Programs & Examples On #Sum

The 'sum' function which returns the sum of the items in an array.

How get total sum from input box values using Javascript?

Try:

Qty1 : <input onblur="findTotal()" type="text" name="qty" id="qty1"/><br>
Qty2 : <input onblur="findTotal()" type="text" name="qty" id="qty2"/><br>
Qty3 : <input onblur="findTotal()" type="text" name="qty" id="qty3"/><br>
Qty4 : <input onblur="findTotal()" type="text" name="qty" id="qty4"/><br>
Qty5 : <input onblur="findTotal()" type="text" name="qty" id="qty5"/><br>
Qty6 : <input onblur="findTotal()" type="text" name="qty" id="qty6"/><br>
Qty7 : <input onblur="findTotal()" type="text" name="qty" id="qty7"/><br>
Qty8 : <input onblur="findTotal()" type="text" name="qty" id="qty8"/><br>
<br><br>
Total : <input type="text" name="total" id="total"/>


    <script type="text/javascript">
function findTotal(){
    var arr = document.getElementsByName('qty');
    var tot=0;
    for(var i=0;i<arr.length;i++){
        if(parseInt(arr[i].value))
            tot += parseInt(arr[i].value);
    }
    document.getElementById('total').value = tot;
}

    </script>

SELECT query with CASE condition and SUM()

Use an "Or"

Select SUM(CAmount) as PaymentAmount 
from TableOrderPayment 
where (CPaymentType='Check' Or CPaymentType='Cash')
   and CDate <= case CPaymentType When 'Check' Then SYSDATETIME() else CDate End
   and CStatus='" & "Active" & "'"

or an "IN"

Select SUM(CAmount) as PaymentAmount 
from TableOrderPayment 
where CPaymentType IN ('Check', 'Cash')
   and CDate <= case CPaymentType When 'Check' Then SYSDATETIME() else CDate End
   and CStatus='" & "Active" & "'"

How to sum all the values in a dictionary?

d = {'key1': 1,'key2': 14,'key3': 47}
sum1 = sum(d[item] for item in d)
print(sum1)

you can do it using the for loop

Sum a list of numbers in Python

Try the following -

mylist = [1, 2, 3, 4]   

def add(mylist):
    total = 0
    for i in mylist:
        total += i
    return total

result = add(mylist)
print("sum = ", result)

Iterating over arrays in Python 3

When you loop in an array like you did, your for variable(in this example i) is current element of your array.

For example if your ar is [1,5,10], the i value in each iteration is 1, 5, and 10. And because your array length is 3, the maximum index you can use is 2. so when i = 5 you get IndexError. You should change your code into something like this:

for i in ar:
    theSum = theSum + i

Or if you want to use indexes, you should create a range from 0 ro array length - 1.

for i in range(len(ar)):
    theSum = theSum + ar[i]

MYSQL Sum Query with IF Condition

Try with a CASE in this way :

SUM(CASE 
    WHEN PaymentType = "credit card" 
    THEN TotalAmount 
    ELSE 0 
END) AS CreditCardTotal,

Should give what you are looking for ...

How to sum data.frame column values?

You can just use sum(people$Weight).

sum sums up a vector, and people$Weight retrieves the weight column from your data frame.

Note - you can get built-in help by using ?sum, ?colSums, etc. (by the way, colSums will give you the sum for each column).

SQL Sum Multiple rows into one

Thank you for your responses. Turns out my problem was a database issue with duplicate entries, not with my logic. A quick table sync fixed that and the SUM feature worked as expected. This is all still useful knowledge for the SUM feature and is worth reading if you are having trouble using it.

C# List of objects, how do I get the sum of a property

Here is example code you could run to make such test:

var f = 10000000;
var p = new int[f];

for(int i = 0; i < f; ++i)
{
    p[i] = i % 2;
}

var time = DateTime.Now;
p.Sum();
Console.WriteLine(DateTime.Now - time);

int x = 0;
time = DateTime.Now;
foreach(var item in p){
   x += item;
}
Console.WriteLine(DateTime.Now - time);

x = 0;
time = DateTime.Now;
for(int i = 0, j = f; i < j; ++i){
   x += p[i];
}
Console.WriteLine(DateTime.Now - time);

The same example for complex object is:

void Main()
{
    var f = 10000000;
    var p = new Test[f];

    for(int i = 0; i < f; ++i)
    {
        p[i] = new Test();
        p[i].Property = i % 2;
    }

    var time = DateTime.Now;
    p.Sum(k => k.Property);
    Console.WriteLine(DateTime.Now - time);

    int x = 0;
    time = DateTime.Now;
    foreach(var item in p){
        x += item.Property;
    }
    Console.WriteLine(DateTime.Now - time);

    x = 0;
    time = DateTime.Now;
    for(int i = 0, j = f; i < j; ++i){
        x += p[i].Property;
    }
    Console.WriteLine(DateTime.Now - time);
}

class Test
{
    public int Property { get; set; }
}

My results with compiler optimizations off are:

00:00:00.0570370 : Sum()
00:00:00.0250180 : Foreach()
00:00:00.0430272 : For(...)

and for second test are:

00:00:00.1450955 : Sum()
00:00:00.0650430 : Foreach()
00:00:00.0690510 : For()

it looks like LINQ is generally slower than foreach(...) but what is weird for me is that foreach(...) appears to be faster than for loop.

Python sum() function with list parameter

In the last answer, you don't need to make a list from numbers; it is already a list:

numbers = [1, 2, 3]
numsum = sum(numbers)
print(numsum)

How can I use SUM() OVER()

Seems like you expected the query to return running totals, but it must have given you the same values for both partitions of AccountID.

To obtain running totals with SUM() OVER (), you need to add an ORDER BY sub-clause after PARTITION BY …, like this:

SUM(Quantity) OVER (PARTITION BY AccountID ORDER BY ID)

But remember, not all database systems support ORDER BY in the OVER clause of a window aggregate function. (For instance, SQL Server didn't support it until the latest version, SQL Server 2012.)

How do I get SUM function in MySQL to return '0' if no values are found?

Use IFNULL or COALESCE:

SELECT IFNULL(SUM(Column1), 0) AS total FROM...

SELECT COALESCE(SUM(Column1), 0) AS total FROM...

The difference between them is that IFNULL is a MySQL extension that takes two arguments, and COALESCE is a standard SQL function that can take one or more arguments. When you only have two arguments using IFNULL is slightly faster, though here the difference is insignificant since it is only called once.

Finding moving average from data points in Python

There is a problem with the accepted answer. I think we need to use "valid" instead of "same" here - return numpy.convolve(interval, window, 'same') .

As an Example try out the MA of this data-set = [1,5,7,2,6,7,8,2,2,7,8,3,7,3,7,3,15,6] - the result should be [4.2,5.4,6.0,5.0,5.0,5.2,5.4,4.4,5.4,5.6,5.6,4.6,7.0,6.8], but having "same" gives us an incorrect output of [2.6,3.0,4.2,5.4,6.0,5.0,5.0,5.2,5.4,4.4,5.4,5.6,5.6, 4.6,7.0,6.8,6.2,4.8]

Rusty code to try this out -:

result=[]
dataset=[1,5,7,2,6,7,8,2,2,7,8,3,7,3,7,3,15,6]
window_size=5
for index in xrange(len(dataset)):
    if index <=len(dataset)-window_size :
        tmp=(dataset[index]+ dataset[index+1]+ dataset[index+2]+ dataset[index+3]+ dataset[index+4])/5.0
        result.append(tmp)
    else:
      pass

result==movingaverage(y, window_size) 

Try this with valid & same and see whether the math makes sense.

See also -: http://sentdex.com/sentiment-analysisbig-data-and-python-tutorials-algorithmic-trading/how-to-chart-stocks-and-forex-doing-your-own-financial-charting/calculate-simple-moving-average-sma-python/

Using GroupBy, Count and Sum in LINQ Lambda Expressions

        var q = from b in listOfBoxes
                group b by b.Owner into g
                select new
                           {
                               Owner = g.Key,
                               Boxes = g.Count(),
                               TotalWeight = g.Sum(item => item.Weight),
                               TotalVolume = g.Sum(item => item.Volume)
                           };

Python Pandas counting and summing specific conditions

You didn't mention the fancy indexing capabilities of dataframes, e.g.:

>>> df = pd.DataFrame({"class":[1,1,1,2,2], "value":[1,2,3,4,5]})
>>> df[df["class"]==1].sum()
class    3
value    6
dtype: int64
>>> df[df["class"]==1].sum()["value"]
6
>>> df[df["class"]==1].count()["value"]
3

You could replace df["class"]==1by another condition.

Pandas: sum DataFrame rows for given columns

Create a list of column names you want to add up.

df['total']=df.loc[:,list_name].sum(axis=1)

If you want the sum for certain rows, specify the rows using ':'

Sum all the elements java arraylist

I haven't tested it but it should work.

public double incassoMargherita()
{
    double sum = 0;
    for(int i = 0; i < m.size(); i++)
    {
        sum = sum + m.get(i);
    }
    return sum;
}

How to sum array of numbers in Ruby?

array.reduce(0, :+)

While equivalent to array.inject(0, :+), the term reduce is entering a more common vernacular with the rise of MapReduce programming models.

inject, reduce, fold, accumulate, and compress are all synonymous as a class of folding functions. I find consistency across your code base most important, but since various communities tend to prefer one word over another, it’s nonetheless useful to know the alternatives.

To emphasize the map-reduce verbiage, here’s a version that is a little bit more forgiving on what ends up in that array.

array.map(&:to_i).reduce(0, :+)

Some additional relevant reading:

Performing a query on a result from another query?

Note that your initial query is probably not returning what you want:

SELECT availables.bookdate AS Date, DATEDIFF(now(),availables.updated_at) as Age 
FROM availables INNER JOIN rooms ON availables.room_id=rooms.id 
WHERE availables.bookdate BETWEEN  '2009-06-25' AND date_add('2009-06-25', INTERVAL 4 DAY) AND rooms.hostel_id = 5094 GROUP BY availables.bookdate

You are grouping by book date, but you are not using any grouping function on the second column of your query.

The query you are probably looking for is:

SELECT availables.bookdate AS Date, count(*) as subtotal, sum(DATEDIFF(now(),availables.updated_at) as Age)
FROM availables INNER JOIN rooms ON availables.room_id=rooms.id
WHERE availables.bookdate BETWEEN '2009-06-25' AND date_add('2009-06-25', INTERVAL 4 DAY) AND rooms.hostel_id = 5094
GROUP BY availables.bookdate

Using SUMIFS with multiple AND OR conditions

Speed

SUMPRODUCT is faster than SUM arrays, i.e. having {} arrays in the SUM function. SUMIFS is 30% faster than SUMPRODUCT.

{SUM(SUMIFS({}))} vs SUMPRODUCT(SUMIFS({})) both works fine, but SUMPRODUCT feels a bit easier to write without the CTRL-SHIFT-ENTER to create the {}.

Preference

I personally prefer writing SUMPRODUCT(--(ISNUMBER(MATCH(...)))) over SUMPRODUCT(SUMIFS({})) for multiple criteria.

However, if you have a drop-down menu where you want to select specific characteristics or all, SUMPRODUCT(SUMIFS()), is the only way to go. (as for selecting "all", the value should enter in "<>" + "Whatever word you want as long as it's not part of the specific characteristics".

SUM of grouped COUNT in SQL Query

select sum(s) from (select count(Col_name) as s from Tab_name group by Col_name having count(*)>1)c

How to sum all column values in multi-dimensional array?

Another version, with some benefits below.

$sum = ArrayHelper::copyKeys($arr[0]);

foreach ($arr as $item) {
    ArrayHelper::addArrays($sum, $item);
}


class ArrayHelper {

    public function addArrays(Array &$to, Array $from) {
        foreach ($from as $key=>$value) {
            $to[$key] += $value;
        }
    }

    public function copyKeys(Array $from, $init=0) {
        return array_fill_keys(array_keys($from), $init);
    }

}

I wanted to combine the best of Gumbo's, Graviton's, and Chris J's answer with the following goals so I could use this in my app:

a) Initialize the 'sum' array keys outside of the loop (Gumbo). Should help with performance on very large arrays (not tested yet!). Eliminates notices.

b) Main logic is easy to understand without hitting the manuals. (Graviton, Chris J).

c) Solve the more general problem of adding the values of any two arrays with the same keys and make it less dependent on the sub-array structure.

Unlike Gumbo's solution, you could reuse this in cases where the values are not in sub arrays. Imagine in the example below that $arr1 and $arr2 are not hard-coded, but are being returned as the result of calling a function inside a loop.

$arr1 = array(
    'gozhi' => 2,
    'uzorong' => 1,
    'ngangla' => 4,
    'langthel' => 5
);

$arr2 = array(
   'gozhi' => 5,
   'uzorong' => 0,
   'ngangla' => 3,
   'langthel' => 2
);

$sum = ArrayHelper::copyKeys($arr1);

ArrayHelper::addArrays($sum, $arr1);
ArrayHelper::addArrays($sum, $arr2);

how to count the total number of lines in a text file using python

You can use sum() with a generator expression:

with open('data.txt') as f:
    print sum(1 for _ in f)

Note that you cannot use len(f), since f is an iterator. _ is a special variable name for throwaway variables, see What is the purpose of the single underscore "_" variable in Python?.

You can use len(f.readlines()), but this will create an additional list in memory, which won't even work on huge files that don't fit in memory.

Sum the digits of a number

I cam up with a recursive solution:

def sumDigits(num):
#   print "evaluating:", num
  if num < 10:
    return num

  # solution 1
#   res = num/10
#   rem = num%10
#   print "res:", res, "rem:", rem
#   return sumDigits(res+rem)

    # solution 2
  arr = [int(i) for i in str(num)]
  return sumDigits(sum(arr))

# print(sumDigits(1))
# print(sumDigits(49))
print(sumDigits(439230))
# print(sumDigits(439237))

Summing elements in a list

You can also use reduce method:

>>> myList = [3, 5, 4, 9]
>>> myTotal = reduce(lambda x,y: x+y, myList)
>>> myTotal
21

Furthermore, you can modify the lambda function to do other operations on your list.

Calculating the SUM of (Quantity*Price) from 2 different tables

i think this - including null value = 0

 SELECT oi.id, 
         SUM(nvl(oi.quantity,0) * nvl(p.price,0)) AS total_qty 
    FROM ORDERITEM oi 
    JOIN PRODUCT p ON p.id = oi.productid 
   WHERE oi.orderid = @OrderId 
GROUP BY oi.id 

SQL not a single-group group function

If you want downloads number for each customer, use:

select ssn
     , sum(time)
  from downloads
 group by ssn

If you want just one record -- for a customer with highest number of downloads -- use:

select *
  from (
        select ssn
             , sum(time)
          from downloads
         group by ssn
         order by sum(time) desc
       )
 where rownum = 1

However if you want to see all customers with the same number of downloads, which share the highest position, use:

select *
  from (
        select ssn
             , sum(time)
             , dense_rank() over (order by sum(time) desc) r
          from downloads
         group by ssn
       )
 where r = 1

Java method to sum any number of ints

public int sumAll(int... nums) { //var-args to let the caller pass an arbitrary number of int
    int sum = 0; //start with 0
    for(int n : nums) { //this won't execute if no argument is passed
        sum += n; // this will repeat for all the arguments
    }
    return sum; //return the sum
} 

Sum one number to every element in a list (or array) in Python

You can also use map:

a = [1, 1, 1, 1, 1]
b = 1
list(map(lambda x: x + b, a))

It gives:

[2, 2, 2, 2, 2]

MySql sum elements of a column

select
  sum(a) as atotal,
  sum(b) as btotal,
  sum(c) as ctotal
from
  yourtable t
where
  t.id in (1, 2, 3)

Sum of Numbers C++

You are just updating the value of i in the loop. The value of i should also be added each time.

It is never a good idea to update the value of i inside the for loop. The for loop index should only be used as a counter. In your case, changing the value of i inside the loop will cause all sorts of confusion.

Create variable total that holds the sum of the numbers up to i.

So

 for (int i = 0; i < positiveInteger; i++)
        total += i;

SQL Update to the SUM of its joined values

An alternate to the above solutions is using Aliases for Tables:

UPDATE T1 SET T1.extrasPrice = (SELECT SUM(T2.Price) FROM BookingPitchExtras T2 WHERE T2.pitchID = T1.ID)
FROM BookingPitches T1;

How to SUM parts of a column which have same text value in different column in the same row

If your data has the names grouped as shown then you can use this formula in D2 copied down to get a total against the last entry for each name

=IF((A2=A3)*(B2=B3),"",SUM(C$2:C2)-SUM(D$1:D1))

See screenshot

enter image description here

How do you find the sum of all the numbers in an array in Java?

 public class Num1
 {
     public static void main ()
     {
          //Declaration and Initialization
          int a[]={10,20,30,40,50}

          //To find the sum of array elements
          int sum=0;
          for(int i=0;i<a.length;i++)
          {
              sum=sum+i;
          }

          //To display the sum
          System.out.println("The sum is :"+sum);

     }
  } 

What are the ways to sum matrix elements in MATLAB?

For very large matrices using sum(sum(A)) can be faster than sum(A(:)):

>> A = rand(20000);
>> tic; B=sum(A(:)); toc; tic; C=sum(sum(A)); toc
Elapsed time is 0.407980 seconds.
Elapsed time is 0.322624 seconds.

How to find sum of several integers input by user using do/while, While statement or For statement

You should do:

#include<iostream>
using namespace std;
int main ()
{

    int sum = 0;
    int number;
    int numberitems;


    cout << "Enter number of items: \n";
    cin >> numberitems;

    for(int i=0;i<numberitems;i++)
    {
        cout << "Enter number <<i<<":" \n";
        cin >> number; sum+=number;
    }
    cout<<"sum is: "<< sum<<endl;
}

And with a while statement

#include <iostream>
using namespace std;
int main ()
{
    int sum = 0;
    int number;
    int numberitems;
    cin>>numberitems;

    cout << "Enter number: \n";

    while (count <=numberitems)
    {
        cin >> number;
        sum+=number;
    }
    cout << sum << endl;
}

Sum function in VBA

Range("A10") = WorksheetFunction.Sum(Worksheets("Sheet1").Range("A1", "A9"))

Where

Range("A10") is the answer cell

Range("A1", "A9") is the range to calculate

How to find the cumulative sum of numbers in a list?

