then zip will do the rest.

slice notation

Slicings which we see used with Strings and also further on in the List section which mainly uses the range or short slice notation but this is what the long slice notation looks like and what we can accomplish with step:

>>> l[::2]
['a', 'c', 'e']

>>> l[1::2]
['b', 'd']

>>> zip(['a', 'c', 'e'], ['b', 'd'])
[('a', 'b'), ('c', 'd')]

>>> dict(zip(l[::2], l[1::2]))
{'a': 'b', 'c': 'd'}

Even though this is the simplest way to understand the mechanics involved there is a downside because slices are new list objects each time, as can be seen with this cloning example:

>>> a = [1, 2, 3]
>>> b = a
>>> b
[1, 2, 3]

>>> b is a
True

>>> b = a[:]
>>> b
[1, 2, 3]

>>> b is a
False

Even though b looks like a they are two separate objects now and this is why we prefer to use the grouper recipe instead.

grouper recipe

Although the grouper is explained as part of the itertools module it works perfectly fine with the basic functions too.

Some serious voodoo right? =) But actually nothing more than a bit of syntax sugar for spice, the grouper recipe is accomplished by the following expression.

*[iter(l)]*2

Which more or less translates to two arguments of the same iterator wrapped in a list, if that makes any sense. Lets break it down to help shed some light.

zip for shortest

>>> l*2
['a', 'b', 'c', 'd', 'e', 'a', 'b', 'c', 'd', 'e']

>>> [l]*2
[['a', 'b', 'c', 'd', 'e'], ['a', 'b', 'c', 'd', 'e']]

>>> [iter(l)]*2
[<listiterator object at 0x100486450>, <listiterator object at 0x100486450>]

>>> zip([iter(l)]*2)
[(<listiterator object at 0x1004865d0>,),(<listiterator object at 0x1004865d0>,)]

>>> zip(*[iter(l)]*2)
[('a', 'b'), ('c', 'd')]

>>> dict(zip(*[iter(l)]*2))
{'a': 'b', 'c': 'd'}

As you can see the addresses for the two iterators remain the same so we are working with the same iterator which zip then first gets a key from and then a value and a key and a value every time stepping the same iterator to accomplish what we did with the slices much more productively.

You would accomplish very much the same with the following which carries a smaller What the? factor perhaps.

>>> it = iter(l)     
>>> dict(zip(it, it))
{'a': 'b', 'c': 'd'}

What about the empty key e if you've noticed it has been missing from all the examples which is because zip picks the shortest of the two arguments, so what are we to do.

Well one solution might be adding an empty value to odd length lists, you may choose to use append and an if statement which would do the trick, albeit slightly boring, right?

>>> if len(l) % 2:
...     l.append("")

>>> l
['a', 'b', 'c', 'd', 'e', '']

>>> dict(zip(*[iter(l)]*2))
{'a': 'b', 'c': 'd', 'e': ''}

Now before you shrug away to go type from itertools import izip_longest you may be surprised to know it is not required, we can accomplish the same, even better IMHO, with the built in functions alone.

map for longest

I prefer to use the map() function instead of izip_longest() which not only uses shorter syntax doesn't require an import but it can assign an actual None empty value when required, automagically.

>>> l = ["a", "b", "c", "d", "e"]
>>> l
['a', 'b', 'c', 'd', 'e']

>>> dict(map(None, *[iter(l)]*2))
{'a': 'b', 'c': 'd', 'e': None} 

Comparing performance of the two methods, as pointed out by KursedMetal, it is clear that the itertools module far outperforms the map function on large volumes, as a benchmark against 10 million records show.

$ time python -c 'dict(map(None, *[iter(range(10000000))]*2))'
real    0m3.755s
user    0m2.815s
sys     0m0.869s
$ time python -c 'from itertools import izip_longest; dict(izip_longest(*[iter(range(10000000))]*2, fillvalue=None))'
real    0m2.102s
user    0m1.451s
sys     0m0.539s

However the cost of importing the module has its toll on smaller datasets with map returning much quicker up to around 100 thousand records when they start arriving head to head.

$ time python -c 'dict(map(None, *[iter(range(100))]*2))'
real    0m0.046s
user    0m0.029s
sys     0m0.015s
$ time python -c 'from itertools import izip_longest; dict(izip_longest(*[iter(range(100))]*2, fillvalue=None))'
real    0m0.067s
user    0m0.042s
sys     0m0.021s

$ time python -c 'dict(map(None, *[iter(range(100000))]*2))'
real    0m0.074s
user    0m0.050s
sys     0m0.022s
$ time python -c 'from itertools import izip_longest; dict(izip_longest(*[iter(range(100000))]*2, fillvalue=None))'
real    0m0.075s
user    0m0.047s
sys     0m0.024s

See nothing to it! =)

nJoy!

Maven build Compilation error : Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project Maven

My issues was that I was running mvn compile from a child project directory instead of the parent project.

CSS change button style after click

If you're looking for a pure css option, try using the :focus pseudo class.

#style  {
    background-color: red;
}

#style:focus {     
    background-color:yellow;    
}

java.sql.SQLException: Fail to convert to internal representation

Your data types are mismatched when you are retrieving the field values.

Also check how you store your enums, default is ORDINAL (numeric value stored in database), but STRING (name of enum stored in database) is also an option. Make sure the Entity in your code and the Model in your database are exactly the same.

I had an enum mismatch. It was set to default (ORDINAL) but the database model was expecting a string VARCHAR2(100char). Solution: @Enumerated(EnumType.STRING)

python pandas dataframe to dictionary

If you want a simple way to preserve duplicates, you could use groupby:

>>> ptest = pd.DataFrame([['a',1],['a',2],['b',3]], columns=['id', 'value']) 
>>> ptest
  id  value
0  a      1
1  a      2
2  b      3
>>> {k: g["value"].tolist() for k,g in ptest.groupby("id")}
{'a': [1, 2], 'b': [3]}

How can I get jQuery to perform a synchronous, rather than asynchronous, Ajax request?

function getURL(url){
    return $.ajax({
        type: "GET",
        url: url,
        cache: false,
        async: false
    }).responseText;
}


//example use
var msg=getURL("message.php");
alert(msg);

Could not find com.android.tools.build:gradle:3.0.0-alpha1 in circle ci

For me I solved this error just by adding this line inside repository

maven { url 'https://maven.google.com' }

Call jQuery Ajax Request Each X Minutes

I found a very good jquery plugin that can ease your life with this type of operation. You can checkout https://github.com/ocombe/jQuery-keepAlive.