In [42]: a = [4, 6, 12]

In [43]: [sum(a[:i+1]) for i in xrange(len(a))]
Out[43]: [4, 10, 22]

This is slighlty faster than the generator method above by @Ashwini for small lists

In [48]: %timeit list(accumu([4,6,12]))
  100000 loops, best of 3: 2.63 us per loop

In [49]: %timeit [sum(a[:i+1]) for i in xrange(len(a))]
  100000 loops, best of 3: 2.46 us per loop

For larger lists, the generator is the way to go for sure. . .

In [50]: a = range(1000)

In [51]: %timeit [sum(a[:i+1]) for i in xrange(len(a))]
  100 loops, best of 3: 6.04 ms per loop

In [52]: %timeit list(accumu(a))
  10000 loops, best of 3: 162 us per loop

How can I change NULL to 0 when getting a single value from a SQL function?

You can use ISNULL().

SELECT ISNULL(SUM(Price), 0) AS TotalPrice 
FROM Inventory
WHERE (DateAdded BETWEEN @StartDate AND @EndDate)

That should do the trick.

Add SUM of values of two LISTS into new LIST

From docs

import operator
list(map(operator.add, first,second))

Get total of Pandas column

Similar to getting the length of a dataframe, len(df), the following worked for pandas and blaze:

Total = sum(df['MyColumn'])

or alternatively

Total = sum(df.MyColumn)
print Total

Why does the 'int' object is not callable error occur when using the sum() function?

This means that somewhere else in your code, you have something like:

sum = 0

Which shadows the builtin sum (which is callable) with an int (which isn't).

Sum values from an array of key-value pairs in JavaScript

Try the following

_x000D_
_x000D_
var myData = [['2013-01-22', 0], ['2013-01-29', 1], ['2013-02-05', 21]];_x000D_
_x000D_
var myTotal = 0;  // Variable to hold your total_x000D_
_x000D_
for(var i = 0, len = myData.length; i < len; i++) {_x000D_
    myTotal += myData[i][1];  // Iterate over your first array and then grab the second element add the values up_x000D_
}_x000D_
_x000D_
document.write(myTotal); // 22 in this instance
_x000D_
_x000D_
_x000D_

How can I detect the encoding/codepage of a text file

Have you tried C# port for Mozilla Universal Charset Detector

Example from http://code.google.com/p/ude/

public static void Main(String[] args)
{
    string filename = args[0];
    using (FileStream fs = File.OpenRead(filename)) {
        Ude.CharsetDetector cdet = new Ude.CharsetDetector();
        cdet.Feed(fs);
        cdet.DataEnd();
        if (cdet.Charset != null) {
            Console.WriteLine("Charset: {0}, confidence: {1}", 
                 cdet.Charset, cdet.Confidence);
        } else {
            Console.WriteLine("Detection failed.");
        }
    }
}    

What is private bytes, virtual bytes, working set?

There is an interesting discussion here: http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/307d658a-f677-40f2-bdef-e6352b0bfe9e/ My understanding of this thread is that freeing small allocations are not reflected in Private Bytes or Working Set.

Long story short:

if I call

p=malloc(1000);
free(p);

then the Private Bytes reflect only the allocation, not the deallocation.

if I call

p=malloc(>512k);
free(p);

then the Private Bytes correctly reflect the allocation and the deallocation.

How do I change the formatting of numbers on an axis with ggplot?

I also found another way of doing this that gives proper 'x10(superscript)5' notation on the axes. I'm posting it here in the hope it might be useful to some. I got the code from here so I claim no credit for it, that rightly goes to Brian Diggs.

fancy_scientific <- function(l) {
     # turn in to character string in scientific notation
     l <- format(l, scientific = TRUE)
     # quote the part before the exponent to keep all the digits
     l <- gsub("^(.*)e", "'\\1'e", l)
     # turn the 'e+' into plotmath format
     l <- gsub("e", "%*%10^", l)
     # return this as an expression
     parse(text=l)
}

Which you can then use as

ggplot(data=df, aes(x=x, y=y)) +
   geom_point() +
   scale_y_continuous(labels=fancy_scientific) 

Lowercase and Uppercase with jQuery

If it's just for display purposes, you can render the text as upper or lower case in pure CSS, without any Javascript using the text-transform property:

.myclass {
    text-transform: lowercase;
}

See https://developer.mozilla.org/en/CSS/text-transform for more info.

However, note that this doesn't actually change the value to lower case; it just displays it that way. This means that if you examine the contents of the element (ie using Javascript), it will still be in its original format.

How to convert a list of numbers to jsonarray in Python

Use the json module to produce JSON output:

import json

with open(outputfilename, 'wb') as outfile:
    json.dump(row, outfile)

This writes the JSON result directly to the file (replacing any previous content if the file already existed).

If you need the JSON result string in Python itself, use json.dumps() (added s, for 'string'):

json_string = json.dumps(row)

The L is just Python syntax for a long integer value; the json library knows how to handle those values, no L will be written.

Demo string output:

>>> import json
>>> row = [1L,[0.1,0.2],[[1234L,1],[134L,2]]]
>>> json.dumps(row)
'[1, [0.1, 0.2], [[1234, 1], [134, 2]]]'

Excluding files/directories from Gulp task

Gulp uses micromatch under the hood for matching globs, so if you want to exclude any of the .min.js files, you can achieve the same by using an extended globbing feature like this:

src("'js/**/!(*.min).js")

Basically what it says is: grab everything at any level inside of js that doesn't end with *.min.js

How can I make a button have a rounded border in Swift?

You can subclass UIButton and add @IBInspectable variables to it so you can configure the custom button parameters via the StoryBoard "Attribute Inspector". Below I write down that code.

@IBDesignable
class BHButton: UIButton {

    /*
    // Only override draw() if you perform custom drawing.
    // An empty implementation adversely affects performance during animation.
    override func draw(_ rect: CGRect) {
        // Drawing code
    }
    */

    @IBInspectable lazy var isRoundRectButton : Bool = false

    @IBInspectable public var cornerRadius : CGFloat = 0.0 {
        didSet{
            setUpView()
        }
    }

    @IBInspectable public var borderColor : UIColor = UIColor.clear {
        didSet {
            self.layer.borderColor = borderColor.cgColor
        }
    }

    @IBInspectable public var borderWidth : CGFloat = 0.0 {
        didSet {
            self.layer.borderWidth = borderWidth
        }
    }

    //  MARK:   Awake From Nib

    override func awakeFromNib() {
        super.awakeFromNib()
        setUpView()
    }

    override func prepareForInterfaceBuilder() {
        super.prepareForInterfaceBuilder()
        setUpView()
    }

    func setUpView() {
        if isRoundRectButton {
            self.layer.cornerRadius = self.bounds.height/2;
            self.clipsToBounds = true
        }
        else{
            self.layer.cornerRadius = self.cornerRadius;
            self.clipsToBounds = true
        }
    }

}

Bootstrap 3 with remote Modal

I do it this way:

<!-- global template loaded in all pages // -->
     <div id="NewsModal" class="modal fade" tabindex="-1" role="dialog" data-ajaxload="true" aria-labelledby="newsLabel" aria-hidden="true">
            <div class="modal-dialog">
                <div class="modal-content">
                    <div class="modal-header">
                        <button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
                        <h3 class="newsLabel"></h3>
                    </div>
                    <div class="modal-body">
                            <div class="loading">
                                <span class="caption">Loading...</span>
                               <img src="/images/loading.gif" alt="loading">
                        </div>
                    </div>
                    <div class="modal-footer caption">
                        <button class="btn btn-right default modal-close" data-dismiss="modal">Close</button>
                    </div>
                </div>
            </div>
        </div>

Here is my a href:

<a href="#NewsModal" onclick="remote=\'modal_newsfeed.php?USER='.trim($USER).'&FUNCTION='.trim(urlencode($FUNCTIONCODE)).'&PATH_INSTANCE='.$PATH_INSTANCE.'&ALL=ALL\'
                                        remote_target=\'#NewsModal .modal-body\'" role="button" data-toggle="modal">See All Notifications <i class="m-icon-swapright m-icon-dark"></i></a>

Box-Shadow on the left side of the element only

This question is very, very, very old, but as a trick in the future, I recommend something like this:

.element{
    box-shadow: 0px 0px 10px #232931;
}
.container{
    height: 100px;
    width: 100px;
    overflow: hidden;
}

Basically, you have a box shadow and then wrapping the element in a div with its overflow set to hidden. You'll need to adjust the height, width, and even padding of the div to only show the left box shadow, but it works. See here for an example If you look at the example, you can see how there's no other shadows, but only a black left shadow. Edit: this is a retake of the same screen shot, in case some one thinks that I just cropped out the right. You can find it here

How to reset the use/password of jenkins on windows?

1 ) Copy the initialAdminPassword in Specified path.

2 ) Login with following Credentials

User Name : admin

Password : <da12906084fd405090a9fabfd66342f0> 

enter image description here

3 ) Once you login into the jenkins application you can click on admin profile and reset the password.

enter image description here

Simple working Example of json.net in VB.net

In Place of using this

MsgBox(json.SelectToken("Venue").SelectToken("ID"))

You can also use

MsgBox(json.SelectToken("Venue.ID"))

Getting the current Fragment instance in the viewpager

This is the simplest hack:

fun getCurrentFragment(): Fragment? {
    return if (count == 0) null
    else instantiateItem(view_pager, view_pager.currentItem) as? Fragment
}

(kotlin code)

Just call instantiateItem(viewPager, viewPager.getCurrentItem() and cast it to Fragment. Your item would already be instantiated. To be sure you can add a check for getCount.

Works with both FragmentPagerAdapter and FragmentStatePagerAdapter!

Could not commit JPA transaction: Transaction marked as rollbackOnly

Could not commit JPA transaction: Transaction marked as rollbackOnly

This exception occurs when you invoke nested methods/services also marked as @Transactional. JB Nizet explained the mechanism in detail. I'd like to add some scenarios when it happens as well as some ways to avoid it.

Suppose we have two Spring services: Service1 and Service2. From our program we call Service1.method1() which in turn calls Service2.method2():

class Service1 {
    @Transactional
    public void method1() {
        try {
            ...
            service2.method2();
            ...
        } catch (Exception e) {
            ...
        }
    }
}

class Service2 {
    @Transactional
    public void method2() {
        ...
        throw new SomeException();
        ...
    }
}

SomeException is unchecked (extends RuntimeException) unless stated otherwise.

Scenarios:

  1. Transaction marked for rollback by exception thrown out of method2. This is our default case explained by JB Nizet.

  2. Annotating method2 as @Transactional(readOnly = true) still marks transaction for rollback (exception thrown when exiting from method1).

  3. Annotating both method1 and method2 as @Transactional(readOnly = true) still marks transaction for rollback (exception thrown when exiting from method1).

  4. Annotating method2 with @Transactional(noRollbackFor = SomeException) prevents marking transaction for rollback (no exception thrown when exiting from method1).

  5. Suppose method2 belongs to Service1. Invoking it from method1 does not go through Spring's proxy, i.e. Spring is unaware of SomeException thrown out of method2. Transaction is not marked for rollback in this case.

  6. Suppose method2 is not annotated with @Transactional. Invoking it from method1 does go through Spring's proxy, but Spring pays no attention to exceptions thrown. Transaction is not marked for rollback in this case.

  7. Annotating method2 with @Transactional(propagation = Propagation.REQUIRES_NEW) makes method2 start new transaction. That second transaction is marked for rollback upon exit from method2 but original transaction is unaffected in this case (no exception thrown when exiting from method1).

  8. In case SomeException is checked (does not extend RuntimeException), Spring by default does not mark transaction for rollback when intercepting checked exceptions (no exception thrown when exiting from method1).

See all scenarios tested in this gist.

How can I output a UTF-8 CSV in PHP that Excel will read properly?

For me none of the solution above worked. Below is what i did to resolve the issue: modify the value using this function in the PHP code:

$value = utf8_encode($value);

This output values properly in an excel sheet.

How to check whether a variable is a class or not?

Even better: use the inspect.isclass function.

>>> import inspect
>>> class X(object):
...     pass
... 
>>> inspect.isclass(X)
True

>>> x = X()
>>> isinstance(x, X)
True
>>> y = 25
>>> isinstance(y, X)
False

vagrant primary box defined but commands still run against all boxes

The primary flag seems to only work for vagrant ssh for me.

In the past I have used the following method to hack around the issue.

# stage box intended for configuration closely matching production if ARGV[1] == 'stage'     config.vm.define "stage" do |stage|         box_setup stage, \         "10.9.8.31", "deploy/playbook_full_stack.yml", "deploy/hosts/vagrant_stage.yml"     end end 

How to return 2 values from a Java method?

You can only return one value in Java, so the neatest way is like this:

return new Pair<Integer>(number1, number2);

Here's an updated version of your code:

public class Scratch
{
    // Function code
    public static Pair<Integer> something() {
        int number1 = 1;
        int number2 = 2;
        return new Pair<Integer>(number1, number2);
    }

    // Main class code
    public static void main(String[] args) {
        Pair<Integer> pair = something();
        System.out.println(pair.first() + pair.second());
    }
}

class Pair<T> {
    private final T m_first;
    private final T m_second;

    public Pair(T first, T second) {
        m_first = first;
        m_second = second;
    }

    public T first() {
        return m_first;
    }

    public T second() {
        return m_second;
    }
}

Why are #ifndef and #define used in C++ header files?

They are called ifdef or include guards.

If writing a small program it might seems that it is not needed, but as the project grows you could intentionally or unintentionally include one file many times, which can result in compilation warning like variable already declared.

#ifndef checks whether HEADERFILE_H is not declared.
#define will declare HEADERFILE_H once #ifndef generates true.
#endif is to know the scope of #ifndef i.e end of #ifndef

If it is not declared which means #ifndef generates true then only the part between #ifndef and #endif executed otherwise not. This will prevent from again declaring the identifiers, enums, structure, etc...

How to make layout with rounded corners..?

For API 21+, Use Clip Views

Rounded outline clipping was added to the View class in API 21. See this training doc or this reference for more info.

This in-built feature makes rounded corners very easy to implement. It works on any view or layout and supports proper clipping.

Here's What To Do:

  • Create a rounded shape drawable and set it as your view's background: android:background="@drawable/round_outline"
  • Clip to outline in code: setClipToOutline(true)

The documentation used to say that you can set android:clipToOutline="true" the XML, but this bug is now finally resolved and the documentation now correctly states that you can only do this in code.

What It Looks Like:

examples with and without clipToOutline

Special Note About ImageViews

setClipToOutline() only works when the View's background is set to a shape drawable. If this background shape exists, View treats the background's outline as the borders for clipping and shadowing purposes.

This means that if you want to round the corners on an ImageView with setClipToOutline(), your image must come from android:src instead of android:background (since background is used for the rounded shape). If you MUST use background to set your image instead of src, you can use this nested views workaround:

  • Create an outer layout with its background set to your shape drawable
  • Wrap that layout around your ImageView (with no padding)
  • The ImageView (including anything else in the layout) will now be clipped to the outer layout's rounded shape.

What is the most efficient/elegant way to parse a flat table into a tree?

Well given the choice, I'd be using objects. I'd create an object for each record where each object has a children collection and store them all in an assoc array (/hashtable) where the Id is the key. And blitz through the collection once, adding the children to the relevant children fields. Simple.

But because you're being no fun by restricting use of some good OOP, I'd probably iterate based on:

function PrintLine(int pID, int level)
    foreach record where ParentID == pID
        print level*tabs + record-data
        PrintLine(record.ID, level + 1)

PrintLine(0, 0)

Edit: this is similar to a couple of other entries, but I think it's slightly cleaner. One thing I'll add: this is extremely SQL-intensive. It's nasty. If you have the choice, go the OOP route.

mysql_config not found when installing mysqldb python interface

sudo apt-get install python-mysqldb

Python 2.5? Sounds like you are using a very old version of Ubuntu Server (Hardy 8.04?) - please confirm which Linux version the server uses.

python-mysql search on ubuntu package database

Some additional info:

From the README of mysql-python -

Red Hat Linux .............

MySQL-python is pre-packaged in Red Hat Linux 7.x and newer. This includes Fedora Core and Red Hat Enterprise Linux. You can also build your own RPM packages as described above.

Debian GNU/Linux ................

Packaged as python-mysqldb_::

# apt-get install python-mysqldb

Or use Synaptic.

.. _python-mysqldb: http://packages.debian.org/python-mysqldb

Ubuntu ......

Same as with Debian.

Footnote: If you really are using a server distribution older than Ubuntu 10.04 then you are out of official support, and should upgrade sooner rather than later.

Convert SVG to PNG in Python

Here is what I did using cairosvg:

from cairosvg import svg2png

svg_code = """
    <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="#000" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
        <circle cx="12" cy="12" r="10"/>
        <line x1="12" y1="8" x2="12" y2="12"/>
        <line x1="12" y1="16" x2="12" y2="16"/>
    </svg>
"""

svg2png(bytestring=svg_code,write_to='output.png')

And it works like a charm!

See more: cairosvg document

#1055 - Expression of SELECT list is not in GROUP BY clause and contains nonaggregated column this is incompatible with sql_mode=only_full_group_by

Base ond defualt config of 5.7.5 ONLY_FULL_GROUP_BY You should use all the not aggregate column in your group by

select libelle,credit_initial,disponible_v,sum(montant) as montant 
FROM fiche,annee,type 
where type.id_type=annee.id_type 
and annee.id_annee=fiche.id_annee 
and annee = year(current_timestamp) 
GROUP BY libelle,credit_initial,disponible_v order by libelle asc

Uploading file using POST request in Node.js

 const remoteReq = request({
    method: 'POST',
    uri: 'http://host.com/api/upload',
    headers: {
      'Authorization': 'Bearer ' + req.query.token,
      'Content-Type': req.headers['content-type'] || 'multipart/form-data;'
    }
  })
  req.pipe(remoteReq);
  remoteReq.pipe(res);

Regex matching in a Bash if statement

In case someone wanted an example using variables...

#!/bin/bash

# Only continue for 'develop' or 'release/*' branches
BRANCH_REGEX="^(develop$|release//*)"

if [[ $BRANCH =~ $BRANCH_REGEX ]];
then
    echo "BRANCH '$BRANCH' matches BRANCH_REGEX '$BRANCH_REGEX'"
else
    echo "BRANCH '$BRANCH' DOES NOT MATCH BRANCH_REGEX '$BRANCH_REGEX'"
fi

How to format a number 0..9 to display with 2 digits (it's NOT a date)

You can use this:

NumberFormat formatter = new DecimalFormat("00");  
String s = formatter.format(1); // ----> 01

How can I list ALL grants a user received?

select distinct 'GRANT '||privilege||' ON '||OWNER||'.'||TABLE_NAME||' TO '||RP.GRANTEE
from DBA_ROLE_PRIVS RP join ROLE_TAB_PRIVS RTP 
on (RP.GRANTED_ROLE = RTP.role)  
where (OWNER in ('YOUR USER') --Change User Name
   OR RP.GRANTEE in ('YOUR USER')) --Change User Name
and RP.GRANTEE not in ('SYS', 'SYSTEM')
;

Is there a Newline constant defined in Java like Environment.Newline in C#?

As of Java 7 (and Android API level 19):

System.lineSeparator()

Documentation: Java Platform SE 7


For older versions of Java, use:

System.getProperty("line.separator");

See https://java.sun.com/docs/books/tutorial/essential/environment/sysprop.html for other properties.

Remove columns from dataframe where ALL values are NA

You can use Janitor package remove_empty

library(janitor)

df %>%
  remove_empty(c("rows", "cols")) #select either row or cols or both

Also, Another dplyr approach

 library(dplyr) 
 df %>% select_if(~all(!is.na(.)))

OR

df %>% select_if(colSums(!is.na(.)) == nrow(df))

this is also useful if you want to only exclude / keep column with certain number of missing values e.g.

 df %>% select_if(colSums(!is.na(.))>500)

Insert data using Entity Framework model

var context = new DatabaseEntities();

var t = new test //Make sure you have a table called test in DB
{
    ID = Guid.NewGuid(),
    name = "blah",
};

context.test.Add(t);
context.SaveChanges();

Should do it

Can regular expressions be used to match nested patterns?

Yes, if it is .NET RegEx-engine. .Net engine supports finite state machine supplied with an external stack. see details

how to send a post request with a web browser

You can create an html page with a form, having method="post" and action="yourdesiredurl" and open it with your browser.

As an alternative, there are some browser plugins for developers that allow you to do that, like Web Developer Toolbar for Firefox

How to set JAVA_HOME in Linux for all users

Probably a good idea to source whatever profile you edit to save having to use a fresh login.

either: source /etc/ or . /etc/

Where is whatever profile you edited.

How to open Console window in Eclipse?

the only solution for me was:

click on window->close all perspective (you can try also close perspective)

after this, in the top right corner click on: open perspective->resource

done

starting file download with JavaScript

I suggest to make an invisible iframe on the page and set it's src to url that you've received from the server - download will start without page reloading.

Or you can just set the current document.location.href to received url address. But that's can cause for user to see an error if the requested document actually does not exists.

Get an object attribute

Use getattr if you have an attribute in string form:

>>> class User(object):
       name = 'John'

>>> u = User()
>>> param = 'name'
>>> getattr(u, param)
'John'

Otherwise use the dot .:

>>> class User(object):
       name = 'John'

>>> u = User()
>>> u.name
'John'

How to Migrate to WKWebView?

Swift is not a requirement, everything works fine with Objective-C. UIWebView will continue to be supported, so there is no rush to migrate if you want to take your time. However, it will not get the javascript and scrolling performance enhancements of WKWebView.

For backwards compatibility, I have two properties for my view controller: a UIWebView and a WKWebView. I use the WKWebview only if the class exists:

if ([WKWebView class]) {
    // do new webview stuff
} else {
    // do old webview stuff
}

Whereas I used to have a UIWebViewDelegate, I also made it a WKNavigationDelegate and created the necessary methods.

Change SVN repository URL

Given that the Apache Subversion server will be moved to this new DNS alias: sub.someaddress.com.tr:

  • With Subversion 1.7 or higher, use svn relocate. Relocate is used when the SVN server's location changes. switch is only used if you want to change your local working copy to another branch or another path. If using TortoiseSVN, you may follow instructions from the TortoiseSVN Manual. If using the SVN command line interface, refer to this section of SVN's documentation. The command should look like this:

    svn relocate svn://sub.someaddress.com.tr/project

  • Keep using /project given that the actual contents of your repository probably won't change.

Note: svn relocate is not available before version 1.7 (thanks to ColinM for the info). In older versions you would use:

    svn switch --relocate OLD NEW

Finding the average of a list

Or use pandas's Series.mean method:

pd.Series(sequence).mean()

Demo:

>>> import pandas as pd
>>> l = [15, 18, 2, 36, 12, 78, 5, 6, 9]
>>> pd.Series(l).mean()
20.11111111111111
>>> 

From the docs:

Series.mean(axis=None, skipna=None, level=None, numeric_only=None, **kwargs)

And here is the docs for this:

https://pandas.pydata.org/pandas-docs/stable/generated/pandas.Series.mean.html

And the whole documentation:

https://pandas.pydata.org/pandas-docs/stable/10min.html

git-upload-pack: command not found, when cloning remote Git repo

You can also use the "-u" option to specify the path. I find this helpful on machines where my .bashrc doesn't get sourced in non-interactive sessions. For example,

git clone -u /home/you/bin/git-upload-pack you@machine:code

Getting an odd error, SQL Server query using `WITH` clause

In some cases this also occurs if you have table hints and you have spaces between WITH clause and your hint, so best to type it like:

SELECT Column1 FROM Table1 t1 WITH(NOLOCK)
INNER JOIN Table2 t2 WITH(NOLOCK) ON t1.Column1 = t2.Column1

And not:

SELECT Column1 FROM Table1 t1 WITH (NOLOCK)
INNER JOIN Table2 t2 WITH (NOLOCK) ON t1.Column1 = t2.Column1

Redirect using AngularJS

With an example of the not-working code, it will be easy to answer this question, but with this information the best that I can think is that you are calling the $location.path outside of the AngularJS digest.

Try doing this on the directive scope.$apply(function() { $location.path("/route"); });

What's sizeof(size_t) on 32-bit vs the various 64-bit data models?

EDIT: Thanks for the comments - I looked it up in the C99 standard, which says in section 6.5.3.4:

The value of the result is implementation-defined, and its type (an unsigned integer type) is size_t, defined in <stddef.h> (and other headers)

So, the size of size_t is not specified, only that it has to be an unsigned integer type. However, an interesting specification can be found in chapter 7.18.3 of the standard:

limit of size_t

SIZE_MAX 65535

Which basically means that, irrespective of the size of size_t, the allowed value range is from 0-65535, the rest is implementation dependent.

angular2 manually firing click event on particular element

Angular4

Instead of

    this.renderer.invokeElementMethod(
        this.fileInput.nativeElement, 'dispatchEvent', [event]);

use

    this.fileInput.nativeElement.dispatchEvent(event);

because invokeElementMethod won't be part of the renderer anymore.

Angular2

Use ViewChild with a template variable to get a reference to the file input, then use the Renderer to invoke dispatchEvent to fire the event:

import { Component, Renderer, ElementRef, ViewChild } from '@angular/core';
@Component({
  ...
  template: `
...
<input #fileInput type="file" id="imgFile" (click)="onChange($event)" >
...`
})
class MyComponent {
  @ViewChild('fileInput') fileInput:ElementRef;

  constructor(private renderer:Renderer) {}

  showImageBrowseDlg() {
    // from http://stackoverflow.com/a/32010791/217408
    let event = new MouseEvent('click', {bubbles: true});
    this.renderer.invokeElementMethod(
        this.fileInput.nativeElement, 'dispatchEvent', [event]);
  }
}

Update

Since direct DOM access isn't discouraged anymore by the Angular team this simpler code can be used as well

this.fileInput.nativeElement.click()

See also https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/dispatchEvent

Commit empty folder structure (with git)

According to their FAQ, GIT doesn't track empty directories.

Git FAQ

However, there are workarounds based on your needs and your project requirements.

Basically if you want to track an empty directory you can place a .gitkeep file in there. The file can be blank and it will just work. This is Gits way of tracking an empty directory.

Another option is to provide documentation for the directory. You can just add a readme file in it describing its expected usage. Git will track the folder because it has a file in it and you have now provided documentation to you and/or whoever else might be using the source code.

If you are building a web app you may find it useful to just add an index.html file which may contain a permission denied message if the folder is only accessible through the app. Codeigniter does this with all their directories.

How to center align the ActionBar title in Android?

The other tutorials I've seen override the whole action bar layout hiding the MenuItems. I've got it worked just doing the following steps:

Create a xml file as following:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <TextView
        android:id="@+id/title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:ellipsize="end"
        android:maxLines="1"
        android:text="@string/app_name"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:textColor="@android:color/white" />

</RelativeLayout>

And in the classe do it:

LayoutInflater inflator = (LayoutInflater) this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View v = inflator.inflate(R.layout.action_bar_title, null);

ActionBar.LayoutParams params = new ActionBar.LayoutParams(ActionBar.LayoutParams.WRAP_CONTENT, ActionBar.LayoutParams.MATCH_PARENT, Gravity.CENTER);

TextView titleTV = (TextView) v.findViewById(R.id.title);
titleTV.setText("Test");

get the value of input type file , and alert if empty

HTML Code

<input type="file" name="image" id="uploadImage" size="30" />
<input type="submit" name="upload"  class="send_upload" value="upload" />

jQuery Code using bind method

$(document).ready(function() {
    $('#upload').bind("click",function() 
    { if(!$('#uploadImage').val()){
                alert("empty");
                return false;} });  });

Transpose/Unzip Function (inverse of zip)?

Since it returns tuples (and can use tons of memory), the zip(*zipped) trick seems more clever than useful, to me.

Here's a function that will actually give you the inverse of zip.

def unzip(zipped):
    """Inverse of built-in zip function.
    Args:
        zipped: a list of tuples

    Returns:
        a tuple of lists

    Example:
        a = [1, 2, 3]
        b = [4, 5, 6]
        zipped = list(zip(a, b))

        assert zipped == [(1, 4), (2, 5), (3, 6)]

        unzipped = unzip(zipped)

        assert unzipped == ([1, 2, 3], [4, 5, 6])

    """

    unzipped = ()
    if len(zipped) == 0:
        return unzipped

    dim = len(zipped[0])

    for i in range(dim):
        unzipped = unzipped + ([tup[i] for tup in zipped], )

    return unzipped

Is there a "between" function in C#?

No, but you can write your own:

public static bool Between(this int num, int lower, int upper, bool inclusive = false)
{
    return inclusive
        ? lower <= num && num <= upper
        : lower < num && num < upper;
}

Convert date formats in bash

#since this was yesterday
date -dyesterday +%Y%m%d

#more precise, and more recommended
date -d'27 JUN 2011' +%Y%m%d

#assuming this is similar to yesterdays `date` question from you 
#http://stackoverflow.com/q/6497525/638649
date -d'last-monday' +%Y%m%d

#going on @seth's comment you could do this
DATE="27 jun 2011"; date -d"$DATE" +%Y%m%d

#or a method to read it from stdin
read -p "  Get date >> " DATE; printf "  AS YYYYMMDD format >> %s"  `date
-d"$DATE" +%Y%m%d`    

#which then outputs the following:
#Get date >> 27 june 2011   
#AS YYYYMMDD format >> 20110627

#if you really want to use awk
echo "27 june 2011" | awk '{print "date -d\""$1FS$2FS$3"\" +%Y%m%d"}' | bash

#note | bash just redirects awk's output to the shell to be executed
#FS is field separator, in this case you can use $0 to print the line
#But this is useful if you have more than one date on a line

More on Dates

note this only works on GNU date

I have read that:

Solaris version of date, which is unable to support -d can be resolve with replacing sunfreeware.com version of date

RegEx: How can I match all numbers greater than 49?

The fact that the first digit has to be in the range 5-9 only applies in case of two digits. So, check for that in the case of 2 digits, and allow any more digits directly:

^([5-9]\d|\d{3,})$

This regexp has beginning/ending anchors to make sure you're checking all digits, and the string actually represents a number. The | means "or", so either [5-9]\d or any number with 3 or more digits. \d is simply a shortcut for [0-9].

Edit: To disallow numbers like 001:

^([5-9]\d|[1-9]\d{2,})$

This forces the first digit to be not a zero in the case of 3 or more digits.

No process is on the other end of the pipe (SQL Server 2012)

Yup, this error might as well be "something failed, good luck figuring out what" - In my case it was a wrong username. SQL Server 2019 RC1.

Create dataframe from a matrix

I've found the following "cheat" to work very neatly and error-free

> dimnames <- list(time=c(0, 0.5, 1), name=c("C_0", "C_1"))
> mat <- matrix(data, ncol=2, nrow=3, dimnames=dimnames)
> head(mat, 2) #this returns the number of rows indicated in a data frame format
> df <- data.frame(head(mat, 2)) #"data.frame" might not be necessary

Et voila!

Xcode Product -> Archive disabled

In addition to the generic device (or "Any iOS Device" in newer versions of Xcode) mentioned in the other answers, it is possible that the "Archive" action is not selected for the current target in the scheme.

To view and edit at the current scheme, select Product > Schemes > Edit Scheme... (Cmd+<), then make sure that the "Archive" action is checked in the line corresponding to the desired target.

In the image below, Archive is not checked and the Archive action is greyed out in the Product menu. Checking the indicated checkbox fixed the issue for me.

scheme settings

How to enable back/left swipe gesture in UINavigationController after setting leftBarButtonItem?

This answer, but with storyboard support.

class SwipeNavigationController: UINavigationController {

    // MARK: - Lifecycle

    override init(rootViewController: UIViewController) {
        super.init(rootViewController: rootViewController)
    }

    override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
        super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)

        self.setup()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

        self.setup()
    }

    private func setup() {
        delegate = self
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        // This needs to be in here, not in init
        interactivePopGestureRecognizer?.delegate = self
    }

    deinit {
        delegate = nil
        interactivePopGestureRecognizer?.delegate = nil
    }

    // MARK: - Overrides

    override func pushViewController(_ viewController: UIViewController, animated: Bool) {
        duringPushAnimation = true

        super.pushViewController(viewController, animated: animated)
    }

    // MARK: - Private Properties

    fileprivate var duringPushAnimation = false
}

Get sum of MySQL column in PHP

$sql = "SELECT SUM(Value) FROM Codes";

$result = mysql_query($query);

while($row = mysql_fetch_array($result)){

    sum = $row['SUM(price)'];

}

echo sum;

In Tensorflow, get the names of all the Tensors in a graph

You can do

[n.name for n in tf.get_default_graph().as_graph_def().node]

Also, if you are prototyping in an IPython notebook, you can show the graph directly in notebook, see show_graph function in Alexander's Deep Dream notebook

What is the height of iPhone's onscreen keyboard?

iPhone

KeyboardSizes:

  1. 5S, SE, 5, 5C (320 × 568) keyboardSize = (0.0, 352.0, 320.0, 216.0) keyboardSize = (0.0, 315.0, 320.0, 253.0)

2.6S,6,7,8:(375 × 667) : keyboardSize = (0.0, 407.0, 375.0, 260.

3.6+,6S+, 7+ , 8+ : (414 × 736) keyboardSize = (0.0, 465.0, 414.0, 271.0)

4.XS, X :(375 X 812) keyboardSize = (0.0, 477.0, 375.0, 335.0)

5.XR,XSMAX((414 x 896) keyboardSize = (0.0, 550.0, 414.0, 346.0)

How do I calculate someone's age in Java?

Easiest way without any libraries:

    long today = new Date().getTime();
    long diff = today - birth;
    long age = diff / DateUtils.YEAR_IN_MILLIS;

Can I fade in a background image (CSS: background-image) with jQuery?

This is what worked for my, and its pure css


css

html {
    padding: 0;
    margin: 0;
    width: 100%;
    height: 100%;
  }

  body {
    padding: 0;
    margin: 0;
    width: 100%;
    height: 100%;
  }

  #bg {
    width: 100%;
    height: 100%;
    background: url('/image.jpg/') no-repeat center center fixed;

    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;

    -webkit-animation: myfirst 5s ; /* Chrome, Safari, Opera */
    animation: myfirst 5s ;
  }

  /* Chrome, Safari, Opera */
  @-webkit-keyframes myfirst {
    from {opacity: 0.2;}
    to {opacity: 1;}
  }

  /* Standard syntax */
  @keyframes myfirst {
    from {opacity: 0.2;}
    to {opacity: 1;}
  }

html

<!DOCTYPE html>
<html>
<head>
    <title></title>
</head>
<body>
  <div id="bg">
    <!-- content here -->
  </div> <!-- end bg -->
</body>
</html>

Setting DEBUG = False causes 500 Error

You must also check your URLs all over the place. When the DEBUG is set to False, all URLs without trailing / are treated as a bug, unlike when you have DEBUG = True, in which case Django will append / everywhere it is missing. So, in short, make sure all links end with a slash EVERYWHERE.

Byte[] to InputStream or OutputStream

You create and use byte array I/O streams as follows:

byte[] source = ...;
ByteArrayInputStream bis = new ByteArrayInputStream(source);
// read bytes from bis ...

ByteArrayOutputStream bos = new ByteArrayOutputStream();
// write bytes to bos ...
byte[] sink = bos.toByteArray();

Assuming that you are using a JDBC driver that implements the standard JDBC Blob interface (not all do), you can also connect a InputStream or OutputStream to a blob using the getBinaryStream and setBinaryStream methods1, and you can also get and set the bytes directly.

(In general, you should take appropriate steps to handle any exceptions, and close streams. However, closing bis and bos in the example above is unnecessary, since they aren't associated with any external resources; e.g. file descriptors, sockets, database connections.)

1 - The setBinaryStream method is really a getter. Go figure.

Sql select rows containing part of string

you can use CHARINDEX in t-sql.

select * from table where CHARINDEX(url, 'http://url.com/url?url...') > 0

MySQL SELECT AS combine two columns into one

If both columns can contain NULL, but you still want to merge them to a single string, the easiest solution is to use CONCAT_WS():

SELECT FirstName AS First_Name
     , LastName AS Last_Name
     , CONCAT_WS('', ContactPhoneAreaCode1, ContactPhoneNumber1) AS Contact_Phone 
  FROM TABLE1

This way you won't have to check for NULL-ness of each column separately.

Alternatively, if both columns are actually defined as NOT NULL, CONCAT() will be quite enough:

SELECT FirstName AS First_Name
     , LastName AS Last_Name
     , CONCAT(ContactPhoneAreaCode1, ContactPhoneNumber1) AS Contact_Phone 
  FROM TABLE1

As for COALESCE, it's a bit different beast: given the list of arguments, it returns the first that's not NULL.

How do you change the formatting options in Visual Studio Code?

Same thing happened to me just now. I set prettier as the Default Formatter in Settings and it started working again. My Default Formatter was null.