$.fn.keepAlive({url: 'your-route/filename', timer: 'time'},       function(response) {
        console.log(response);
      });//

How do I get hour and minutes from NSDate?

Use an NSDateFormatter to convert string1 into an NSDate, then get the required NSDateComponents:

Obj-C:

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"<your date format goes here"];
NSDate *date = [dateFormatter dateFromString:string1];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:(NSCalendarUnitHour | NSCalendarUnitMinute) fromDate:date];
NSInteger hour = [components hour];
NSInteger minute = [components minute];

Swift 1 and 2:

let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "Your date Format"
let date = dateFormatter.dateFromString(string1)
let calendar = NSCalendar.currentCalendar()
let comp = calendar.components([.Hour, .Minute], fromDate: date)
let hour = comp.hour
let minute = comp.minute

Swift 3:

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "Your date Format"
let date = dateFormatter.date(from: string1)
let calendar = Calendar.current
let comp = calendar.dateComponents([.hour, .minute], from: date)
let hour = comp.hour
let minute = comp.minute

More about the dateformat is on the official unicode site

How can I tell which button was clicked in a PHP form submit?

Are you asking in php or javascript.

If it is in php, give the name of that and use the post or get method, after that you can use the option of isset or that particular button name is checked to that value.

If it is in js, use getElementById for that

Showing all errors and warnings

PHP errors can be displayed by any of below methods:

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

For more details:

Displaying PHP errors

Underscore prefix for property and method names in JavaScript

JavaScript actually does support encapsulation, through a method that involves hiding members in closures (Crockford). That said, it's sometimes cumbersome, and the underscore convention is a pretty good convention to use for things that are sort of private, but that you don't actually need to hide.

Dynamically adding HTML form field using jQuery

You can add any type of HTML with methods like append and appendTo (among others):

jQuery manipulation methods

Example:

$('form#someform').append('<input type="text" name="something" id="something" />');

How can I clear the SQL Server query cache?

Here is some good explaination. check out it.

http://www.mssqltips.com/tip.asp?tip=1360

CHECKPOINT; 
GO 
DBCC DROPCLEANBUFFERS; 
GO

From the linked article:

If all of the performance testing is conducted in SQL Server the best approach may be to issue a CHECKPOINT and then issue the DBCC DROPCLEANBUFFERS command. Although the CHECKPOINT process is an automatic internal system process in SQL Server and occurs on a regular basis, it is important to issue this command to write all of the dirty pages for the current database to disk and clean the buffers. Then the DBCC DROPCLEANBUFFERS command can be executed to remove all buffers from the buffer pool.

How to call a SOAP web service on Android

Please download and add SOAP library file with your project File Name : ksoap2-android-assembly-3.4.0-jar-with-dependencies

Clean the application and then start program

Here is the code for SOAP service call

    String SOAP_ACTION = "YOUR_ACTION_NAME";
    String METHOD_NAME = "YOUR_METHOD_NAME";
    String NAMESPACE = "YOUR_NAME_SPACE";
    String URL = "YOUR_URL";
    SoapPrimitive resultString = null;

    try {
        SoapObject Request = new SoapObject(NAMESPACE, METHOD_NAME);
        addPropertyForSOAP(Request);

        SoapSerializationEnvelope soapEnvelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
        soapEnvelope.dotNet = true;
        soapEnvelope.setOutputSoapObject(Request);

        HttpTransportSE transport = new HttpTransportSE(URL);

        transport.call(SOAP_ACTION, soapEnvelope);
        resultString = (SoapPrimitive) soapEnvelope.getResponse();

        Log.i("SOAP Result", "Result Celsius: " + resultString);
    } catch (Exception ex) {
        Log.e("SOAP Result", "Error: " + ex.getMessage());
    }
    if(resultString != null) {
        return resultString.toString();
    }
    else{
        return "error";
    }

The results may be JSONObject or JSONArray Or String

For your better reference, https://trinitytuts.com/load-data-from-soap-web-service-in-android-application/

Thanks.

Are all Spring Framework Java Configuration injection examples buggy?

In your test, you are comparing the two TestParent beans, not the single TestedChild bean.

Also, Spring proxies your @Configuration class so that when you call one of the @Bean annotated methods, it caches the result and always returns the same object on future calls.

See here:

When do you use Git rebase instead of Git merge?

Before merge/rebase:

A <- B <- C    [master]
^
 \
  D <- E       [branch]

After git merge master:

A <- B <- C
^         ^
 \         \
  D <- E <- F

After git rebase master:

A <- B <- C <- D' <- E'

(A, B, C, D, E and F are commits)

This example and much more well illustrated information about Git can be found in Git The Basics Tutorial.

How to include *.so library in Android Studio?

*.so library in Android Studio

You have to generate jniLibs folder inside main in android Studio projects and put your all .so files inside. You can also integrate this line in build.gradle

compile fileTree(dir: 'libs', include: ['.jar','.so'])

It's work perfectly

|--app:

|--|--src:

|--|--|--main

|--|--|--|--jniLibs

|--|--|--|--|--armeabi

|--|--|--|--|--|--.so Files

This is the project structure.

In Node.js, how do I "include" functions from my other files?

You can require any js file, you just need to declare what you want to expose.

// tools.js
// ========
module.exports = {
  foo: function () {
    // whatever
  },
  bar: function () {
    // whatever
  }
};

var zemba = function () {
}

And in your app file:

// app.js
// ======
var tools = require('./tools');
console.log(typeof tools.foo); // => 'function'
console.log(typeof tools.bar); // => 'function'
console.log(typeof tools.zemba); // => undefined

How to append data to div using JavaScript?

you can use jQuery. which make it very simple.

just download the jQuery file add jQuery into your HTML
or you can user online link:

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>

and try this:

 $("#divID").append(data);

Parsing JSON Object in Java

Thank you so much to @Code in another answer. I can read any JSON file thanks to your code. Now, I'm trying to organize all the elements by levels, for could use them!

I was working with Android reading a JSON from an URL and the only I had to change was the lines

Set<Object> set = jsonObject.keySet(); Iterator<Object> iterator = set.iterator();

for

Iterator<?> iterator = jsonObject.keys();

I share my implementation, to help someone:

public void parseJson(JSONObject jsonObject) throws ParseException, JSONException {

    Iterator<?> iterator = jsonObject.keys();
    while (iterator.hasNext()) {
        String obj = iterator.next().toString();

        if (jsonObject.get(obj) instanceof JSONArray) {
            //Toast.makeText(MainActivity.this, "Objeto: JSONArray", Toast.LENGTH_SHORT).show();
            //System.out.println(obj.toString());
            TextView txtView = new TextView(this);
            txtView.setText(obj.toString());
            layoutIzq.addView(txtView);
            getArray(jsonObject.get(obj));
        } else {
            if (jsonObject.get(obj) instanceof JSONObject) {
                //Toast.makeText(MainActivity.this, "Objeto: JSONObject", Toast.LENGTH_SHORT).show();
                parseJson((JSONObject) jsonObject.get(obj));
            } else {
                //Toast.makeText(MainActivity.this, "Objeto: Value", Toast.LENGTH_SHORT).show();
                //System.out.println(obj.toString() + "\t"+ jsonObject.get(obj));
                TextView txtView = new TextView(this);
                txtView.setText(obj.toString() + "\t"+ jsonObject.get(obj));
                layoutIzq.addView(txtView);
            }
        }
    }
}

Why does checking a variable against multiple values with `OR` only check the first value?

If you want case-insensitive comparison, use lower or upper:

if name.lower() == "jesse":

Why should C++ programmers minimize use of 'new'?

One notable reason to avoid overusing the heap is for performance -- specifically involving the performance of the default memory management mechanism used by C++. While allocation can be quite quick in the trivial case, doing a lot of new and delete on objects of non-uniform size without strict order leads not only to memory fragmentation, but it also complicates the allocation algorithm and can absolutely destroy performance in certain cases.

That's the problem that memory pools where created to solve, allowing to to mitigate the inherent disadvantages of traditional heap implementations, while still allowing you to use the heap as necessary.

Better still, though, to avoid the problem altogether. If you can put it on the stack, then do so.

How to check if all list items have the same value and return it, or return an “otherValue” if they don’t?

This may be late, but an extension that works for value and reference types alike based on Eric's answer:

public static partial class Extensions
{
    public static Nullable<T> Unanimous<T>(this IEnumerable<Nullable<T>> sequence, Nullable<T> other, IEqualityComparer comparer = null)  where T : struct, IComparable
    {
        object first = null;
        foreach(var item in sequence)
        {
            if (first == null)
                first = item;
            else if (comparer != null && !comparer.Equals(first, item))
                return other;
            else if (!first.Equals(item))
                return other;
        }
        return (Nullable<T>)first ?? other;
    }

    public static T Unanimous<T>(this IEnumerable<T> sequence, T other, IEqualityComparer comparer = null)  where T : class, IComparable
    {
        object first = null;
        foreach(var item in sequence)
        {
            if (first == null)
                first = item;
            else if (comparer != null && !comparer.Equals(first, item))
                return other;
            else if (!first.Equals(item))
                return other;
        }
        return (T)first ?? other;
    }
}

How can I add (simple) tracing in C#?

DotNetCoders has a starter article on it: http://www.dotnetcoders.com/web/Articles/ShowArticle.aspx?article=50. They talk about how to set up the switches in the configuration file and how to write the code, but it is pretty old (2002).

There's another article on CodeProject: A Treatise on Using Debug and Trace classes, including Exception Handling, but it's the same age.

CodeGuru has another article on custom TraceListeners: Implementing a Custom TraceListener

Transfer data between databases with PostgreSQL

From: hxxp://dbaspot.c om/postgresql/348627-pg_dump-t-give-where-condition.html (NOTE: the link is now broken)

# create temp table with the data
psql mydb
CREATE TABLE temp1 (LIKE mytable);
INSERT INTO temp1 SELECT * FROM mytable WHERE myconditions;
\q

# export the data to a sql file
pg_dump --data-only --column-inserts -t temp1 mtdb > out.sql
psql mydb
DROP TABLE temp1;
\q

# import temp1 rows in another database
cat out.sql | psql -d [other_db]
psql other_db
INSERT INTO mytable (SELECT * FROM temp1);
DROP TABLE temp1;

Another method useful in remotes

  # export a table csv and import in another database
  psql-remote> COPY elements TO '/tmp/elements.csv' DELIMITER ',' CSV HEADER;
  $ scp host.com:/tmp/elements.csv /tmp/elements.csv
  psql-local> COPY elements FROM '/tmp/elements.csv' DELIMITER ',' CSV;

center image in div with overflow hidden

working solution with flex-box for posterity:

main points:

  1. overflow hidden for wrapper
  2. image height and width must be specified, cannot be percentage.
  3. use any method you want to center the image.
  wrapper {
    width: 80;
    height: 80;
    overflow: hidden;
    align-items: center;
    justify-content: center;
  }
  image {
    width: min-content;
    height: min-content;
  }

What is the purpose for using OPTION(MAXDOP 1) in SQL Server?

This is a general rambling on Parallelism in SQL Server, it might not answer your question directly.

From Books Online, on MAXDOP:

Sets the maximum number of processors the query processor can use to execute a single index statement. Fewer processors may be used depending on the current system workload.

See Rickie Lee's blog on parallelism and CXPACKET wait type. It's quite interesting.

Generally, in an OLTP database, my opinion is that if a query is so costly it needs to be executed on several processors, the query needs to be re-written into something more efficient.

Why you get better results adding MAXDOP(1)? Hard to tell without the actual execution plans, but it might be so simple as that the execution plan is totally different that without the OPTION, for instance using a different index (or more likely) JOINing differently, using MERGE or HASH joins.

How can I create a UIColor from a hex string?

I've got a solution that is 100% compatible with the hex format strings used by Android, which I found very helpful when doing cross-platform mobile development. It lets me use one color palate for both platforms. Feel free to reuse without attribution, or under the Apache license if you prefer.