To set VSCODE Default Formatter

File -> Preferences -> Settings (for Windows) Code -> Preferences -> Settings (for Mac)

Search for "Default Formatter". In the dropdown, prettier will show as esbenp.prettier-vscode.

VSCODE Editor Option

.NET - Get protocol, host, and port

Well if you are doing this in Asp.Net or have access to HttpContext.Current.Request I'd say these are easier and more general ways of getting them:

var scheme = Request.Url.Scheme; // will get http, https, etc.
var host = Request.Url.Host; // will get www.mywebsite.com
var port = Request.Url.Port; // will get the port
var path = Request.Url.AbsolutePath; // should get the /pages/page1.aspx part, can't remember if it only get pages/page1.aspx

I hope this helps. :)

How to have css3 animation to loop forever

Whilst Elad's solution will work, you can also do it inline:

   -moz-animation: fadeinphoto 7s 20s infinite;
-webkit-animation: fadeinphoto 7s 20s infinite;
     -o-animation: fadeinphoto 7s 20s infinite;
        animation: fadeinphoto 7s 20s infinite;

Regex pattern including all special characters

Please don't do that... little Unicode BABY ANGELs like this one are dying! ??? (? these are not images) (nor is the arrow!)

?

And you are killing 20 years of DOS :-) (the last smiley is called WHITE SMILING FACE... Now it's at 263A... But in ancient times it was ALT-1)

and his friend

?

BLACK SMILING FACE... Now it's at 263B... But in ancient times it was ALT-2

Try a negative match:

Pattern regex = Pattern.compile("[^A-Za-z0-9]");

(this will ok only A-Z "standard" letters and "standard" 0-9 digits.)

Symbol for any number of any characters in regex?

Do you mean

.*

. any character, except newline character, with dotall mode it includes also the newline characters

* any amount of the preceding expression, including 0 times

Having a UITextField in a UITableViewCell

Try this out. Works like a charm for me (on iPhone devices). I used this code for a login screen once. I configured the table view to have two sections. You can of course get rid of the section conditionals.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:kCellIdentifier];
if (cell == nil) {
    cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault 
                                   reuseIdentifier:kCellIdentifier] autorelease];
    cell.accessoryType = UITableViewCellAccessoryNone;

    if ([indexPath section] == 0) {
        UITextField *playerTextField = [[UITextField alloc] initWithFrame:CGRectMake(110, 10, 185, 30)];
        playerTextField.adjustsFontSizeToFitWidth = YES;
        playerTextField.textColor = [UIColor blackColor];
        if ([indexPath row] == 0) {
            playerTextField.placeholder = @"[email protected]";
            playerTextField.keyboardType = UIKeyboardTypeEmailAddress;
            playerTextField.returnKeyType = UIReturnKeyNext;
        }
        else {
            playerTextField.placeholder = @"Required";
            playerTextField.keyboardType = UIKeyboardTypeDefault;
            playerTextField.returnKeyType = UIReturnKeyDone;
            playerTextField.secureTextEntry = YES;
        }       
        playerTextField.backgroundColor = [UIColor whiteColor];
        playerTextField.autocorrectionType = UITextAutocorrectionTypeNo; // no auto correction support
        playerTextField.autocapitalizationType = UITextAutocapitalizationTypeNone; // no auto capitalization support
        playerTextField.textAlignment = UITextAlignmentLeft;
        playerTextField.tag = 0;
        //playerTextField.delegate = self;

        playerTextField.clearButtonMode = UITextFieldViewModeNever; // no clear 'x' button to the right
        [playerTextField setEnabled: YES];

        [cell.contentView addSubview:playerTextField];

        [playerTextField release];
    }
}
if ([indexPath section] == 0) { // Email & Password Section
    if ([indexPath row] == 0) { // Email
        cell.textLabel.text = @"Email";
    }
    else {
        cell.textLabel.text = @"Password";
    }
}
else { // Login button section
    cell.textLabel.text = @"Log in";
}
return cell;    
}

Result looks like this:

login form

Displaying Image in Java

If you want to load/process/display images I suggest you use an image processing framework. Using Marvin, for instance, you can do that easily with just a few lines of source code.

Source code:

public class Example extends JFrame{

    MarvinImagePlugin prewitt           = MarvinPluginLoader.loadImagePlugin("org.marvinproject.image.edge.prewitt");
    MarvinImagePlugin errorDiffusion    = MarvinPluginLoader.loadImagePlugin("org.marvinproject.image.halftone.errorDiffusion");
    MarvinImagePlugin emboss            = MarvinPluginLoader.loadImagePlugin("org.marvinproject.image.color.emboss");

    public Example(){
        super("Example");

        // Layout
        setLayout(new GridLayout(2,2));

        // Load images
        MarvinImage img1 = MarvinImageIO.loadImage("./res/car.jpg");
        MarvinImage img2 = new MarvinImage(img1.getWidth(), img1.getHeight());
        MarvinImage img3 = new MarvinImage(img1.getWidth(), img1.getHeight());
        MarvinImage img4 = new MarvinImage(img1.getWidth(), img1.getHeight());

        // Image Processing plug-ins
        errorDiffusion.process(img1, img2);
        prewitt.process(img1, img3);
        emboss.process(img1, img4);

        // Set panels
        addPanel(img1);
        addPanel(img2);
        addPanel(img3);
        addPanel(img4);

        setSize(560,380);
        setVisible(true);
    }

    public void addPanel(MarvinImage image){
        MarvinImagePanel imagePanel = new MarvinImagePanel();
        imagePanel.setImage(image);
        add(imagePanel);
    }

    public static void main(String[] args) {
        new Example().setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

Output:

enter image description here

How to change the color of progressbar in C# .NET 3.5?

Simply right click on your project in Visual Basic Solution Explorer (where your vb files are) and select properties from the menu. In the window that pops up deselect "Enable XP Visual Styles" and now when you set forecolor, it should work now.

Why is my variable unaltered after I modify it inside of a function? - Asynchronous code reference

To state the obvious, the cup represents outerScopeVar.

Asynchronous functions be like...

asynchronous call for coffee

Replace words in a string - Ruby

First, you don't declare the type in Ruby, so you don't need the first string.

To replace a word in string, you do: sentence.gsub(/match/, "replacement").

How do I use .toLocaleTimeString() without displaying seconds?

The value returned by Date.prototype.toLocaleString is implementation dependent, so you get what you get. You can try to parse the string to remove seconds, but it may be different in different browsers so you'd need to make allowance for every browser in use.

Creating your own, unambiguous format isn't difficult using Date methods. For example:

function formatTimeHHMMA(d) {
  function z(n){return (n<10?'0':'')+n}
  var h = d.getHours();
  return (h%12 || 12) + ':' + z(d.getMinutes()) + ' ' + (h<12? 'AM' :'PM');
}

Radio button validation in javascript

document.forms[ 'forms1' ].onsubmit = function() {
    return [].some.call( this.elements, function( el ) {
        return el.type === 'radio' ? el.checked : false
    } )
}

Just something out of my head. Not sure the code is working.

What is the difference between putting a property on application.yml or bootstrap.yml in spring boot?

This answer has been very beautifully explained in book "Microservices Interview Questions, For Java Developers (Spring Boot, Spring Cloud, Cloud Native Applications) by Munish Chandel, Version 1.30, 25.03.2018.

The following content has been taken from this book, and total credit for this answer goes to the Author of the book i.e. Munish Chandel

application.yml

application.yml/application.properties file is specific to Spring Boot applications. Unless you change the location of external properties of an application, spring boot will always load application.yml from the following location:

/src/main/resources/application.yml

You can store all the external properties for your application in this file. Common properties that are available in any Spring Boot project can be found at: https://docs.spring.io/spring-boot/docs/current/reference/html/common-application-properties.html You can customize these properties as per your application needs. Sample file is shown below:

spring:
    application:
        name: foobar
    datasource:
        driverClassName: com.mysql.jdbc.Driver
        url: jdbc:mysql://localhost/test
server:
    port: 9000

bootstrap.yml

bootstrap.yml on the other hand is specific to spring-cloud-config and is loaded before the application.yml

bootstrap.yml is only needed if you are using Spring Cloud and your microservice configuration is stored on a remote Spring Cloud Config Server.

Important points about bootstrap.yml

  1. When used with Spring Cloud Config server, you shall specify the application-name and config git location using below properties.

spring.application.name: "application-name"
spring.cloud.config.server.git.uri: "git-uri-config"

  1. When used with microservices (other than cloud config server), we need to specify the application name and location of config server using below properties

spring.application.name: 
spring.cloud.config.uri: 
  1. This properties file can contain other configuration relevant to Spring Cloud environment for e.g. eureka server location, encryption/decryption related properties.

Upon startup, Spring Cloud makes an HTTP(S) call to the Spring Cloud Config Server with the name of the application and retrieves back that application’s configuration.

application.yml contains the default configuration for the microservice and any configuration retrieved (from cloud config server) during the bootstrap process will override configuration defined in application.yml

moment.js get current time in milliseconds?

See this link http://momentjs.com/docs/#/displaying/unix-timestamp-milliseconds/

valueOf() is the function you're looking for.

Editing my answer (OP wants milliseconds of today, not since epoch)

You want the milliseconds() function OR you could go the route of moment().valueOf()

Read file As String

this is working for me

i use this path

String FILENAME_PATH =  "/mnt/sdcard/Download/Version";

public static String getStringFromFile (String filePath) throws Exception {
    File fl = new File(filePath);
    FileInputStream fin = new FileInputStream(fl);
    String ret = convertStreamToString(fin);
    //Make sure you close all streams.
    fin.close();        
    return ret;

}

While variable is not defined - wait

Instead of using the windows load event use the ready event on the document.

$(document).ready(function(){[...]});

This should fire when everything in the DOM is ready to go, including media content fully loaded.

How to use HTTP GET in PowerShell?

In PowerShell v3, have a look at the Invoke-WebRequest and Invoke-RestMethod e.g.:

$msg = Read-Host -Prompt "Enter message"
$encmsg = [System.Web.HttpUtility]::UrlEncode($msg)
Invoke-WebRequest -Uri "http://smsserver/SNSManager/msgSend.jsp?uid&to=smartsms:*+001XXXXXX&msg=$encmsg&encoding=windows-1255"

Find empty or NaN entry in Pandas Dataframe

Check if the columns contain Nan using .isnull() and check for empty strings using .eq(''), then join the two together using the bitwise OR operator |.

Sum along axis 0 to find columns with missing data, then sum along axis 1 to the index locations for rows with missing data.

missing_cols, missing_rows = (
    (df2.isnull().sum(x) | df2.eq('').sum(x))
    .loc[lambda x: x.gt(0)].index
    for x in (0, 1)
)

>>> df2.loc[missing_rows, missing_cols]
         A2       A3
2            1.10035
5 -0.508501         
6       NaN      NaN
7       NaN      NaN

How can I remove leading and trailing quotes in SQL Server?

I thought this is a simpler script if you want to remove all quotes

UPDATE Table_Name
SET col_name = REPLACE(col_name, '"', '')

Logging levels - Logback - rule-of-thumb to assign log levels

This may also tangentially help, to understand if a logging request (from the code) at a certain level will result in it actually being logged given the effective logging level that a deployment is configured with. Decide what effective level you want to configure you deployment with from the other Answers here, and then refer to this to see if a particular logging request from your code will actually be logged then...

For examples:

  • "Will a logging code line that logs at WARN actually get logged on my deployment configured with ERROR?" The table says, NO.
  • "Will a logging code line that logs at WARN actually get logged on my deployment configured with DEBUG?" The table says, YES.

from logback documentation:

In a more graphic way, here is how the selection rule works. In the following table, the vertical header shows the level of the logging request, designated by p, while the horizontal header shows effective level of the logger, designated by q. The intersection of the rows (level request) and columns (effective level) is the boolean resulting from the basic selection rule. enter image description here

So a code line that requests logging will only actually get logged if the effective logging level of its deployment is less than or equal to that code line's requested level of severity.

How do I make a WPF TextBlock show my text on multiple lines?

This gets part way there. There is no ActualFontSize property but there is an ActualHeight and that would relate to the FontSize. Right now this only sizes for the original render. I could not figure out how to register the Converter as resize event. Actually maybe need to register the FontSize as a resize event. Please don't mark me down for an incomplete answer. I could not put code sample in a comment.

    <Window.Resources>
        <local:WidthConverter x:Key="widthConverter"/>
    </Window.Resources>
    <Grid>
        <Grid>
            <StackPanel VerticalAlignment="Center" Orientation="Vertical" >
                <Viewbox Margin="100,0,100,0">
                    <TextBlock x:Name="headerText" Text="Lorem ipsum dolor" Foreground="Black"/>
                </Viewbox>
                <TextBlock Margin="150,0,150,0" FontSize="{Binding ElementName=headerText, Path=ActualHeight, Converter={StaticResource widthConverter}}" x:Name="subHeaderText" Text="Lorem ipsum dolor, Lorem ipsum dolor, lorem isum dolor, Lorem ipsum dolor, Lorem ipsum dolor, lorem isum dolor, " TextWrapping="Wrap" Foreground="Gray" />
            </StackPanel>
        </Grid>
    </Grid>        

Converter

    [ValueConversion(typeof(double), typeof(double))]
    public class WidthConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            double width = (double)value*.7;
            return width; // columnsCount;
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    } 

How to split a string into an array in Bash?

t="one,two,three"
a=($(echo "$t" | tr ',' '\n'))
echo "${a[2]}"

Prints three

In Python script, how do I set PYTHONPATH?

PYTHONPATH ends up in sys.path, which you can modify at runtime.

import sys
sys.path += ["whatever"]

Where does R store packages?

Thanks for the direction from the above two answerers. James Thompson's suggestion worked best for Windows users.

  1. Go to where your R program is installed. This is referred to as R_Home in the literature. Once you find it, go to the /etc subdirectory.

    C:\R\R-2.10.1\etc
    
  2. Select the file in this folder named Rprofile.site. I open it with VIM. You will find this is a bare-bones file with less than 20 lines of code. I inserted the following inside the code:

    # my custom library path
    .libPaths("C:/R/library")
    

    (The comment added to keep track of what I did to the file.)

  3. In R, typing the .libPaths() function yields the first target at C:/R/Library

NOTE: there is likely more than one way to achieve this, but other methods I tried didn't work for some reason.

How do I control how Emacs makes backup files?

Emacs backup/auto-save files can be very helpful. But these features are confusing.

Backup files

Backup files have tildes (~ or ~9~) at the end and shall be written to the user home directory. When make-backup-files is non-nil Emacs automatically creates a backup of the original file the first time the file is saved from a buffer. If you're editing a new file Emacs will create a backup the second time you save the file.

No matter how many times you save the file the backup remains unchanged. If you kill the buffer and then visit the file again, or the next time you start a new Emacs session, a new backup file will be made. The new backup reflects the file's content after reopened, or at the start of editing sessions. But an existing backup is never touched again. Therefore I find it useful to created numbered backups (see the configuration below).

To create backups explicitly use save-buffer (C-x C-s) with prefix arguments.

diff-backup and dired-diff-backup compares a file with its backup or vice versa. But there is no function to restore backup files. For example, under Windows, to restore a backup file

C:\Users\USERNAME\.emacs.d\backups\!drive_c!Users!USERNAME!.emacs.el.~7~

it has to be manually copied as

C:\Users\USERNAME\.emacs.el

Auto-save files

Auto-save files use hashmarks (#) and shall be written locally within the project directory (along with the actual files). The reason is that auto-save files are just temporary files that Emacs creates until a file is saved again (like with hurrying obedience).

  • Before the user presses C-x C-s (save-buffer) to save a file Emacs auto-saves files - based on counting keystrokes (auto-save-interval) or when you stop typing (auto-save-timeout).
  • Emacs also auto-saves whenever it crashes, including killing the Emacs job with a shell command.

When the user saves the file, the auto-saved version is deleted. But when the user exits the file without saving it, Emacs or the X session crashes, the auto-saved files still exist.

Use revert-buffer or recover-file to restore auto-save files. Note that Emacs records interrupted sessions for later recovery in files named ~/.emacs.d/auto-save-list. The recover-session function will use this information.

The preferred method to recover from an auto-saved filed is M-x revert-buffer RET. Emacs will ask either "Buffer has been auto-saved recently. Revert from auto-save file?" or "Revert buffer from file FILENAME?". In case of the latter there is no auto-save file. For example, because you have saved before typing another auto-save-intervall keystrokes, in which case Emacs had deleted the auto-save file.

Auto-save is nowadays disabled by default because it can slow down editing when connected to a slow machine, and because many files contain sensitive data.

Configuration

Here is a configuration that IMHO works best:

(defvar --backup-directory (concat user-emacs-directory "backups"))
(if (not (file-exists-p --backup-directory))
        (make-directory --backup-directory t))
(setq backup-directory-alist `(("." . ,--backup-directory)))
(setq make-backup-files t               ; backup of a file the first time it is saved.
      backup-by-copying t               ; don't clobber symlinks
      version-control t                 ; version numbers for backup files
      delete-old-versions t             ; delete excess backup files silently
      delete-by-moving-to-trash t
      kept-old-versions 6               ; oldest versions to keep when a new numbered backup is made (default: 2)
      kept-new-versions 9               ; newest versions to keep when a new numbered backup is made (default: 2)
      auto-save-default t               ; auto-save every buffer that visits a file
      auto-save-timeout 20              ; number of seconds idle time before auto-save (default: 30)
      auto-save-interval 200            ; number of keystrokes between auto-saves (default: 300)
      )

Sensitive data

Another problem is that you don't want to have Emacs spread copies of files with sensitive data. Use this mode on a per-file basis. As this is a minor mode, for my purposes I renamed it sensitive-minor-mode.

To enable it for all .vcf and .gpg files, in your .emacs use something like:

(setq auto-mode-alist
      (append
       (list
        '("\\.\\(vcf\\|gpg\\)$" . sensitive-minor-mode)
        )
       auto-mode-alist))

Alternatively, to protect only some files, like some .txt files, use a line like

// -*-mode:asciidoc; mode:sensitive-minor; fill-column:132-*-

in the file.

What is the difference between ELF files and bin files?

A Bin file is a pure binary file with no memory fix-ups or relocations, more than likely it has explicit instructions to be loaded at a specific memory address. Whereas....

ELF files are Executable Linkable Format which consists of a symbol look-ups and relocatable table, that is, it can be loaded at any memory address by the kernel and automatically, all symbols used, are adjusted to the offset from that memory address where it was loaded into. Usually ELF files have a number of sections, such as 'data', 'text', 'bss', to name but a few...it is within those sections where the run-time can calculate where to adjust the symbol's memory references dynamically at run-time.