#import "UIColor+HexString.h"

@interface UIColor(HexString)

+ (UIColor *) colorWithHexString: (NSString *) hexString;
+ (CGFloat) colorComponentFrom: (NSString *) string start: (NSUInteger) start length: (NSUInteger) length;

@end


@implementation UIColor(HexString)

+ (UIColor *) colorWithHexString: (NSString *) hexString {
    NSString *colorString = [[hexString stringByReplacingOccurrencesOfString: @"#" withString: @""] uppercaseString];
    CGFloat alpha, red, blue, green;
    switch ([colorString length]) {
        case 3: // #RGB
            alpha = 1.0f;
            red   = [self colorComponentFrom: colorString start: 0 length: 1];
            green = [self colorComponentFrom: colorString start: 1 length: 1];
            blue  = [self colorComponentFrom: colorString start: 2 length: 1];
            break;
        case 4: // #ARGB
            alpha = [self colorComponentFrom: colorString start: 0 length: 1];
            red   = [self colorComponentFrom: colorString start: 1 length: 1];
            green = [self colorComponentFrom: colorString start: 2 length: 1];
            blue  = [self colorComponentFrom: colorString start: 3 length: 1];          
            break;
        case 6: // #RRGGBB
            alpha = 1.0f;
            red   = [self colorComponentFrom: colorString start: 0 length: 2];
            green = [self colorComponentFrom: colorString start: 2 length: 2];
            blue  = [self colorComponentFrom: colorString start: 4 length: 2];                      
            break;
        case 8: // #AARRGGBB
            alpha = [self colorComponentFrom: colorString start: 0 length: 2];
            red   = [self colorComponentFrom: colorString start: 2 length: 2];
            green = [self colorComponentFrom: colorString start: 4 length: 2];
            blue  = [self colorComponentFrom: colorString start: 6 length: 2];                      
            break;
        default:
            [NSException raise:@"Invalid color value" format: @"Color value %@ is invalid.  It should be a hex value of the form #RBG, #ARGB, #RRGGBB, or #AARRGGBB", hexString];
            break;
    }
    return [UIColor colorWithRed: red green: green blue: blue alpha: alpha];
}

+ (CGFloat) colorComponentFrom: (NSString *) string start: (NSUInteger) start length: (NSUInteger) length {
    NSString *substring = [string substringWithRange: NSMakeRange(start, length)];
    NSString *fullHex = length == 2 ? substring : [NSString stringWithFormat: @"%@%@", substring, substring];
    unsigned hexComponent;
    [[NSScanner scannerWithString: fullHex] scanHexInt: &hexComponent];
    return hexComponent / 255.0;
}

@end 

CSS3 Spin Animation

For the sake of completion, here's a Sass / Compass example which really shortens the code, the compiled CSS will include the necessary prefixes etc.

div
  margin: 20px
  width: 100px 
  height: 100px    
  background: #f00
  +animation(spin 40000ms infinite linear)

+keyframes(spin)
  from
    +transform(rotate(0deg))
  to
    +transform(rotate(360deg))

Read and Write CSV files including unicode with Python 2.7

Make sure you encode and decode as appropriate.

This example will roundtrip some example text in utf-8 to a csv file and back out to demonstrate:

# -*- coding: utf-8 -*-
import csv

tests={'German': [u'Straße',u'auslösen',u'zerstören'], 
       'French': [u'français',u'américaine',u'épais'], 
       'Chinese': [u'???',u'??',u'???']}

with open('/tmp/utf.csv','w') as fout:
    writer=csv.writer(fout)    
    writer.writerows([tests.keys()])
    for row in zip(*tests.values()):
        row=[s.encode('utf-8') for s in row]
        writer.writerows([row])

with open('/tmp/utf.csv','r') as fin:
    reader=csv.reader(fin)
    for row in reader:
        temp=list(row)
        fmt=u'{:<15}'*len(temp)
        print fmt.format(*[s.decode('utf-8') for s in temp])

Prints:

German         Chinese        French         
Straße         ???            français       
auslösen       ??             américaine     
zerstören      ???            épais  

How to Copy Text to Clip Board in Android?

As a handy kotlin extension:

fun Context.copyToClipboard(text: CharSequence){
    val clipboard = getSystemService(Context.CLIPBOARD_SERVICE) as ClipboardManager
    val clip = ClipData.newPlainText("label",text)
    clipboard.setPrimaryClip(clip)
}

Update:

If you using ContextCompat you should use:

ContextCompat.getSystemService(this, ClipboardManager::class.java)

Completely remove MariaDB or MySQL from CentOS 7 or RHEL 7

To update and answer the question without breaking mail servers. Later versions of CentOS 7 have MariaDB included as the base along with PostFix which relies on MariaDB. Removing using yum will also remove postfix and perl-DBD-MySQL. To get around this and keep postfix in place, first make a copy of /usr/lib64/libmysqlclient.so.18 (which is what postfix depends on) and then use:

rpm -qa | grep mariadb

then remove the mariadb packages using (changing to your versions):

rpm -e --nodeps "mariadb-libs-5.5.56-2.el7.x86_64"
rpm -e --nodeps "mariadb-server-5.5.56-2.el7.x86_64"
rpm -e --nodeps "mariadb-5.5.56-2.el7.x86_64"

Delete left over files and folders (which also removes any databases):

rm -f /var/log/mariadb
rm -f /var/log/mariadb/mariadb.log.rpmsave
rm -rf /var/lib/mysql
rm -rf /usr/lib64/mysql
rm -rf /usr/share/mysql

Put back the copy of /usr/lib64/libmysqlclient.so.18 you made at the start and you can restart postfix.

There is more detail at https://code.trev.id.au/centos-7-remove-mariadb-replace-mysql/ which describes how to replace mariaDB with MySQL

OS specific instructions in CMAKE: How to?

Given this is such a common issue, geronto-posting:

    if(UNIX AND NOT APPLE)
        set(LINUX TRUE)
    endif()

    # if(NOT LINUX) should work, too, if you need that
    if(LINUX) 
        message(STATUS ">>> Linux")
        # linux stuff here
    else()
        message(STATUS ">>> Not Linux")
        # stuff that should happen not on Linux 
    endif()

CMake boolean logic docs

CMake platform names, etc.

What is Join() in jQuery?

I use join to separate the word in array with "and, or , / , &"

EXAMPLE

HTML

<p>London Mexico Canada</p>
<div></div>

JS

 newText = $("p").text().split(" ").join(" or ");
 $('div').text(newText);

Results

London or Mexico or Canada

How to add List<> to a List<> in asp.net

Use .AddRange to append any Enumrable collection to the list.

Convert all data frame character columns to factors

The easiest way would be to use the code given below. It would automate the whole process of converting all the variables as factors in a dataframe in R. it worked perfectly fine for me. food_cat here is the dataset which I am using. Change it to the one which you are working on.

    for(i in 1:ncol(food_cat)){

food_cat[,i] <- as.factor(food_cat[,i])

}

PHP Function with Optional Parameters

You can just set the default value to null.

<?php
function functionName($value, $value2 = null) {
// do stuff
}

Why are static variables considered evil?

I have just summarized some of the points made in the answers. If you find anything wrong please feel free to correct it.

Scaling: We have exactly one instance of a static variable per JVM. Suppose we are developing a library management system and we decided to put the name of book a static variable as there is only one per book. But if system grows and we are using multiple JVMs then we dont have a way to figure out which book we are dealing with?

Thread-Safety: Both instance variable and static variable need to be controlled when used in multi threaded environment. But in case of an instance variable it does not need protection unless it is explicitly shared between threads but in case of a static variable it is always shared by all the threads in the process.

Testing: Though testable design does not equal to good design but we will rarely observe a good design that is not testable. As static variables represent global state and it gets very difficult to test them.

Reasoning about state: If I create a new instance of a class then we can reason about the state of this instance but if it is having static variables then it could be in any state. Why? Because it is possible that the static variable has been modified by some different instance as static variable is shared across instances.

Serialization: Serialization also does not work well with them.

Creation and destruction: Creation and destruction of static variables can not be controlled. Usually they are created and destroyed at program loading and unloading time. It means they are bad for memory management and also add up the initialization time at start up.

But what if we really need them?

But sometimes we may have a genuine need of them. If we really feel the need of many static variables that are shared across the application then one option is to make use of Singleton Design pattern which will have all these variables. Or we can create some object which will have these static variable and can be passed around.

Also if the static variable is marked final it becomes a constant and value assigned to it once cannot be changed. It means it will save us from all the problems we face due to its mutability.

Granting Rights on Stored Procedure to another user of Oracle

On your DBA account, give USERB the right to create a procedure using grant grant create any procedure to USERB

The procedure will look

CREATE OR REPLACE PROCEDURE USERB.USERB_PROCEDURE
--Must add the line below
AUTHID CURRENT_USER AS
  BEGIN
  --DO SOMETHING HERE
  END
END

GRANT EXECUTE ON USERB.USERB_PROCEDURE TO USERA

I know this is a very old question but I am hoping I could chip it a bit.

How to edit CSS style of a div using C# in .NET

Add runat to the element in the markup

<div id="formSpinner" runat="server">
    <img src="images/spinner.gif">
    <p>Saving...</p>
</div

Then you can get to the control's class attributes by using formSpinner.Attributes("class") It will only be a string, but you should be able to edit it.

Segmentation Fault - C

Your scanf("%s", s); is commented out. That means s is uninitialized, so when this line ln = strlen(s); executes, you get a seg fault.

It always helps to initialize a pointer to NULL, and then test for null before using the pointer.

How to sort an associative array by its values in Javascript?

The best approach for the specific case here, in my opinion, is the one commonpike suggested. A little improvement I'd suggest that works in modern browsers is:

// aao is the "associative array" you need to "sort"
Object.keys(aao).sort(function(a,b){return aao[b]-aao[a]});

This could apply easily and work great in the specific case here so you can do:

let aoo={};
aao["sub2"]=1;
aao["sub0"]=-1;
aao["sub1"]=0;
aao["sub3"]=1;
aao["sub4"]=0;

let sk=Object.keys(aao).sort(function(a,b){return aao[b]-aao[a]});

// now you can loop using the sorted keys in `sk` to do stuffs
for (let i=sk.length-1;i>=0;--i){
 // do something with sk[i] or aoo[sk[i]]
}

Besides of this, I provide here a more "generic" function you can use to sort even in wider range of situations and that mixes the improvement I just suggested with the approaches of the answers by Ben Blank (sorting also string values) and PopeJohnPaulII (sorting by specific object field/property) and lets you decide if you want an ascendant or descendant order, here it is:

// aao := is the "associative array" you need to "sort"
// comp := is the "field" you want to compare or "" if you have no "fields" and simply need to compare values
// intVal := must be false if you need comparing non-integer values
// desc := set to true will sort keys in descendant order (default sort order is ascendant)
function sortedKeys(aao,comp="",intVal=false,desc=false){
  let keys=Object.keys(aao);
  if (comp!="") {
    if (intVal) {
      if (desc) return keys.sort(function(a,b){return aao[b][comp]-aao[a][comp]});
      else return keys.sort(function(a,b){return aao[a][comp]-aao[a][comp]});
    } else {
      if (desc) return keys.sort(function(a,b){return aao[b][comp]<aao[a][comp]?1:aao[b][comp]>aao[a][comp]?-1:0});
      else return keys.sort(function(a,b){return aao[a][comp]<aao[b][comp]?1:aao[a][comp]>aao[b][comp]?-1:0});
    }
  } else {
    if (intVal) {
      if (desc) return keys.sort(function(a,b){return aao[b]-aao[a]});
      else return keys.sort(function(a,b){return aao[a]-aao[b]});
    } else {
      if (desc) return keys.sort(function(a,b){return aao[b]<aao[a]?1:aao[b]>aao[a]?-1:0});
      else return keys.sort(function(a,b){return aao[a]<aao[b]?1:aao[a]>aao[b]?-1:0});
    }
  }
}

You can test the functionalities trying something like the following code:

let items={};
items['Edward']=21;
items['Sharpe']=37;
items['And']=45;
items['The']=-12;
items['Magnetic']=13;
items['Zeros']=37;
//equivalent to:
//let items={"Edward": 21, "Sharpe": 37, "And": 45, "The": -12, ...};

console.log("1: "+sortedKeys(items));
console.log("2: "+sortedKeys(items,"",false,true));
console.log("3: "+sortedKeys(items,"",true,false));
console.log("4: "+sortedKeys(items,"",true,true));
/* OUTPUT
1: And,Sharpe,Zeros,Edward,Magnetic,The
2: The,Magnetic,Edward,Sharpe,Zeros,And
3: The,Magnetic,Edward,Sharpe,Zeros,And
4: And,Sharpe,Zeros,Edward,Magnetic,The
*/

items={};
items['k1']={name:'Edward',value:21};
items['k2']={name:'Sharpe',value:37};
items['k3']={name:'And',value:45};
items['k4']={name:'The',value:-12};
items['k5']={name:'Magnetic',value:13};
items['k6']={name:'Zeros',value:37};

console.log("1: "+sortedKeys(items,"name"));
console.log("2: "+sortedKeys(items,"name",false,true));
/* OUTPUT
1: k6,k4,k2,k5,k1,k3
2: k3,k1,k5,k2,k4,k6
*/

As I already said, you can loop over sorted keys if you need doing stuffs

let sk=sortedKeys(aoo);
// now you can loop using the sorted keys in `sk` to do stuffs
for (let i=sk.length-1;i>=0;--i){
 // do something with sk[i] or aoo[sk[i]]
}

Last, but not least, some useful references to Object.keys and Array.sort

Call PHP function from Twig template

If you really know what you do and you don't mind the evil ways, this is the only additional Twig extension you'll ever need:

function evilEvalPhp($eval, $args = null)
{
    $result = null;
    eval($eval);
    return $result;
}

Creating a URL in the controller .NET MVC

I know this is an old question, but just in case you are trying to do the same thing in ASP.NET Core, here is how you can create the UrlHelper inside an action:

var urlHelper = new UrlHelper(this.ControllerContext);

Or, you could just use the Controller.Url property if you inherit from Controller.