Fatal error: Uncaught Error: Call to undefined function mysql_connect()

mysql_* functions have been removed in PHP 7.

You probably have PHP 7 in XAMPP. You now have two alternatives: MySQLi and PDO.

Additionally, here is a nice wiki page about PDO.

Error: Jump to case label

C++11 standard on jumping over some initializations

JohannesD gave an explanation, now for the standards.

The C++11 N3337 standard draft 6.7 "Declaration statement" says:

3 It is possible to transfer into a block, but not in a way that bypasses declarations with initialization. A program that jumps (87) from a point where a variable with automatic storage duration is not in scope to a point where it is in scope is ill-formed unless the variable has scalar type, class type with a trivial default constructor and a trivial destructor, a cv-qualified version of one of these types, or an array of one of the preceding types and is declared without an initializer (8.5).

87) The transfer from the condition of a switch statement to a case label is considered a jump in this respect.

[ Example:

void f() {
   // ...
  goto lx;    // ill-formed: jump into scope of a
  // ...
ly:
  X a = 1;
  // ...
lx:
  goto ly;    // OK, jump implies destructor
              // call for a followed by construction
              // again immediately following label ly
}

— end example ]

As of GCC 5.2, the error message now says:

crosses initialization of

C

C allows it: c99 goto past initialization

The C99 N1256 standard draft Annex I "Common warnings" says:

2 A block with initialization of an object that has automatic storage duration is jumped into

How to call a SOAP web service on Android

For me the easiest way is to use good tool to generate all required classes. Personally I use this site:

http://easywsdl.com/

It supports quite complex web services and uses ksoap2.

What is the documents directory (NSDocumentDirectory)?

You can access documents directory using this code it is basically used for storing file in plist format:

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths firstObject];
return documentsDirectory;

What do &lt; and &gt; stand for?

In HTML, the less-than sign is used at the beginning of tags. if you use this bracket "<test1>" in content, your bracket content will be unvisible, html renderer is assuming it as a html tag, changing chars with it's ASCI numbers prevents the issue.

with html friendly name:

  &lt;test1&gt; 

or with asci number:

 &#60;test1&#62;

or comple asci:

&#60;&#116;&#101;&#115;&#116;&#49;&#62;

result: <test1>

asci referance: https://www.w3schools.com/charsets/ref_html_ascii.asp

What is the difference between String and StringBuffer in Java?

String is immutable, meaning that when you perform an operation on a String you are really creating a whole new String.

StringBuffer is mutable, and you can append to it as well as reset its length to 0.

In practice, the compiler seems to use StringBuffer during String concatenation for performance reasons.

Newline in JLabel

You can try and do this:

myLabel.setText("<html>" + myString.replaceAll("<","&lt;").replaceAll(">", "&gt;").replaceAll("\n", "<br/>") + "</html>")

The advantages of doing this are:

  • It replaces all newlines with <br/>, without fail.
  • It automatically replaces eventual < and > with &lt; and &gt; respectively, preventing some render havoc.

What it does is:

  • "<html>" + adds an opening html tag at the beginning
  • .replaceAll("<", "&lt;").replaceAll(">", "&gt;") escapes < and > for convenience
  • .replaceAll("\n", "<br/>") replaces all newlines by br (HTML line break) tags for what you wanted
  • ... and + "</html>" closes our html tag at the end.

P.S.: I'm very sorry to wake up such an old post, but whatever, you have a reliable snippet for your Java!

Your password does not satisfy the current policy requirements

NOTE: This might not be a secure solution. But if you are working on a test environment, just need a quick fix and doesn't even care about the security settings. This is a quick solution.

The same issue happened to me when I ran "mysql_secure_installation" and modified password security level to 'medium'.

I bypassed the error by running the followings:

mysql -h localhost -u root -p
mysql>uninstall plugin validate_password;

make sure you reinstall the plugin "validate_password" if necessary.

Qt: resizing a QLabel containing a QPixmap while keeping its aspect ratio

I have polished this missing subclass of QLabel. It is awesome and works well.

aspectratiopixmaplabel.h

#ifndef ASPECTRATIOPIXMAPLABEL_H
#define ASPECTRATIOPIXMAPLABEL_H

#include <QLabel>
#include <QPixmap>
#include <QResizeEvent>

class AspectRatioPixmapLabel : public QLabel
{
    Q_OBJECT
public:
    explicit AspectRatioPixmapLabel(QWidget *parent = 0);
    virtual int heightForWidth( int width ) const;
    virtual QSize sizeHint() const;
    QPixmap scaledPixmap() const;
public slots:
    void setPixmap ( const QPixmap & );
    void resizeEvent(QResizeEvent *);
private:
    QPixmap pix;
};

#endif // ASPECTRATIOPIXMAPLABEL_H

aspectratiopixmaplabel.cpp

#include "aspectratiopixmaplabel.h"
//#include <QDebug>

AspectRatioPixmapLabel::AspectRatioPixmapLabel(QWidget *parent) :
    QLabel(parent)
{
    this->setMinimumSize(1,1);
    setScaledContents(false);
}

void AspectRatioPixmapLabel::setPixmap ( const QPixmap & p)
{
    pix = p;
    QLabel::setPixmap(scaledPixmap());
}

int AspectRatioPixmapLabel::heightForWidth( int width ) const
{
    return pix.isNull() ? this->height() : ((qreal)pix.height()*width)/pix.width();
}

QSize AspectRatioPixmapLabel::sizeHint() const
{
    int w = this->width();
    return QSize( w, heightForWidth(w) );
}

QPixmap AspectRatioPixmapLabel::scaledPixmap() const
{
    return pix.scaled(this->size(), Qt::KeepAspectRatio, Qt::SmoothTransformation);
}

void AspectRatioPixmapLabel::resizeEvent(QResizeEvent * e)
{
    if(!pix.isNull())
        QLabel::setPixmap(scaledPixmap());
}

Hope that helps! (Updated resizeEvent, per @dmzl's answer)

How to render a DateTime in a specific format in ASP.NET MVC 3?

@{
  string datein = Convert.ToDateTime(item.InDate).ToString("dd/MM/yyyy");        
  @datein
}

Printing without newline (print 'a',) prints a space, how to remove?

as simple as that

def printSleeping():
     sleep = "I'm sleeping"
     v = ""
     for i in sleep:
         v += i
         system('cls')
         print v
         time.sleep(0.02)

How to include another XHTML in XHTML using JSF 2.0 Facelets?

Included page:

<!-- opening and closing tags of included page -->
<ui:composition ...>
</ui:composition>

Including page:

<!--the inclusion line in the including page with the content-->
<ui:include src="yourFile.xhtml"/>
  • You start your included xhtml file with ui:composition as shown above.
  • You include that file with ui:include in the including xhtml file as also shown above.

How to AUTO_INCREMENT in db2?

You will have to create an auto-increment field with the sequence object (this object generates a number sequence).

Use the following CREATE SEQUENCE syntax:

  CREATE SEQUENCE seq_person
  MINVALUE 1
  START WITH 1
  INCREMENT BY 1
  CACHE 10

The code above creates a sequence object called seq_person, that starts with 1 and will increment by 1. It will also cache up to 10 values for performance. The cache option specifies how many sequence values will be stored in memory for faster access.

To insert a new record into the "Persons" table, we will have to use the nextval function (this function retrieves the next value from seq_person sequence):

  INSERT INTO Persons (P_Id,FirstName,LastName)
  VALUES (seq_person.nextval,'Lars','Monsen')

The SQL statement above would insert a new record into the "Persons" table. The "P_Id" column would be assigned the next number from the seq_person sequence. The "FirstName" column would be set to "Lars" and the "LastName" column would be set to "Monsen".

Revert a jQuery draggable object back to its original container on out event of droppable

$(function() {
    $("#draggable").draggable({
        revert : function(event, ui) {
            // on older version of jQuery use "draggable"
            // $(this).data("draggable")
            // on 2.x versions of jQuery use "ui-draggable"
            // $(this).data("ui-draggable")
            $(this).data("uiDraggable").originalPosition = {
                top : 0,
                left : 0
            };
            // return boolean
            return !event;
            // that evaluate like this:
            // return event !== false ? false : true;
        }
    });
    $("#droppable").droppable();
});

Read from database and fill DataTable

Private Function LoaderData(ByVal strSql As String) As DataTable
    Dim cnn As SqlConnection
    Dim dad As SqlDataAdapter

    Dim dtb As New DataTable
    cnn = New SqlConnection(My.Settings.mySqlConnectionString)
    Try
        cnn.Open()
        dad = New SqlDataAdapter(strSql, cnn)
        dad.Fill(dtb)
        cnn.Close()
        dad.Dispose()
    Catch ex As Exception
        cnn.Close()
        MsgBox(ex.Message)
    End Try
    Return dtb
End Function

UITableView set to static cells. Is it possible to hide some of the cells programmatically?

In addition to @Saleh Masum solution:

If you get auto-layout errors, you can just remove the constraints from the tableViewCell.contentView

Swift 3:

override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
    let tableViewCell = super.tableView(tableView, cellForRowAt: indexPath)

    if tableViewCell.isHidden == true
    {
        tableViewCell.contentView.removeConstraints(tableViewCell.contentView.constraints)
        return 0
    }
    else{
        return super.tableView(tableView, heightForRowAt: indexPath)
    }

}

This solution depends on the flow of your app. If you want to show/hide the cell in the same view controller instance this may not be the best choice, because it removes the constraints.

Error when testing on iOS simulator: Couldn't register with the bootstrap server

Restarted the Device, Worked! :D

Thanks Everyone for the great suggestions.

Variable might not have been initialized error

because of your a and b variable is not have been initialized. You must initialized this variables for excample if you declare this variable like this int a=0; int b=0; than your code run without error.

Save Screen (program) output to a file

The following might be useful (tested on: Linux/Ubuntu 12.04 (Precise Pangolin)):

cat /dev/ttyUSB0

Using the above, you can then do all the re-directions that you need. For example, to dump output to your console while saving to your file, you'd do:

cat /dev/ttyUSB0 | tee console.log

Which is faster: Stack allocation or Heap allocation

You can write a special heap allocator for specific sizes of objects that is very performant. However, the general heap allocator is not particularly performant.

Also I agree with Torbjörn Gyllebring about the expected lifetime of objects. Good point!

HTML form with two submit buttons and two "target" attributes

HTML:

<form method="get">
<input type="text" name="id" value="123"/>
<input type="submit" name="action" value="add"/>
<input type="submit" name="action" value="delete"/>
</form>

JS:

$('form').submit(function(ev){ 
ev.preventDefault();
console.log('clicked',ev.originalEvent,ev.originalEvent.explicitOriginalTarget) 
})

http://jsfiddle.net/arzo/unhc3/

deleting folder from java

I wrote a method for this sometime back. It deletes the specified directory and returns true if the directory deletion was successful.

/**
 * Delets a dir recursively deleting anything inside it.
 * @param dir The dir to delete
 * @return true if the dir was successfully deleted
 */
public static boolean deleteDirectory(File dir) {
    if(! dir.exists() || !dir.isDirectory())    {
        return false;
    }

    String[] files = dir.list();
    for(int i = 0, len = files.length; i < len; i++)    {
        File f = new File(dir, files[i]);
        if(f.isDirectory()) {
            deleteDirectory(f);
        }else   {
            f.delete();
        }
    }
    return dir.delete();
}

SQL Server - copy stored procedures from one db to another

You can generate scriptof the stored proc's as depicted in other answers. Once the script have been generated, you can use sqlcmd to execute them against target DB like

sqlcmd -S <server name> -U <user name> -d <DB name> -i <script file> -o <output log file> 

How can I check if an InputStream is empty without reading from it?

If the InputStream you're using supports mark/reset support, you could also attempt to read the first byte of the stream and then reset it to its original position:

input.mark(1);
final int bytesRead = input.read(new byte[1]);
input.reset();
if (bytesRead != -1) {
    //stream not empty
} else {
    //stream empty
} 

If you don't control what kind of InputStream you're using, you can use the markSupported() method to check whether mark/reset will work on the stream, and fall back to the available() method or the java.io.PushbackInputStream method otherwise.

How can I remove "\r\n" from a string in C#? Can I use a regular expression?

Nicer code for this:

yourstring = yourstring.Replace(System.Environment.NewLine, string.Empty);

Change Tomcat Server's timeout in Eclipse

  1. Go to server View
  2. Double click the server for which you want to change the time limit
  3. On the right hand side you have timeouts dropdown tab. Select that.
  4. You then have option to change the time limits.

enter image description here

How to update RecyclerView Adapter Data?

This is what worked for me:

recyclerView.setAdapter(new RecyclerViewAdapter(newList));
recyclerView.invalidate();

After creating a new adapter that contains the updated list (in my case it was a database converted into an ArrayList) and setting that as adapter, I tried recyclerView.invalidate() and it worked.

npm install error from the terminal

I came across this, and my issue was using an older version of node (3.X), when a newer version was required.

The error message actually suggested this as well:

...
Make sure you have the latest version of node.js and npm installed
...

So the solution may be as simple as upgrading node/npm. You can easily do this using nvm, the "Node Version Manager"

After you've installed nvm, you can install and use the latest version of node by simply running this command:

nvm install node

For example:

$ nvm install node                                                             
Downloading https://nodejs.org/dist/v8.2.1/node-v8.2.1-darwin-x64.tar.xz...
######################################################################## 100.0%
Now using node v8.2.1 (npm v5.3.0)

$ node --version                                                               
v8.2.1

HTTP Error 404.3-Not Found in IIS 7.5

You should install IIS sub components from

Control Panel -> Programs and Features -> Turn Windows features on or off

Internet Information Services has subsection World Wide Web Services / Application Development Features

There you must check ASP.NET (.NET Extensibility, ISAPI Extensions, ISAPI Filters will be selected automatically). Double check that specific versions are checked. Under Windows Server 2012 R2, these options are split into 4 & 4.5.

Run from cmd:

%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -ir

Finally check in IIS manager, that your application uses application pool with .NET framework version v4.0.

Also, look at this answer.

Applying styles to tables with Twitter Bootstrap

bootstrap provides various classes for table

 <table class="table"></table>
 <table class="table table-bordered"></table>
 <table class="table table-hover"></table>
 <table class="table table-condensed"></table>
 <table class="table table-responsive"></table>

How to transition to a new view controller with code only using Swift

In Swift 2.0 you can use this method:

    let registrationView = LMRegistration()
    self.presentViewController(registrationView, animated: true, completion: nil)

How to get 0-padded binary representation of an integer in java?

I do not know "right" solution but I can suggest you a fast patch.

String.format("%16s", Integer.toBinaryString(1)).replace(" ", "0");

I have just tried it and saw that it works fine.

SQL JOIN, GROUP BY on three tables to get totals

I am not sure I got you but this might be what you are looking for:

SELECT i.invoiceid, sum(case when i.amount is not null then i.amount else 0 end), sum(case when i.amount is not null then i.amount else 0 end) - sum(case when p.amount is not null then p.amount else 0 end) AS amountdue
FROM invoices i
LEFT JOIN invoicepayments ip ON i.invoiceid = ip.invoiceid
LEFT JOIN payments p ON ip.paymentid = p.paymentid
LEFT JOIN customers c ON p.customerid = c.customerid
WHERE c.customernumber = '100'
GROUP BY i.invoiceid

This would get you the amounts sums in case there are multiple payment rows for each invoice

Change default global installation directory for node.js modules in Windows?

I tried most of the answers here nothing seems to work in my case. So i changed the Temp location in my env variables to C:\npm. Then it started to work. This is not a good idea but a temporary solution.

How to install python developer package?

If you use yum search you can find the python dev package for your version of python.

For me I was using python 3.5. I ran the following

yum search python | grep devel

Which returned the following

enter image description here

I was then able to install the correct package for my version of python with the following cmd.

sudo yum install python35u-devel.x86_64

This works on centos for ubuntu or debian you would need to use apt-get

jQuery selector for id starts with specific text

Let me offer a more extensive answer considering things that you haven't mentioned as yet but will find useful.

For your current problem the answer is

$("div[id^='editDialog']");

The caret (^) is taken from regular expressions and means starts with.

Solution 1

// Select elems where 'attribute' ends with 'Dialog'
$("[attribute$='Dialog']"); 

// Selects all divs where attribute is NOT equal to value    
$("div[attribute!='value']"); 

// Select all elements that have an attribute whose value is like
$("[attribute*='value']"); 

// Select all elements that have an attribute whose value has the word foobar
$("[attribute~='foobar']"); 

// Select all elements that have an attribute whose value starts with 'foo' and ends
//  with 'bar'
$("[attribute^='foo'][attribute$='bar']");

attribute in the code above can be changed to any attribute that an element may have, such as href, name, id or src.

Solution 2

Use classes

// Matches all items that have the class 'classname'
$(".className");

// Matches all divs that have the class 'classname'
$("div.className");

Solution 3

List them (also noted in previous answers)

$("#id1,#id2,#id3");

Solution 4

For when you improve, regular expression (Never actually used these, solution one has always been sufficient, but you never know!

// Matches all elements whose id takes the form editDialog-{one_or_more_integers}
$('div').filter(function () {this.id.match(/editDialog\-\d+/)});

How do I concatenate strings and variables in PowerShell?

You can also use -join

E.g.

$var = -join("Hello", " ", "world");

Would assign "Hello world" to $var.

So to output, in one line:

Write-Host (-join("Hello", " ", "world"))

How can I check whether a variable is defined in Node.js?

For easy tasks I often simply do it like:

var undef;

// Fails on undefined variables
if (query !== undef) {
    // variable is defined
} else {
    // else do this
}

Or if you simply want to check for a nulled value too..

var undef;

// Fails on undefined variables
// And even fails on null values
if (query != undef) {
    // variable is defined and not null
} else {
    // else do this
}

How to add 10 minutes to my (String) time?

I would use Joda Time, parse the time as a LocalTime, and then use

time = time.plusMinutes(10);

Short but complete program to demonstrate this:

import org.joda.time.*;
import org.joda.time.format.*;

public class Test {
    public static void main(String[] args) {
        DateTimeFormatter formatter = DateTimeFormat.forPattern("HH:mm");
        LocalTime time = formatter.parseLocalTime("14:10");
        time = time.plusMinutes(10);
        System.out.println(formatter.print(time));
    }       
}

Note that I would definitely use Joda Time instead of java.util.Date/Calendar if you possibly can - it's a much nicer API.