How to remove the default arrow icon from a dropdown list (select element)?

As I answered in Remove Select arrow on IE

In case you want to use the class and pseudo-class:

.simple-control is your css class

:disabled is pseudo class

select.simple-control:disabled{
         /*For FireFox*/
        -webkit-appearance: none;
        /*For Chrome*/
        -moz-appearance: none;
}

/*For IE10+*/
select:disabled.simple-control::-ms-expand {
        display: none;
}

Generate pdf from HTML in div using Javascript

One way is to use window.print() function. Which does not require any library

Pros

1.No external library require.

2.We can print only selected parts of body also.

3.No css conflicts and js issues.

4.Core html/js functionality

---Simply add below code

CSS to

@media print {
        body * {
            visibility: hidden; // part to hide at the time of print
            -webkit-print-color-adjust: exact !important; // not necessary use         
               if colors not visible
        }

        #printBtn {
            visibility: hidden !important; // To hide 
        }

        #page-wrapper * {
            visibility: visible; // Print only required part
            text-align: left;
            -webkit-print-color-adjust: exact !important;
        }
    }

JS code - Call bewlow function on btn click

$scope.printWindow = function () {
  window.print()
}

Note: Use !important in every css object

Example -

.legend  {
  background: #9DD2E2 !important;
}

Cannot find firefox binary in PATH. Make sure firefox is installed

Did you add firefox to your path after you have started the selenium server? If that is the case selenium will still use old path. The solution is to tear down & restart selenium so that it will use the updated Path environment variable.

To check if firefox is added in your path correctly you can just launch a command line terminal "cmd" and type "firefox" + ENTER there. If firefox starts then everything is alright and restarting selenium server should fix the problem.

json_encode sparse PHP array as JSON array, not JSON object

Try this,

<?php
$arr1=array('result1'=>'abcd','result2'=>'efg'); 
$arr2=array('result1'=>'hijk','result2'=>'lmn'); 
$arr3=array($arr1,$arr2); 
print (json_encode($arr3)); 
?>

Easy way to test a URL for 404 in PHP?

As an additional hint to the great accepted answer:

When using a variation of the proposed solution, I got errors because of php setting 'max_execution_time'. So what I did was the following:

set_time_limit(120);
$curl = curl_init($url);
curl_setopt($curl, CURLOPT_NOBODY, true);
$result = curl_exec($curl);
set_time_limit(ini_get('max_execution_time'));
curl_close($curl);

First I set the time limit to a higher number of seconds, in the end I set it back to the value defined in the php settings.

Url decode UTF-8 in Python

The data is UTF-8 encoded bytes escaped with URL quoting, so you want to decode, with urllib.parse.unquote(), which handles decoding from percent-encoded data to UTF-8 bytes and then to text, transparently:

from urllib.parse import unquote

url = unquote(url)

Demo:

>>> from urllib.parse import unquote
>>> url = 'example.com?title=%D0%BF%D1%80%D0%B0%D0%B2%D0%BE%D0%B2%D0%B0%D1%8F+%D0%B7%D0%B0%D1%89%D0%B8%D1%82%D0%B0'
>>> unquote(url)
'example.com?title=????????+??????'

The Python 2 equivalent is urllib.unquote(), but this returns a bytestring, so you'd have to decode manually:

from urllib import unquote

url = unquote(url).decode('utf8')

How to set timeout for a line of c# code

I use something like this (you should add code to deal with the various fails):

    var response = RunTaskWithTimeout<ReturnType>(
        (Func<ReturnType>)delegate { return SomeMethod(someInput); }, 30);


    /// <summary>
    /// Generic method to run a task on a background thread with a specific timeout, if the task fails,
    /// notifies a user
    /// </summary>
    /// <typeparam name="T">Return type of function</typeparam>
    /// <param name="TaskAction">Function delegate for task to perform</param>
    /// <param name="TimeoutSeconds">Time to allow before task times out</param>
    /// <returns></returns>
    private T RunTaskWithTimeout<T>(Func<T> TaskAction, int TimeoutSeconds)
    {
        Task<T> backgroundTask;

        try
        {
            backgroundTask = Task.Factory.StartNew(TaskAction);
            backgroundTask.Wait(new TimeSpan(0, 0, TimeoutSeconds));
        }
        catch (AggregateException ex)
        {
            // task failed
            var failMessage = ex.Flatten().InnerException.Message);
            return default(T);
        }
        catch (Exception ex)
        {
            // task failed
            var failMessage = ex.Message;
            return default(T);
        }

        if (!backgroundTask.IsCompleted)
        {
            // task timed out
            return default(T);
        }

        // task succeeded
        return backgroundTask.Result;
    }

Find out free space on tablespace

The following query will help to find out free space of tablespaces in MB:

select tablespace_name , sum(bytes)/1024/1024 from dba_free_space group by tablespacE_name order by 1;

Way to run Excel macros from command line or batch file?

I'm partial to C#. I ran the following using linqpad. But it could just as easily be compiled with csc and ran through the called from the command line.

Don't forget to add excel packages to namespace.

void Main()
{
    var oExcelApp = (Microsoft.Office.Interop.Excel.Application)System.Runtime.InteropServices.Marshal.GetActiveObject("Excel.Application");
    try{
        var WB = oExcelApp.ActiveWorkbook;
        var WS = (Worksheet)WB.ActiveSheet;
        ((string)((Range)WS.Cells[1,1]).Value).Dump("Cell Value"); //cel A1 val
        oExcelApp.Run("test_macro_name").Dump("macro");
    }
    finally{
        if(oExcelApp != null)
            System.Runtime.InteropServices.Marshal.ReleaseComObject(oExcelApp);
        oExcelApp = null;
    }
}

Can I give the col-md-1.5 in bootstrap?

you can use this code inside col-md-3 , col-md-9

.col-side-right{
  flex: 0 0 20% !important;
  max-width: 20%;
}

.col-side-left{
  flex: 0 0 80%;
  max-width: 80%;
}

How to split a string of space separated numbers into integers?