Spring profiles and testing

Looking at Biju's answer I found a working solution.

I created an extra context-file test-context.xml:

<context:property-placeholder location="classpath:config/spring-test.properties"/>

Containing the profile:

spring.profiles.active=localtest

And loading the test with:

@RunWith(SpringJUnit4ClassRunner.class)
@TestExecutionListeners({
    TestPreperationExecutionListener.class
    })
@Transactional
@ActiveProfiles(profiles = "localtest")
@ContextConfiguration(locations = {
    "classpath:config/test-context.xml" })
public class TestContext {

  @Test
  public void testContext(){

  }
}

This saves some work when creating multiple test-cases.

For vs. while in C programming?

If you want a loop to execute while a condition is true, and not for a certain number of iterations, it is much easier for someone else to understand:

while (cond_true)

than something like this:

for (; cond_true ; )

Visual Studio 2017: Display method references

CodeLens is not available in the Community editions. You need Professional or higher to switch it on.

In VS2015, one way to "get" CodeLens was to install the SQL Server Developer Tools (SSDT) but I believe this has been rectified in VS2017.

Still you can get all method reference by right clicking on the method and "Find All references"

enter image description here

onchange event on input type=range is not triggering in firefox while dragging

You could use the JavaScript "ondrag" event to fire continuously. It is better than "input" due to the following reasons:

  1. Browser support.

  2. Could differentiate between "ondrag" and "change" event. "input" fires for both drag and change.

In jQuery:

$('#sample').on('drag',function(e){

});

Reference: http://www.w3schools.com/TAgs/ev_ondrag.asp

Convert a String of Hex into ASCII in Java

//%%%%%%%%%%%%%%%%%%%%%% HEX to ASCII %%%%%%%%%%%%%%%%%%%%%%
public String convertHexToString(String hex){

 String ascii="";
 String str;

 // Convert hex string to "even" length
 int rmd,length;
 length=hex.length();
 rmd =length % 2;
 if(rmd==1)
 hex = "0"+hex;

  // split into two characters
  for( int i=0; i<hex.length()-1; i+=2 ){

      //split the hex into pairs
      String pair = hex.substring(i, (i + 2));
      //convert hex to decimal
      int dec = Integer.parseInt(pair, 16);
      str=CheckCode(dec);
      ascii=ascii+" "+str;
  }
  return ascii;
}

public String CheckCode(int dec){
  String str;

          //convert the decimal to character
        str = Character.toString((char) dec);

      if(dec<32 || dec>126 && dec<161)
             str="n/a";  
  return str;
}

VBScript How can I Format Date?

The output of FormatDateTime depends on configuration in Regional Settings in Control Panel. So in other countries FormatDateTime(d, 2) may for example return yyyy-MM-dd.

If you want your output to be "culture invariant", use myDateFormat() from stian.net's solution. If you just don't like slashes in dates and you don't care about date format in other countries, you can just use

Replace(FormatDateTime(d,2),"/","-")

How do I tokenize a string sentence in NLTK?

This is actually on the main page of nltk.org:

>>> import nltk
>>> sentence = """At eight o'clock on Thursday morning
... Arthur didn't feel very good."""
>>> tokens = nltk.word_tokenize(sentence)
>>> tokens
['At', 'eight', "o'clock", 'on', 'Thursday', 'morning',
'Arthur', 'did', "n't", 'feel', 'very', 'good', '.']

'Use of Unresolved Identifier' in Swift

My issue was calling my program with the same name as one of its cocoapods. It caused a conflict. Solution: Create a program different name.

Query to display all tablespaces in a database and datafiles

Neither databases, nor tablespaces nor data files belong to any user. Are you coming to this from an MS SQL background?

select tablespace_name, 
       file_name
from dba_tablespaces
order by tablespace_name, 
         file_name;

How to use Macro argument as string literal?

#define NAME(x) printf("Hello " #x);
main(){
    NAME(Ian)
}
//will print: Hello Ian

Why is this HTTP request not working on AWS Lambda?

Yeah, awendt answer is perfect. I'll just show my working code... I had the context.succeed('Blah'); line right after the reqPost.end(); line. Moving it to where I show below solved everything.

console.log('GW1');

var https = require('https');

exports.handler = function(event, context) {

    var body='';
    var jsonObject = JSON.stringify(event);

    // the post options
    var optionspost = {
        host: 'the_host',
        path: '/the_path',
        method: 'POST',
        headers: {
            'Content-Type': 'application/json',
        }
    };

    var reqPost = https.request(optionspost, function(res) {
        console.log("statusCode: ", res.statusCode);
        res.on('data', function (chunk) {
            body += chunk;
        });
        context.succeed('Blah');
    });

    reqPost.write(jsonObject);
    reqPost.end();
};

Quoting backslashes in Python string literals

What Harley said, except the last point - it's not actually necessary to change the '/'s into '\'s before calling open. Windows is quite happy to accept paths with forward slashes.

infile = open('c:/folder/subfolder/file.txt')

The only time you're likely to need the string normpathed is if you're passing to to another program via the shell (using os.system or the subprocess module).

AttributeError: 'module' object has no attribute

SoLvEd

Python is looking for the a object within your a.py module.

Either RENAME that file to something else or use

from __future__ import absolute_import 

at the top of your a.py module.

Monad in plain English? (For the OOP programmer with no FP background)

UPDATE: This question was the subject of an immensely long blog series, which you can read at Monads — thanks for the great question!

In terms that an OOP programmer would understand (without any functional programming background), what is a monad?

A monad is an "amplifier" of types that obeys certain rules and which has certain operations provided.

First, what is an "amplifier of types"? By that I mean some system which lets you take a type and turn it into a more special type. For example, in C# consider Nullable<T>. This is an amplifier of types. It lets you take a type, say int, and add a new capability to that type, namely, that now it can be null when it couldn't before.

As a second example, consider IEnumerable<T>. It is an amplifier of types. It lets you take a type, say, string, and add a new capability to that type, namely, that you can now make a sequence of strings out of any number of single strings.

What are the "certain rules"? Briefly, that there is a sensible way for functions on the underlying type to work on the amplified type such that they follow the normal rules of functional composition. For example, if you have a function on integers, say

int M(int x) { return x + N(x * 2); }

then the corresponding function on Nullable<int> can make all the operators and calls in there work together "in the same way" that they did before.

(That is incredibly vague and imprecise; you asked for an explanation that didn't assume anything about knowledge of functional composition.)

What are the "operations"?

  1. There is a "unit" operation (confusingly sometimes called the "return" operation) that takes a value from a plain type and creates the equivalent monadic value. This, in essence, provides a way to take a value of an unamplified type and turn it into a value of the amplified type. It could be implemented as a constructor in an OO language.

  2. There is a "bind" operation that takes a monadic value and a function that can transform the value, and returns a new monadic value. Bind is the key operation that defines the semantics of the monad. It lets us transform operations on the unamplified type into operations on the amplified type, that obeys the rules of functional composition mentioned before.

  3. There is often a way to get the unamplified type back out of the amplified type. Strictly speaking this operation is not required to have a monad. (Though it is necessary if you want to have a comonad. We won't consider those further in this article.)

Again, take Nullable<T> as an example. You can turn an int into a Nullable<int> with the constructor. The C# compiler takes care of most nullable "lifting" for you, but if it didn't, the lifting transformation is straightforward: an operation, say,

int M(int x) { whatever }

is transformed into

Nullable<int> M(Nullable<int> x) 
{ 
    if (x == null) 
        return null; 
    else 
        return new Nullable<int>(whatever);
}

And turning a Nullable<int> back into an int is done with the Value property.

It's the function transformation that is the key bit. Notice how the actual semantics of the nullable operation — that an operation on a null propagates the null — is captured in the transformation. We can generalize this.

Suppose you have a function from int to int, like our original M. You can easily make that into a function that takes an int and returns a Nullable<int> because you can just run the result through the nullable constructor. Now suppose you have this higher-order method:

static Nullable<T> Bind<T>(Nullable<T> amplified, Func<T, Nullable<T>> func)
{
    if (amplified == null) 
        return null;
    else
        return func(amplified.Value);
}

See what you can do with that? Any method that takes an int and returns an int, or takes an int and returns a Nullable<int> can now have the nullable semantics applied to it.

Furthermore: suppose you have two methods

Nullable<int> X(int q) { ... }
Nullable<int> Y(int r) { ... }

and you want to compose them:

Nullable<int> Z(int s) { return X(Y(s)); }

That is, Z is the composition of X and Y. But you cannot do that because X takes an int, and Y returns a Nullable<int>. But since you have the "bind" operation, you can make this work:

Nullable<int> Z(int s) { return Bind(Y(s), X); }

The bind operation on a monad is what makes composition of functions on amplified types work. The "rules" I handwaved about above are that the monad preserves the rules of normal function composition; that composing with identity functions results in the original function, that composition is associative, and so on.

In C#, "Bind" is called "SelectMany". Take a look at how it works on the sequence monad. We need to have two things: turn a value into a sequence and bind operations on sequences. As a bonus, we also have "turn a sequence back into a value". Those operations are:

static IEnumerable<T> MakeSequence<T>(T item)
{
    yield return item;
}
// Extract a value
static T First<T>(IEnumerable<T> sequence)
{
    // let's just take the first one
    foreach(T item in sequence) return item; 
    throw new Exception("No first item");
}
// "Bind" is called "SelectMany"
static IEnumerable<T> SelectMany<T>(IEnumerable<T> seq, Func<T, IEnumerable<T>> func)
{
    foreach(T item in seq)
        foreach(T result in func(item))
            yield return result;            
}

The nullable monad rule was "to combine two functions that produce nullables together, check to see if the inner one results in null; if it does, produce null, if it does not, then call the outer one with the result". That's the desired semantics of nullable.

The sequence monad rule is "to combine two functions that produce sequences together, apply the outer function to every element produced by the inner function, and then concatenate all the resulting sequences together". The fundamental semantics of the monads are captured in the Bind/SelectMany methods; this is the method that tells you what the monad really means.

We can do even better. Suppose you have a sequences of ints, and a method that takes ints and results in sequences of strings. We could generalize the binding operation to allow composition of functions that take and return different amplified types, so long as the inputs of one match the outputs of the other:

static IEnumerable<U> SelectMany<T,U>(IEnumerable<T> seq, Func<T, IEnumerable<U>> func)
{
    foreach(T item in seq)
        foreach(U result in func(item))
            yield return result;            
}

So now we can say "amplify this bunch of individual integers into a sequence of integers. Transform this particular integer into a bunch of strings, amplified to a sequence of strings. Now put both operations together: amplify this bunch of integers into the concatenation of all the sequences of strings." Monads allow you to compose your amplifications.

What problem does it solve and what are the most common places it's used?

That's rather like asking "what problems does the singleton pattern solve?", but I'll give it a shot.

Monads are typically used to solve problems like:

  • I need to make new capabilities for this type and still combine old functions on this type to use the new capabilities.
  • I need to capture a bunch of operations on types and represent those operations as composable objects, building up larger and larger compositions until I have just the right series of operations represented, and then I need to start getting results out of the thing
  • I need to represent side-effecting operations cleanly in a language that hates side effects

C# uses monads in its design. As already mentioned, the nullable pattern is highly akin to the "maybe monad". LINQ is entirely built out of monads; the SelectMany method is what does the semantic work of composition of operations. (Erik Meijer is fond of pointing out that every LINQ function could actually be implemented by SelectMany; everything else is just a convenience.)

To clarify the kind of understanding I was looking for, let's say you were converting an FP application that had monads into an OOP application. What would you do to port the responsibilities of the monads into the OOP app?

Most OOP languages do not have a rich enough type system to represent the monad pattern itself directly; you need a type system that supports types that are higher types than generic types. So I wouldn't try to do that. Rather, I would implement generic types that represent each monad, and implement methods that represent the three operations you need: turning a value into an amplified value, (maybe) turning an amplified value into a value, and transforming a function on unamplified values into a function on amplified values.

A good place to start is how we implemented LINQ in C#. Study the SelectMany method; it is the key to understanding how the sequence monad works in C#. It is a very simple method, but very powerful!


Suggested, further reading:

  1. For a more in-depth and theoretically sound explanation of monads in C#, I highly recommend my (Eric Lippert's) colleague Wes Dyer's article on the subject. This article is what explained monads to me when they finally "clicked" for me.
  2. A good illustration of why you might want a monad around (uses Haskell in it's examples).
  3. Sort of, "translation" of the previous article to JavaScript.

What's the advantage of a Java enum versus a class with public static final fields?

example:

public class CurrencyDenom {
   public static final int PENNY = 1;
 public static final int NICKLE = 5;
 public static final int DIME = 10;
public static final int QUARTER = 25;}

Limitation of java Constants

1) No Type-Safety: First of all it’s not type-safe; you can assign any valid int value to int e.g. 99 though there is no coin to represent that value.

2) No Meaningful Printing: printing value of any of these constant will print its numeric value instead of meaningful name of coin e.g. when you print NICKLE it will print "5" instead of "NICKLE"

3) No namespace: to access the currencyDenom constant we need to prefix class name e.g. CurrencyDenom.PENNY instead of just using PENNY though this can also be achieved by using static import in JDK 1.5

Advantage of enum

1) Enums in Java are type-safe and has there own name-space. It means your enum will have a type for example "Currency" in below example and you can not assign any value other than specified in Enum Constants.

public enum Currency {PENNY, NICKLE, DIME, QUARTER};

Currency coin = Currency.PENNY; coin = 1; //compilation error

2) Enum in Java are reference type like class or interface and you can define constructor, methods and variables inside java Enum which makes it more powerful than Enum in C and C++ as shown in next example of Java Enum type.

3) You can specify values of enum constants at the creation time as shown in below example: public enum Currency {PENNY(1), NICKLE(5), DIME(10), QUARTER(25)}; But for this to work you need to define a member variable and a constructor because PENNY (1) is actually calling a constructor which accepts int value , see below example.

public enum Currency {
    PENNY(1), NICKLE(5), DIME(10), QUARTER(25);
    private int value;

    private Currency(int value) {
            this.value = value;
    }
}; 

Reference: https://javarevisited.blogspot.com/2011/08/enum-in-java-example-tutorial.html

Get generic type of class at runtime

I found this to be a simple understandable and easily explainable solution

public class GenericClass<T> {

    private Class classForT(T...t) {
        return t.getClass().getComponentType();
    }

    public static void main(String[] args) {
        GenericClass<String> g = new GenericClass<String>();

        System.out.println(g.classForT());
        System.out.println(String.class);
    }
}

Adding Image to xCode by dragging it from File

For xCode 10, first you need to add the image in your assetsCatalogue and then type this:

let imageView = UIImageView(image: #imageLiteral(resourceName: "type the name of your image here..."))

For beginners, let imageView is the name of the UIImageView object we are about to create.

An example for embedding an image into a viewControler file would look like this:

import UIKit

class TutorialViewCotroller: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        let imageView = UIImageView(image: #imageLiteral(resourceName: "intoImage"))
        view.addSubview(imageView)
    }
}

Please notice that I did not use any extension for the image file name, as in my case it is a group of images.

CSS border less than 1px

It's impossible to draw a line on screen that's thinner than one pixel. Try using a more subtle color for the border instead.

Why is Tkinter Entry's get function returning nothing?

It looks like you may be confused as to when commands are run. In your example, you are calling the get method before the GUI has a chance to be displayed on the screen (which happens after you call mainloop.

Try adding a button that calls the get method. This is much easier if you write your application as a class. For example:

import tkinter as tk

class SampleApp(tk.Tk):
    def __init__(self):
        tk.Tk.__init__(self)
        self.entry = tk.Entry(self)
        self.button = tk.Button(self, text="Get", command=self.on_button)
        self.button.pack()
        self.entry.pack()

    def on_button(self):
        print(self.entry.get())

app = SampleApp()
app.mainloop()

Run the program, type into the entry widget, then click on the button.

CSS text-overflow: ellipsis; not working?

MUST contain

  text-overflow: ellipsis;
  white-space: nowrap;
  overflow: hidden;

MUST NOT contain

display: inline

SHOULD contain

position: sticky

How do I rotate text in css?

In your case, it's the best to use rotate option from transform property as mentioned before. There is also writing-mode property and it works like rotate(90deg) so in your case, it should be rotated after it's applied. Even it's not the right solution in this case but you should be aware of this property.

Example:

writing-mode:vertical-rl;

More about transform: https://kolosek.com/css-transform/

More about writing-mode: https://css-tricks.com/almanac/properties/w/writing-mode/

Http post and get request in angular 6

Update : In angular 7, they are the same as 6

In angular 6

the complete answer found in live example

  /** POST: add a new hero to the database */
  addHero (hero: Hero): Observable<Hero> {
 return this.http.post<Hero>(this.heroesUrl, hero, httpOptions)
  .pipe(
    catchError(this.handleError('addHero', hero))
  );
}
  /** GET heroes from the server */
 getHeroes (): Observable<Hero[]> {
return this.http.get<Hero[]>(this.heroesUrl)
  .pipe(
    catchError(this.handleError('getHeroes', []))
  );
}

it's because of pipeable/lettable operators which now angular is able to use tree-shakable and remove unused imports and optimize the app

some rxjs functions are changed

do -> tap
catch -> catchError
switch -> switchAll
finally -> finalize

more in MIGRATION

and Import paths

For JavaScript developers, the general rule is as follows:

rxjs: Creation methods, types, schedulers and utilities

import { Observable, Subject, asapScheduler, pipe, of, from, interval, merge, fromEvent } from 'rxjs';

rxjs/operators: All pipeable operators:

import { map, filter, scan } from 'rxjs/operators';

rxjs/webSocket: The web socket subject implementation

import { webSocket } from 'rxjs/webSocket';

rxjs/ajax: The Rx ajax implementation

import { ajax } from 'rxjs/ajax';

rxjs/testing: The testing utilities

import { TestScheduler } from 'rxjs/testing';

and for backward compatability you can use rxjs-compat

Send mail via Gmail with PowerShell V2's Send-MailMessage

I used Christian's Feb 12 solution and I'm also just beginning to learn PowerShell. As far as attachments, I was poking around with Get-Member learning how it works and noticed that Send() has two definitions... the second definition takes a System.Net.Mail.MailMessage object which allows for Attachments and many more powerful and useful features like Cc and Bcc. Here's an example that has attachments (to be mixed with his above example):

# append to Christian's code above --^
$emailMessage = New-Object System.Net.Mail.MailMessage
$emailMessage.From = $EmailFrom
$emailMessage.To.Add($EmailTo)
$emailMessage.Subject = $Subject
$emailMessage.Body = $Body
$emailMessage.Attachments.Add("C:\Test.txt")
$SMTPClient.Send($emailMessage)

Enjoy!