Just use strip() to remove empty spaces and apply explicit int conversion on the variable.

Ex:

a='1  ,  2, 4 ,6 '
f=[int(i.strip()) for i in a]

What is a stored procedure?

A stored procedure is a named collection of SQL statements and procedural logic i.e, compiled, verified and stored in the server database. A stored procedure is typically treated like other database objects and controlled through server security mechanism.

What is the difference between Tomcat, JBoss and Glassfish?

Tomcat is just a servlet container, i.e. it implements only the servlets and JSP specification. Glassfish and JBoss are full Java EE servers (including stuff like EJB, JMS, ...), with Glassfish being the reference implementation of the latest Java EE 6 stack, but JBoss in 2010 was not fully supporting it yet.

How to switch from POST to GET in PHP CURL

CURL request by default is GET, you don't have to set any options to make a GET CURL request.

LINQ: Distinct values

For any one still looking; here's another way of implementing a custom lambda comparer.

public class LambdaComparer<T> : IEqualityComparer<T>
    {
        private readonly Func<T, T, bool> _expression;

        public LambdaComparer(Func<T, T, bool> lambda)
        {
            _expression = lambda;
        }

        public bool Equals(T x, T y)
        {
            return _expression(x, y);
        }

        public int GetHashCode(T obj)
        {
            /*
             If you just return 0 for the hash the Equals comparer will kick in. 
             The underlying evaluation checks the hash and then short circuits the evaluation if it is false.
             Otherwise, it checks the Equals. If you force the hash to be true (by assuming 0 for both objects), 
             you will always fall through to the Equals check which is what we are always going for.
            */
            return 0;
        }
    }

you can then create an extension for the linq Distinct that can take in lambda's

   public static IEnumerable<T> Distinct<T>(this IEnumerable<T> list,  Func<T, T, bool> lambda)
        {
            return list.Distinct(new LambdaComparer<T>(lambda));
        }  

Usage:

var availableItems = list.Distinct((p, p1) => p.Id== p1.Id);

"SetPropertiesRule" warning message when starting Tomcat from Eclipse

I am posting my answer because I suspect there might be someone out there for whom the above solutions might not have worked.

So, you are getting a warning,

WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server: (project name)' did not find a matching property.

Rather than disabling this warning by checking that option in Server configuration (I did try that) I would suggest you do this:

  1. First close all the existing projects by right clicking in Project explorer.
  2. Remove all the projects already synchronized with the server.
  3. Remove the server and redeploy it.
  4. Create a new dynamic project, do nothing yet just try running this on the server.
  5. Check the console, do you get the warning now. (My case I didn't get any).
    This means that something is wrong with your project not with eclipse or the server.
  6. Now restart the server. Don't run any app yet.
    You probably know that the Tomcat container loads up context of all the synchronized apps at the start.
  7. It will load context of any already synchronized app.
  8. Here is the catch, if there is really something wrong in your project it will show the stack trace of the exceptions.Look carefully and you will find where is the bug in your app.

Now if you successfully found that there is a bug in your app, the probable place would be look for a web.xml file which the container uses for loading the app. In my case I had misspelled a name in servlet mapping which made me debug meaninglessly for 3 hours. Your problem might be someplace else.

And another thing, if you have many apps synchronized with the server,there is a possibility some other app's context might be the source of problem. Try debugging one by one.

What arguments are passed into AsyncTask<arg1, arg2, arg3>?

I'm too late to the party but thought this might help someone.

How can I define fieldset border color?

It works for me when I define the complete border property. (JSFiddle here)

.field_set{
 border: 1px #F00 solid;
}?

the reason is the border-style that is set to none by default for fieldsets. You need to override that as well.

What is the cause for "angular is not defined"

You have not placed the script tags for angular js

you can do so by using cdn or downloading the angularjs for your project and then referencing it

after this you have to add your own java script in your case main.js

that should do

Cannot enqueue Handshake after invoking quit

inplace of connection.connect(); use -

if(!connection._connectCalled ) 
{
connection.connect();
}

if it is already called then connection._connectCalled =true,
& it will not execute connection.connect();

note - don't use connection.end();

Shortest way to check for null and assign another value if not

With C#6 there is a slightly shorter way for the case where planRec.approved_by is not a string:

this.approved_by = planRec.approved_by?.ToString() ?? "";

std::string formatting like sprintf

Here my (simple solution):

std::string Format(const char* lpszFormat, ...)
{
    // Warning : "vsnprintf" crashes with an access violation
    // exception if lpszFormat is not a "const char*" (for example, const string&)

    size_t  nSize     = 1024;
    char    *lpBuffer = (char*)malloc(nSize);

    va_list lpParams;

    while (true)
    {
        va_start(lpParams, lpszFormat);

        int nResult = vsnprintf(
            lpBuffer,
            nSize,
            lpszFormat,
            lpParams
        );

        va_end(lpParams);

        if ((nResult >= 0) && (nResult < (int)nSize) )
        {
            // Success

            lpBuffer[nResult] = '\0';
            std::string sResult(lpBuffer);

            free (lpBuffer);

            return sResult;
        }
        else
        {
            // Increase buffer

            nSize =
                  (nResult < 0)
                ? nSize *= 2
                : (nResult + 1)
            ;

            lpBuffer = (char *)realloc(lpBuffer, nSize);
        }
    }
}

AWS S3 - How to fix 'The request signature we calculated does not match the signature' error?

Got this error while uploading document to CloudSearch through Java SDK. The issue was because of a special character in the document to be uploaded. The error "The request signature we calculated does not match the signature you provided. Check your AWS Secret Access Key and signing method." is very misleading.

Print a variable in hexadecimal in Python

You can try something like this I guess:

new_str = ""
str_value = "rojbasr"
for i in str_value:
    new_str += "0x%s " % (i.encode('hex'))
print new_str

Your output would be something like this:

0x72 0x6f 0x6a 0x62 0x61 0x73 0x72

Error:(1, 0) Plugin with id 'com.android.application' not found

In my case, I download the project from GitHub and the Gradle file was missing. So I just create a new project with success build. Then copy-paste the Gradle missing file. And re-build the project is working for me.

enter image description here

MySQL Creating tables with Foreign Keys giving errno: 150

MySQL’s generic “errno 150” message “means that a foreign key constraint was not correctly formed.” As you probably already know if you are reading this page, the generic “errno: 150” error message is really unhelpful. However:

You can get the actual error message by running SHOW ENGINE INNODB STATUS; and then looking for LATEST FOREIGN KEY ERROR in the output.