How get value from URL

You can access those values with the global $_GET variable

//www.example.com/index.php?id=7
print $_GET['id']; // prints "7"

You should check all "incoming" user data - so here, that "id" is an INT. Don't use it directly in your SQL (vulnerable to SQL injections).

What is the difference between a string and a byte string?

The Python languages includes str and bytes as standard "Built-in Types". In other words, they are both classes. I don't think it's worthwhile trying to rationalize why Python has been implemented this way.

Having said that, str and bytes are very similar to one another. Both share most of the same methods. The following methods are unique to the str class:

casefold
encode
format
format_map
isdecimal
isidentifier
isnumeric
isprintable

The following methods are unique to the bytes class:

decode
fromhex
hex

How to set border's thickness in percentages?

Percentage values are not applicable to border-width in CSS. This is listed in the spec.

You will need to use JavaScript to calculate the percentage of the element's width or whatever length quantity you need, and apply the result in px or similar to the element's borders.

Implementing a slider (SeekBar) in Android

How to implement a SeekBar

enter image description here

Add the SeekBar to your layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/textView"
        android:layout_margin="20dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <SeekBar
        android:id="@+id/seekBar"
        android:max="100"
        android:progress="50"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

Notes

  • max is the highest value that the seek bar can go to. The default is 100. The minimum is 0. The xml min value is only available from API 26, but you can just programmatically convert the 0-100 range to whatever you need for earlier versions.
  • progress is the initial position of the slider dot (called a "thumb").
  • For a vertical SeekBar use android:rotation="270".

Listen for changes in code

public class MainActivity extends AppCompatActivity {

    TextView tvProgressLabel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // set a change listener on the SeekBar
        SeekBar seekBar = findViewById(R.id.seekBar);
        seekBar.setOnSeekBarChangeListener(seekBarChangeListener);

        int progress = seekBar.getProgress();
        tvProgressLabel = findViewById(R.id.textView);
        tvProgressLabel.setText("Progress: " + progress);
    }

    SeekBar.OnSeekBarChangeListener seekBarChangeListener = new SeekBar.OnSeekBarChangeListener() {

        @Override
        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
            // updated continuously as the user slides the thumb
            tvProgressLabel.setText("Progress: " + progress);
        }

        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {
            // called when the user first touches the SeekBar
        }

        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {
            // called after the user finishes moving the SeekBar
        }
    };
}

Notes

  • If you don't need to do any updates while the user is moving the seekbar, then you can just update the UI in onStopTrackingTouch.

See also

How to get the position of a character in Python?

A solution with numpy for quick access to all indexes:

string_array = np.array(list(my_string))
char_indexes = np.where(string_array == 'C')

JavaScript hashmap equivalent

You'd have to store couplets of object/value pairs in some internal state:

HashMap = function(){
  this._dict = [];
}

HashMap.prototype._get = function(key){
  for(var i=0, couplet; couplet = this._dict[i]; i++){
    if(couplet[0] === key){
      return couplet;
    }
  }
}

HashMap.prototype.put = function(key, value){
  var couplet = this._get(key);
  if(couplet){
    couplet[1] = value;
  }else{
    this._dict.push([key, value]);
  }
  return this; // for chaining
}
HashMap.prototype.get = function(key){
  var couplet = this._get(key);
  if(couplet){
    return couplet[1];
  }
}

And use it as such:

var color = {}; // Unique object instance
var shape = {}; // Unique object instance
var map = new HashMap();
map.put(color, "blue");
map.put(shape, "round");
console.log("Item is", map.get(color), "and", map.get(shape));

Of course, this implementation is also somewhere along the lines of O(n). Eugene's examples are the only way to get a hash that works with any sort of speed you'd expect from a real hash.

Another approach, along the lines of Eugene's answer is to somehow attach a unique ID to all objects. One of my favorite approaches is to take one of the built-in methods inherited from the Object superclass, replace it with a custom function passthrough and attach properties to that function object. If you were to rewrite my HashMap method to do this, it would look like:

HashMap = function(){
  this._dict = {};
}

HashMap.prototype._shared = {id: 1};
HashMap.prototype.put = function put(key, value){
  if(typeof key == "object"){
    if(!key.hasOwnProperty._id){
      key.hasOwnProperty = function(key){
        return Object.prototype.hasOwnProperty.call(this, key);
      }
      key.hasOwnProperty._id = this._shared.id++;
    }
    this._dict[key.hasOwnProperty._id] = value;
  }else{
    this._dict[key] = value;
  }
  return this; // for chaining
}

HashMap.prototype.get = function get(key){
  if(typeof key == "object"){
    return this._dict[key.hasOwnProperty._id];
  }
  return this._dict[key];
}

This version appears to be only slightly faster, but in theory it will be significantly faster for large data sets.

How to change current working directory using a batch file

Specify /D to change the drive also.

CD /D %root%

How to capture the browser window close event?

Unfortunately, whether it is a reload, new page redirect, or browser close the event will be triggered. An alternative is catch the id triggering the event and if it is form dont trigger any function and if it is not the id of the form then do what you want to do when the page closes. I am not sure if that is also possible directly and is tedious.

You can do some small things before the customer closes the tab. javascript detect browser close tab/close browser but if your list of actions are big and the tab closes before it is finished you are helpless. You can try it but with my experience donot depend on it.

window.addEventListener("beforeunload", function (e) {
  var confirmationMessage = "\o/";
  /* Do you small action code here */
  (e || window.event).returnValue = confirmationMessage; //Gecko + IE
  return confirmationMessage;                            //Webkit, Safari, Chrome
});

https://developer.mozilla.org/en-US/docs/Web/Reference/Events/beforeunload?redirectlocale=en-US&redirectslug=DOM/Mozilla_event_reference/beforeunload

R memory management / cannot allocate vector of size n Mb

For Windows users, the following helped me a lot to understand some memory limitations:

  • before opening R, open the Windows Resource Monitor (Ctrl-Alt-Delete / Start Task Manager / Performance tab / click on bottom button 'Resource Monitor' / Memory tab)
  • you will see how much RAM memory us already used before you open R, and by which applications. In my case, 1.6 GB of the total 4GB are used. So I will only be able to get 2.4 GB for R, but now comes the worse...
  • open R and create a data set of 1.5 GB, then reduce its size to 0.5 GB, the Resource Monitor shows my RAM is used at nearly 95%.
  • use gc() to do garbage collection => it works, I can see the memory use go down to 2 GB

enter image description here

Additional advice that works on my machine:

  • prepare the features, save as an RData file, close R, re-open R, and load the train features. The Resource Manager typically shows a lower Memory usage, which means that even gc() does not recover all possible memory and closing/re-opening R works the best to start with maximum memory available.
  • the other trick is to only load train set for training (do not load the test set, which can typically be half the size of train set). The training phase can use memory to the maximum (100%), so anything available is useful. All this is to take with a grain of salt as I am experimenting with R memory limits.

Android Studio says "cannot resolve symbol" but project compiles

Try changing the order of dependencies in File > Project Structure > (select your project) > Dependencies.

Invalidate Caches didn't work for me, but moving my build from the bottom of the list to the top did.

Display an array in a readable/hierarchical format

I have a basic function:

function prettyPrint($a) {
    echo "<pre>";
    print_r($a);
    echo "</pre>";
}

prettyPrint($data);

EDIT: Optimised function

function prettyPrint($a) {
    echo '<pre>'.print_r($a,1).'</pre>';
}

EDIT: Moar Optimised function with custom tag support

function prettyPrint($a, $t='pre') {echo "<$t>".print_r($a,1)."</$t>";}

How to save a pandas DataFrame table as a png

The following would need extensive customisation to format the table correctly, but the bones of it works:

import numpy as np
from PIL import Image, ImageDraw, ImageFont
import pandas as pd

df = pd.DataFrame({ 'A' : 1.,
                     'B' : pd.Series(1,index=list(range(4)),dtype='float32'),
                     'C' : np.array([3] * 4,dtype='int32'),
                     'D' : pd.Categorical(["test","train","test","train"]),
                     'E' : 'foo' })


class DrawTable():
    def __init__(self,_df):
        self.rows,self.cols = _df.shape
        img_size = (300,200)
        self.border = 50
        self.bg_col = (255,255,255)
        self.div_w = 1
        self.div_col = (128,128,128)
        self.head_w = 2
        self.head_col = (0,0,0)
        self.image = Image.new("RGBA", img_size,self.bg_col)
        self.draw = ImageDraw.Draw(self.image)
        self.draw_grid()
        self.populate(_df)
        self.image.show()
    def draw_grid(self):
        width,height = self.image.size
        row_step = (height-self.border*2)/(self.rows)
        col_step = (width-self.border*2)/(self.cols)
        for row in range(1,self.rows+1):
            self.draw.line((self.border-row_step//2,self.border+row_step*row,width-self.border,self.border+row_step*row),fill=self.div_col,width=self.div_w)
            for col in range(1,self.cols+1):
                self.draw.line((self.border+col_step*col,self.border-col_step//2,self.border+col_step*col,height-self.border),fill=self.div_col,width=self.div_w)
        self.draw.line((self.border-row_step//2,self.border,width-self.border,self.border),fill=self.head_col,width=self.head_w)
        self.draw.line((self.border,self.border-col_step//2,self.border,height-self.border),fill=self.head_col,width=self.head_w)
        self.row_step = row_step
        self.col_step = col_step
    def populate(self,_df2):
        font = ImageFont.load_default().font
        for row in range(self.rows):
            print(_df2.iloc[row,0])
            self.draw.text((self.border-self.row_step//2,self.border+self.row_step*row),str(_df2.index[row]),font=font,fill=(0,0,128))
            for col in range(self.cols):
                text = str(_df2.iloc[row,col])
                text_w, text_h = font.getsize(text)
                x_pos = self.border+self.col_step*(col+1)-text_w
                y_pos = self.border+self.row_step*row
                self.draw.text((x_pos,y_pos),text,font=font,fill=(0,0,128))
        for col in range(self.cols):
            text = str(_df2.columns[col])
            text_w, text_h = font.getsize(text)
            x_pos = self.border+self.col_step*(col+1)-text_w
            y_pos = self.border - self.row_step//2
            self.draw.text((x_pos,y_pos),text,font=font,fill=(0,0,128))
    def save(self,filename):
        try:
            self.image.save(filename,mode='RGBA')
            print(filename," Saved.")
        except:
            print("Error saving:",filename)




table1 = DrawTable(df)
table1.save('C:/Users/user/Pictures/table1.png')

The output looks like this:

enter image description here

Java Refuses to Start - Could not reserve enough space for object heap

ulimit max memory size and virtual memory set to unlimited?

Access VBA | How to replace parts of a string with another string

You could use a function similar to this also, it would allow you to add in different cases where you would like to change values:

Public Function strReplace(varValue As Variant) as Variant

    Select Case varValue

        Case "Avenue"
            strReplace = "Ave"

        Case "North"
            strReplace = "N"

        Case Else
            strReplace = varValue

    End Select

End Function

Then your SQL would read something like:

SELECT strReplace(Address) As Add FROM Tablename

Spring: return @ResponseBody "ResponseEntity<List<JSONObject>>"

Personally, I prefer changing the method signature to:

public ResponseEntity<?>

This gives the advantage of possibly returning an error message as single item for services which, when ok, return a list of items.

When returning I don't use any type (which is unused in this case anyway):

return new ResponseEntity<>(entities, HttpStatus.OK);

Can't find keyplane that supports type 4 for keyboard iPhone-Portrait-NumberPad; using 3876877096_Portrait_iPhone-Simple-Pad_Default

I am using xcode with ios 8 just uncheck the connect harware keyboard option in your Simulator-> Hardware-> Keyboard-> Connect Hardware Keyboard.

This will solve the issue.

Initializing C# auto-properties

Update - the answer below was written before C# 6 came along. In C# 6 you can write:

public class Foo
{
    public string Bar { get; set; } = "bar";
}

You can also write read-only automatically-implemented properties, which are only writable in the constructor (but can also be given a default initial value):

public class Foo
{
    public string Bar { get; }

    public Foo(string bar)
    {
        Bar = bar;
    }
}

It's unfortunate that there's no way of doing this right now. You have to set the value in the constructor. (Using constructor chaining can help to avoid duplication.)

Automatically implemented properties are handy right now, but could certainly be nicer. I don't find myself wanting this sort of initialization as often as a read-only automatically implemented property which could only be set in the constructor and would be backed by a read-only field.

This hasn't happened up until and including C# 5, but is being planned for C# 6 - both in terms of allowing initialization at the point of declaration, and allowing for read-only automatically implemented properties to be initialized in a constructor body.

How to force browser to download file?

Set content-type and other headers before you write the file out. For small files the content is buffered, and the browser gets the headers first. For big ones the data come first.

How do I use typedef and typedef enum in C?

typedef enum state {DEAD,ALIVE} State;
|     | |                     | |   |^ terminating semicolon, required! 
|     | |   type specifier    | |   |
|     | |                     | ^^^^^  declarator (simple name)
|     | |                     |    
|     | ^^^^^^^^^^^^^^^^^^^^^^^  
|     |
^^^^^^^-- storage class specifier (in this case typedef)

The typedef keyword is a pseudo-storage-class specifier. Syntactically, it is used in the same place where a storage class specifier like extern or static is used. It doesn't have anything to do with storage. It means that the declaration doesn't introduce the existence of named objects, but rather, it introduces names which are type aliases.

After the above declaration, the State identifier becomes an alias for the type enum state {DEAD,ALIVE}. The declaration also provides that type itself. However that isn't typedef doing it. Any declaration in which enum state {DEAD,ALIVE} appears as a type specifier introduces that type into the scope:

enum state {DEAD, ALIVE} stateVariable;

If enum state has previously been introduced the typedef has to be written like this:

typedef enum state State;

otherwise the enum is being redefined, which is an error.

Like other declarations (except function parameter declarations), the typedef declaration can have multiple declarators, separated by a comma. Moreover, they can be derived declarators, not only simple names:

typedef unsigned long ulong, *ulongptr;
|     | |           | |  1 | |   2   |
|     | |           | |    | ^^^^^^^^^--- "pointer to" declarator
|     | |           | ^^^^^^------------- simple declarator
|     | ^^^^^^^^^^^^^-------------------- specifier-qualifier list
^^^^^^^---------------------------------- storage class specifier

This typedef introduces two type names ulong and ulongptr, based on the unsigned long type given in the specifier-qualifier list. ulong is just a straight alias for that type. ulongptr is declared as a pointer to unsigned long, thanks to the * syntax, which in this role is a kind of type construction operator which deliberately mimics the unary * for pointer dereferencing used in expressions. In other words ulongptr is an alias for the "pointer to unsigned long" type.

Alias means that ulongptr is not a distinct type from unsigned long *. This is valid code, requiring no diagnostic:

unsigned long *p = 0;
ulongptr q = p;

The variables q and p have exactly the same type.

The aliasing of typedef isn't textual. For instance if user_id_t is a typedef name for the type int, we may not simply do this:

unsigned user_id_t uid;  // error! programmer hoped for "unsigned int uid". 

This is an invalid type specifier list, combining unsigned with a typedef name. The above can be done using the C preprocessor:

#define user_id_t int
unsigned user_id_t uid;

whereby user_id_t is macro-expanded to the token int prior to syntax analysis and translation. While this may seem like an advantage, it is a false one; avoid this in new programs.

Among the disadvantages that it doesn't work well for derived types:

 #define silly_macro int *

 silly_macro not, what, you, think;

This declaration doesn't declare what, you and think as being of type "pointer to int" because the macro-expansion is:

 int * not, what, you, think;

The type specifier is int, and the declarators are *not, what, you and think. So not has the expected pointer type, but the remaining identifiers do not.

And that's probably 99% of everything about typedef and type aliasing in C.

Fatal error compiling: invalid target release: 1.8 -> [Help 1]

Using IntelliJ I just had to install another (higher) JDK Version. After restarting IDE, everything worked and even all dependencies were solved.

How can I convert JSON to CSV?

This code should work for you, assuming that your JSON data is in a file called data.json.

import json
import csv

with open("data.json") as file:
    data = json.load(file)

with open("data.csv", "w") as file:
    csv_file = csv.writer(file)
    for item in data:
        fields = list(item['fields'].values())
        csv_file.writerow([item['pk'], item['model']] + fields)

What is the most efficient/quickest way to loop through rows in VBA (excel)?

EDIT Summary and reccomendations

Using a for each cell in range construct is not in itself slow. What is slow is repeated access to Excel in the loop (be it reading or writing cell values, format etc, inserting/deleting rows etc).

What is too slow depends entierly on your needs. A Sub that takes minutes to run might be OK if only used rarely, but another that takes 10s might be too slow if run frequently.

So, some general advice:

  1. keep it simple at first. If the result is too slow for your needs, then optimise
  2. focus on optimisation of the content of the loop
  3. don't just assume a loop is needed. There are sometime alternatives
  4. if you need to use cell values (a lot) inside the loop, load them into a variant array outside the loop.
  5. a good way to avoid complexity with inserts is to loop the range from the bottom up
    (for index = max to min step -1)
  6. if you can't do that and your 'insert a row here and there' is not too many, consider reloading the array after each insert
  7. If you need to access cell properties other than value, you are stuck with cell references
  8. To delete a number of rows consider building a range reference to a multi area range in the loop, then delete that range in one go after the loop

eg (not tested!)

Dim rngToDelete as range
for each rw in rng.rows
    if need to delete rw then

        if rngToDelete is nothing then
            set rngToDelete = rw
        else
            set rngToDelete = Union(rngToDelete, rw)
        end if

    endif
next
rngToDelete.EntireRow.Delete

Original post

Conventional wisdom says that looping through cells is bad and looping through a variant array is good. I too have been an advocate of this for some time. Your question got me thinking, so I did some short tests with suprising (to me anyway) results:

test data set: a simple list in cells A1 .. A1000000 (thats 1,000,000 rows)

Test case 1: loop an array

Dim v As Variant
Dim n As Long

T1 = GetTickCount
Set r = Range("$A$1", Cells(Rows.Count, "A").End(xlUp)).Cells
v = r
For n = LBound(v, 1) To UBound(v, 1)
    'i = i + 1
    'i = r.Cells(n, 1).Value 'i + 1
Next
Debug.Print "Array Time = " & (GetTickCount - T1) / 1000#
Debug.Print "Array Count = " & Format(n, "#,###")

Result:

Array Time = 0.249 sec
Array Count = 1,000,001

Test Case 2: loop the range

T1 = GetTickCount
Set r = Range("$A$1", Cells(Rows.Count, "A").End(xlUp)).Cells
For Each c In r
Next c
Debug.Print "Range Time = " & (GetTickCount - T1) / 1000#
Debug.Print "Range Count = " & Format(r.Cells.Count, "#,###")

Result:

Range Time = 0.296 sec
Range Count = 1,000,000

So,looping an array is faster but only by 19% - much less than I expected.