For example, this attempt to create a foreign key constraint:

CREATE TABLE t1
(id INTEGER);

CREATE TABLE t2
(t1_id INTEGER,
 CONSTRAINT FOREIGN KEY (t1_id) REFERENCES t1 (id));

fails with the error Can't create table 'test.t2' (errno: 150). That doesn’t tell anyone anything useful other than that it’s a foreign key problem. But run SHOW ENGINE INNODB STATUS; and it will say:

------------------------
LATEST FOREIGN KEY ERROR
------------------------
130811 23:36:38 Error in foreign key constraint of table test/t2:
FOREIGN KEY (t1_id) REFERENCES t1 (id)):
Cannot find an index in the referenced table where the
referenced columns appear as the first columns, or column types
in the table and the referenced table do not match for constraint.

It says that the problem is it can’t find an index. SHOW INDEX FROM t1 shows that there aren’t any indexes at all for table t1. Fix that by, say, defining a primary key on t1, and the foreign key constraint will be created successfully.

How to get my activity context?

You can use Application class(public class in android.application package),that is:

Base class for those who need to maintain global application state. You can provide your own implementation by specifying its name in your AndroidManifest.xml's tag, which will cause that class to be instantiated for you when the process for your application/package is created.

To use this class do:

public class App extends Application {

    private static Context mContext;

    public static Context getContext() {
        return mContext;
    }

    public static void setContext(Context mContext) {
        this.mContext = mContext;
    }

    ...

}

In your manifest:

<application
        android:icon="..."
        android:label="..."
        android:name="com.example.yourmainpackagename.App" >
                       class that extends Application ^^^

In Activity B:

public class B extends Activity {

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.sampleactivitylayout);

        App.setContext(this);
                  ...
        }
...
}

In class A:

Context c = App.getContext();

Note:

There is normally no need to subclass Application. In most situation, static singletons can provide the same functionality in a more modular way. If your singleton needs a global context (for example to register broadcast receivers), the function to retrieve it can be given a Context which internally uses Context.getApplicationContext() when first constructing the singleton.

C++ STL Vectors: Get iterator from index?

Also; auto it = std::next(v.begin(), index);

Update: Needs a C++11x compliant compiler

Suppress warning messages using mysql from within Terminal, but password written in bash script

ok, solution without temporary files or anything:

mysql --defaults-extra-file=<(echo $'[client]\npassword='"$password") -u $user -e "statement"

it is similar to what others have mentioned, but here you don't need an actual file, this part of the command fakes the file: <(echo ...) (notice there is no space in the middle of <(

Getting the Username from the HKEY_USERS values

In the HKEY_USERS\oneyouwanttoknow\ you can look at \Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders and it will reveal their profile paths. c:\users\whothisis\Desktop, etc.

Putting text in top left corner of matplotlib plot

You can use text.

text(x, y, s, fontsize=12)

text coordinates can be given relative to the axis, so the position of your text will be independent of the size of the plot:

The default transform specifies that text is in data coords, alternatively, you can specify text in axis coords (0,0 is lower-left and 1,1 is upper-right). The example below places text in the center of the axes::

text(0.5, 0.5,'matplotlib',
     horizontalalignment='center',
     verticalalignment='center',
     transform = ax.transAxes)

To prevent the text to interfere with any point of your scatter is more difficult afaik. The easier method is to set y_axis (ymax in ylim((ymin,ymax))) to a value a bit higher than the max y-coordinate of your points. In this way you will always have this free space for the text.

EDIT: here you have an example:

In [17]: from pylab import figure, text, scatter, show
In [18]: f = figure()
In [19]: ax = f.add_subplot(111)
In [20]: scatter([3,5,2,6,8],[5,3,2,1,5])
Out[20]: <matplotlib.collections.CircleCollection object at 0x0000000007439A90>
In [21]: text(0.1, 0.9,'matplotlib', ha='center', va='center', transform=ax.transAxes)
Out[21]: <matplotlib.text.Text object at 0x0000000007415B38>
In [22]:

enter image description here

The ha and va parameters set the alignment of your text relative to the insertion point. ie. ha='left' is a good set to prevent a long text to go out of the left axis when the frame is reduced (made narrower) manually.

How to display my application's errors in JSF?

Simple answer, if you don't need to bind it to a specific component...

Java:

            FacesMessage message = new FacesMessage(FacesMessage.SEVERITY_ERROR, "Authentication failed", null);
            FacesContext context = FacesContext.getCurrentInstance();
            context.addMessage(null, message);      

XHTML:

            <h:messages></h:messages>

Using Pip to install packages to Anaconda Environment

if you're using windows OS open Anaconda Prompt and type activate yourenvname

And if you're using mac or Linux OS open Terminal and type source activate yourenvname

yourenvname here is your desired environment in which you want to install pip package

after typing above command you must see that your environment name is changed from base to your typed environment yourenvname in console output (which means you're now in your desired environment context)

Then all you need to do is normal pip install command e.g pip install yourpackage

By doing so, the pip package will be installed in your Conda environment

How to delete selected text in the vi editor

If you want to delete using line numbers you can use:

:startingline, last line d

Example:

:7,20 d

This example will delete line 7 to 20.

How can I deserialize JSON to a simple Dictionary<string,string> in ASP.NET?

Tried to not use any external JSON implementation so i deserialised like this:

string json = "{\"id\":\"13\", \"value\": true}";

var serializer = new JavaScriptSerializer(); //using System.Web.Script.Serialization;

Dictionary<string, string> values = serializer.Deserialize<Dictionary<string, string>>(json);

Check if enum exists in Java

Just use valueOf() method. If the value doesn't exist, it throws IllegalArgumentException and you can catch it like that:

      boolean isSettingCodeValid = true;

       try {
            SettingCode.valueOf(settingCode.toUpperCase());
        } catch (IllegalArgumentException e) {
            // throw custom exception or change the isSettingCodeValid value
            isSettingCodeValid = false;
        }

Jquery bind double click and single click separately

If you don't want to create separate variables to manage the state, you can check this answer https://stackoverflow.com/a/65620562/4437468

Regex to match any character including new lines

You want to use "multiline".

$string =~ /(START)(.+?)(END)/m;