Test 3: loop an array with a cell reference

T1 = GetTickCount
Set r = Range("$A$1", Cells(Rows.Count, "A").End(xlUp)).Cells
v = r
For n = LBound(v, 1) To UBound(v, 1)
    i = r.Cells(n, 1).Value
Next
Debug.Print "Array Time = " & (GetTickCount - T1) / 1000# & " sec"
Debug.Print "Array Count = " & Format(i, "#,###")

Result:

Array Time = 5.897 sec
Array Count = 1,000,000

Test case 4: loop range with a cell reference

T1 = GetTickCount
Set r = Range("$A$1", Cells(Rows.Count, "A").End(xlUp)).Cells
For Each c In r
    i = c.Value
Next c
Debug.Print "Range Time = " & (GetTickCount - T1) / 1000# & " sec"
Debug.Print "Range Count = " & Format(r.Cells.Count, "#,###")

Result:

Range Time = 2.356 sec
Range Count = 1,000,000

So event with a single simple cell reference, the loop is an order of magnitude slower, and whats more, the range loop is twice as fast!

So, conclusion is what matters most is what you do inside the loop, and if speed really matters, test all the options

FWIW, tested on Excel 2010 32 bit, Win7 64 bit All tests with

  • ScreenUpdating off,
  • Calulation manual,
  • Events disabled.

In Python, how do I determine if an object is iterable?

I often find convenient, inside my scripts, to define an iterable function. (Now incorporates Alfe's suggested simplification):

import collections

def iterable(obj):
    return isinstance(obj, collections.Iterable):

so you can test if any object is iterable in the very readable form

if iterable(obj):
    # act on iterable
else:
    # not iterable

as you would do with thecallable function

EDIT: if you have numpy installed, you can simply do: from numpy import iterable, which is simply something like

def iterable(obj):
    try: iter(obj)
    except: return False
    return True

If you do not have numpy, you can simply implement this code, or the one above.

Global javascript variable inside document.ready

declare this

var intro;

outside of $(document).ready() because, $(document).ready() will hide your variable from global scope.

Code

var intro;

$(document).ready(function() {
    if ($('.intro_check').is(':checked')) {
        intro = true;
        $('.intro').wrap('<div class="disabled"></div>');
    };
    $('.intro_check').change(function(){
        if(this.checked) {
            intro = false;
            $('.enabled').removeClass('enabled').addClass('disabled');
        } else {
            intro = true;
            if($('.intro').exists()) {
                $('.disabled').removeClass('disabled').addClass('enabled'); 
            } else {
                $('.intro').wrap('<div class="disabled"></div>');
            }
        }
    });
});

According to @Zakaria comment

Another way:

window.intro = undefined;

$(document).ready(function() {
    if ($('.intro_check').is(':checked')) {
        window.intro = true;
        $('.intro').wrap('<div class="disabled"></div>');
    };
    $('.intro_check').change(function(){
        if(this.checked) {
            window.intro = false;
            $('.enabled').removeClass('enabled').addClass('disabled');
        } else {
            window.intro = true;
            if($('.intro').exists()) {
                $('.disabled').removeClass('disabled').addClass('enabled'); 
            } else {
                $('.intro').wrap('<div class="disabled"></div>');
            }
        }
    });
});

Note

console.log(intro);

outside of DOM ready function (currently you've) will log undefined, but within DOM ready it will give you true/ false.

Your outer console.log execute before DOM ready execute, because DOM ready execute after all resource appeared to DOM i.e after DOM is prepared, so I think you'll always get absurd result.


According to comment of @W0rldart

I need to use it outside of DOM ready function

You can use following approach:

var intro = undefined;

$(document).ready(function() {
    if ($('.intro_check').is(':checked')) {
        intro = true;
        introCheck();
        $('.intro').wrap('<div class="disabled"></div>');
    };
    $('.intro_check').change(function() {
        if (this.checked) {
            intro = true;
        } else {
            intro = false;
        }
        introCheck();
    });

});

function introCheck() {
    console.log(intro);
}

After change the value of intro I called a function that will fire with new value of intro.

Refresh certain row of UITableView based on Int in Swift

let indexPathRow:Int = 0
let indexPosition = IndexPath(row: indexPathRow, section: 0)
tableView.reloadRows(at: [indexPosition], with: .none)

MySQL direct INSERT INTO with WHERE clause

INSERT syntax cannot have WHERE but you can use UPDATE.

The syntax is as follows:

UPDATE table_name

SET column1 = value1, column2 = value2, ...

WHERE condition;

How do I add space between items in an ASP.NET RadioButtonList

<asp:RadioButtonList ID="rbn" runat="server" RepeatLayout="Table" RepeatColumns="2"
                        Width="100%" >
                        <asp:ListItem Text="1"></asp:ListItem>
                        <asp:ListItem Text="2"></asp:ListItem>
                        <asp:ListItem Text="3"></asp:ListItem>
                        <asp:ListItem Text="4"></asp:ListItem>
                    </asp:RadioButtonList>

JavaScript set object key by variable

You need to make the object first, then use [] to set it.

var key = "happyCount";
var obj = {};
obj[key] = someValueArray;
myArray.push(obj);

UPDATE 2018:

If you're able to use ES6 and Babel, you can use this new feature:

{
    [yourKeyVariable]: someValueArray,
}  

How to set dropdown arrow in spinner?

                   <Spinner
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:layout_marginRight="16dp"
                    android:paddingLeft="10dp"
                    android:spinnerMode="dropdown" />

How to filter a data frame

Another method utilizing the dplyr package:

library(dplyr)
df <- mtcars %>%
        filter(mpg > 25)

Without the chain (%>%) operator:

library(dplyr)
df <- filter(mtcars, mpg > 25)

What is getattr() exactly and how do I use it?

I sometimes use getattr(..) to lazily initialise attributes of secondary importance just before they are used in the code.

Compare the following:

class Graph(object):
    def __init__(self):
        self.n_calls_to_plot = 0

    #...
    #A lot of code here
    #...

    def plot(self):
        self.n_calls_to_plot += 1

To this:

class Graph(object):
    def plot(self):
        self.n_calls_to_plot = 1 + getattr(self, "n_calls_to_plot", 0)

The advantage of the second way is that n_calls_to_plot only appears around the place in the code where it is used. This is good for readability, because (1) you can immediately see what value it starts with when reading how it's used, (2) it doesn't introduce a distraction into the __init__(..) method, which ideally should be about the conceptual state of the class, rather than some utility counter that is only used by one of the function's methods for technical reasons, such as optimisation, and has nothing to do with the meaning of the object.

PHP errors NOT being displayed in the browser [Ubuntu 10.10]

it's should overlap, so it turned off. Try to open in your text editor and find display_errors and turn it on. It works for me

How to create a custom scrollbar on a div (Facebook style)

If you're looking for a Facebook like scroll bar, then I'd highly recommend you take a look at this one:

http://rocha.la/jQuery-slimScroll

How do I import from Excel to a DataSet using Microsoft.Office.Interop.Excel?

Have you seen this one? From http://www.aspspider.com/resources/Resource510.aspx:

public DataTable Import(String path)
{
    Microsoft.Office.Interop.Excel.Application app = new Microsoft.Office.Interop.Excel.Application();
    Microsoft.Office.Interop.Excel.Workbook workBook = app.Workbooks.Open(path, 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);

    Microsoft.Office.Interop.Excel.Worksheet workSheet = (Microsoft.Office.Interop.Excel.Worksheet)workBook.ActiveSheet;

    int index = 0;
    object rowIndex = 2;

    DataTable dt = new DataTable();
    dt.Columns.Add("FirstName");
    dt.Columns.Add("LastName");
    dt.Columns.Add("Mobile");
    dt.Columns.Add("Landline");
    dt.Columns.Add("Email");
    dt.Columns.Add("ID");

    DataRow row;

    while (((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 1]).Value2 != null)
    {

        row = dt.NewRow();
        row[0] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 1]).Value2);
        row[1] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 2]).Value2);
        row[2] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 3]).Value2);
        row[3] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 4]).Value2);
        row[4] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 5]).Value2);
        index++;

        rowIndex = 2 + index;
        dt.Rows.Add(row);
    }
    app.Workbooks.Close();
    return dt;
}

How can you float: right in React Native?

why does the Text take up the full space of the View, instead of just the space for "Hello"?

Because the View is a flex container and by default has flexDirection: 'column' and alignItems: 'stretch', which means that its children should be stretched out to fill its width.

(Note, per the docs, that all components in React Native are display: 'flex' by default and that display: 'inline' does not exist at all. In this way, the default behaviour of a Text within a View in React Native differs from the default behaviour of span within a div on the web; in the latter case, the span would not fill the width of the div because a span is an inline element by default. There is no such concept in React Native.)

How can the Text be floated / aligned to the right?

The float property doesn't exist in React Native, but there are loads of options available to you (with slightly different behaviours) that will let you right-align your text. Here are the ones I can think of:

1. Use textAlign: 'right' on the Text element

<View>
  <Text style={{textAlign: 'right'}}>Hello, World!</Text>
</View>

(This approach doesn't change the fact that the Text fills the entire width of the View; it just right-aligns the text within the Text.)

2. Use alignSelf: 'flex-end' on the Text

<View>
  <Text style={{alignSelf: 'flex-end'}}>Hello, World!</Text>
</View>

This shrinks the Text element to the size required to hold its content and puts it at the end of the cross direction (the horizontal direction, by default) of the View.

3. Use alignItems: 'flex-end' on the View

<View style={{alignItems: 'flex-end'}}>
  <Text>Hello, World!</Text>
</View>

This is equivalent to setting alignSelf: 'flex-end' on all the View's children.

4. Use flexDirection: 'row' and justifyContent: 'flex-end' on the View

<View style={{flexDirection: 'row', justifyContent: 'flex-end'}}>
  <Text>Hello, World!</Text>
</View>

flexDirection: 'row' sets the main direction of layout to be horizontal instead of vertical; justifyContent is just like alignItems, but controls alignment in the main direction instead of the cross direction.

5. Use flexDirection: 'row' on the View and marginLeft: 'auto' on the Text

<View style={{flexDirection: 'row'}}>
  <Text style={{marginLeft: 'auto'}}>Hello, World!</Text>
</View>

This approach is demonstrated, in the context of the web and real CSS, at https://stackoverflow.com/a/34063808/1709587.

6. Use position: 'absolute' and right: 0 on the Text:

<View>
  <Text style={{position: 'absolute', right: 0}}>Hello, World!</Text>
</View>

Like in real CSS, this takes the Text "out of flow", meaning that its siblings will be able to overlap it and its vertical position will be at the top of the View by default (although you can explicitly set a distance from the top of the View using the top style property).


Naturally, which of these various approaches you want to use - and whether the choice between them even matters at all - will depend upon your precise circumstances.

java comparator, how to sort by integer?

Simply changing

public int compare(Dog d, Dog d1) {
  return d.age - d1.age;
}

to

public int compare(Dog d, Dog d1) {
  return d1.age - d.age;
}

should sort them in the reverse order of age if that is what you are looking for.

Update:

@Arian is right in his comments, one of the accepted ways of declaring a comparator for a dog would be where you declare it as a public static final field in the class itself.

class Dog implements Comparable<Dog> {
    private String name;
    private int age;

    public static final Comparator<Dog> DESCENDING_COMPARATOR = new Comparator<Dog>() {
        // Overriding the compare method to sort the age
        public int compare(Dog d, Dog d1) {
            return d.age - d1.age;
        }
    };

    Dog(String n, int a) {
        name = n;
        age = a;
    }

    public String getDogName() {
        return name;
    }

    public int getDogAge() {
        return age;
    }

    // Overriding the compareTo method
    public int compareTo(Dog d) {
        return (this.name).compareTo(d.name);
    }

}

You could then use it any where in your code where you would like to compare dogs as follows:

// Sorts the array list using comparator
Collections.sort(list, Dog.DESCENDING_COMPARATOR);

Another important thing to remember when implementing Comparable is that it is important that compareTo performs consistently with equals. Although it is not required, failing to do so could result in strange behaviour on some collections such as some implementations of Sets. See this post for more information on sound principles of implementing compareTo.

Update 2: Chris is right, this code is susceptible to overflows for large negative values of age. The correct way to implement this in Java 7 and up would be Integer.compare(d.age, d1.age) instead of d.age - d1.age.

Update 3: With Java 8, your Comparator could be written a lot more succinctly as:

public static final Comparator<Dog> DESCENDING_COMPARATOR = 
    Comparator.comparing(Dog::getDogAge).reversed();

The syntax for Collections.sort stays the same, but compare can be written as

public int compare(Dog d, Dog d1) {
    return DESCENDING_COMPARATOR.compare(d, d1);
}

Can Rails Routing Helpers (i.e. mymodel_path(model)) be Used in Models?

Any logic having to do with what is displayed in the view should be delegated to a helper method, as methods in the model are strictly for handling data.

Here is what you could do:

# In the helper...

def link_to_thing(text, thing)
  (thing.url?) ? link_to(text, thing_path(thing)) : link_to(text, thing.url)
end

# In the view...

<%= link_to_thing("text", @thing) %>

Xcode source automatic formatting

In xcode, you can use this shortcut to Re-indent your source code

Go to file, which has indent issues, and follow this :

  • Cmd + A to select all source codes

  • Ctrl + I to re-indent

Hope this helps.

Passing a varchar full of comma delimited values to a SQL Server IN function

I can suggest using WITH like this:

DECLARE @Delim char(1) = ',';
SET @Ids = @Ids + @Delim;

WITH CTE(i, ls, id) AS (
    SELECT 1, CHARINDEX(@Delim, @Ids, 1), SUBSTRING(@Ids, 1, CHARINDEX(@Delim, @Ids, 1) - 1)
    UNION ALL
    SELECT i + 1, CHARINDEX(@Delim, @Ids, ls + 1), SUBSTRING(@Ids, ls + 1, CHARINDEX(@Delim, @Ids, ls + 1) - CHARINDEX(@Delim, @Ids, ls) - 1)
    FROM CTE
    WHERE  CHARINDEX(@Delim, @Ids, ls + 1) > 1
)
SELECT t.*
FROM yourTable t
    INNER JOIN
    CTE c
    ON t.id = c.id;

Codeigniter $this->db->order_by(' ','desc') result is not complete

Put from before where, and order_by on last:

$this->db->select('*');
$this->db->from('courses');
$this->db->where('tennant_id',$tennant_id);
$this->db->order_by("UPPER(course_name)","desc");

Or try BINARY:

ORDER BY BINARY course_name DESC;

You should add manually on codeigniter for binary sorting.

And set "course_name" character column.

If sorting is used on a character type column, normally the sort is conducted in a case-insensitive fashion.

What type of structure data in courses table?

If you frustrated you can put into array and return using PHP:

Use natcasesort for order in "natural order": (Reference: http://php.net/manual/en/function.natcasesort.php)

Your array from database as example: $array_db = $result_from_db:

$final_result = natcasesort($array_db);

print_r($final_result);

What is the difference between const int*, const int * const, and int const *?

Like pretty much everyone pointed out:

What’s the difference between const X* p, X* const p and const X* const p?

You have to read pointer declarations right-to-left.

  • const X* p means "p points to an X that is const": the X object can't be changed via p.

  • X* const p means "p is a const pointer to an X that is non-const": you can't change the pointer p itself, but you can change the X object via p.

  • const X* const p means "p is a const pointer to an X that is const": you can't change the pointer p itself, nor can you change the X object via p.

What causes java.lang.IncompatibleClassChangeError?

While these answers are all correct, resolving the problem is often more difficult. It's generally the result of two mildly different versions of the same dependency on the classpath, and is almost always caused by either a different superclass than was originally compiled against being on the classpath or some import of the transitive closure being different, but generally at class instantiation and constructor invocation. (After successful class loading and ctor invocation, you'll get NoSuchMethodException or whatnot.)

If the behavior appears random, it's likely the result of a multithreaded program classloading different transitive dependencies based on what code got hit first.

To resolve these, try launching the VM with -verbose as an argument, then look at the classes that were being loaded when the exception occurs. You should see some surprising information. For instance, having multiple copies of the same dependency and versions you never expected or would have accepted if you knew they were being included.

Resolving duplicate jars with Maven is best done with a combination of the maven-dependency-plugin and maven-enforcer-plugin under Maven (or SBT's Dependency Graph Plugin, then adding those jars to a section of your top-level POM or as imported dependency elements in SBT (to remove those dependencies).

Good luck!

how to check if input field is empty

Try this

$.trim($("#spa").val()).length > 0

It will not treat any white space if any as a correct value

Shortcut to create properties in Visual Studio?

If you are using Visual Studio 2013, 2015 or above, just click the link below. It will give you the full shortcuts in Visual Studio!

Visual C# Code Snippets

Android "hello world" pushnotification example

Update 2016:

GCM is being replaced with FCM

Update 2015:

Have a look at developers.android.com - Google replaced C2DM with GCM Demo Implementation / How To

Update 2014:

1) You need to check on the server what HTTP response you are getting from the Google servers. Make sure it is a 200 OK response, so you know the message was sent. If you get another response (302, etc) then the message is not being sent successfully.

2) You also need to check that the Registration ID you are using is correct. If you provide the wrong Registration ID (as a destination for the message - specifying the app, on a specific device) then the Google servers cannot successfully send it.

3) You also need to check that your app is successfully registering with the Google servers, to receive push notifications. If the registration fails, you will not receive messages.

First Answer 2014

Here is a good question you may should have a look at it: How to add a push notification in my own android app

Also here is a good blog with a really simple how to: http://blog.serverdensity.com/android-push-notifications-tutorial/

How to check the exit status using an if statement

Alternative to explicit if statement

Minimally:

test $? -eq 0 || echo "something bad happened"

Complete:

EXITCODE=$?
test $EXITCODE -eq 0 && echo "something good happened" || echo "something bad happened"; 
exit $EXITCODE