How to dynamically change the color of the selected menu item of a web page?

At last I managed to achieve what I intended with all your help and the post Change a link style onclick. Here is the code for that. I used JavaScript for doing this.

<html>
    <head>
        <style type="text/css">
            .item {
                width:900px;
                padding:0;
                margin:0;
                list-style-type:none;
            }

            a {
                display:block;
                width:60;
                line-height:25px; /*24px*/
                border-bottom:1px  none #808080;
                font-family:'arial narrow',sans-serif;
                color:#00F;
                text-align:center;
                text-decoration:none;
                background:#CCC;
                border-radius: 5px;
                -webkit-border-radius: 5px;
                -moz-border-radius: 5px;
                margin-bottom:0em;
                padding: 0px;
            }

            a.item {
                float:left;        /* For horizontal left to right display. */
                width:145px;       /* For maintaining equal  */
                margin-right: 5px; /* space between two boxes. */
            }

            a.selected{
                background:orange;
                color:white;
            }
        </style>
    </head>
    <body>
        <a class="item" href="#" >item 1</a>
        <a class="item" href="#" >item 2</a>
        <a class="item" href="#" >item 3</a>
        <a class="item" href="#" >item 4</a>
        <a class="item" href="#" >item 5</a>
        <a class="item" href="#" >item 6</a>

        <script>
            var anchorArr=document.getElementsByTagName("a");
            var prevA="";
            for(var i=0;i<anchorArr.length;i++)
            {
                anchorArr[i].onclick = function(){
                    if(prevA!="" && prevA!=this)
                    {
                        prevA.className="item";
                    }
                    this.className="item selected";
                    prevA=this;
                }
            }
        </script>
    </body>
</html>

How to convert a boolean array to an int array

A funny way to do this is

>>> np.array([True, False, False]) + 0 
np.array([1, 0, 0])

How do I convert a Python program to a runnable .exe Windows program?

For this you have two choices:

A downgrade to python 2.6. This is generally undesirable because it is backtracking and may nullify a small portion of your scripts
Your second option is to use some form of exe converter. I recommend pyinstaller as it seems to have the best results.

How to receive serial data using android bluetooth

The issue with the null connection is related to the findBT() function. you must change the device name from "MattsBlueTooth" to your device name as well as confirm the UUID for your service/device. Use something like BLEScanner app to confrim both on Android.

Can you do a partial checkout with Subversion?

Sort of. As Bobby says:

svn co file:///.../trunk/foo file:///.../trunk/bar file:///.../trunk/hum

will get the folders, but you will get separate folders from a subversion perspective. You will have to go separate commits and updates on each subfolder.

I don't believe you can checkout a partial tree and then work with the partial tree as a single entity.

Offset a background image from the right using CSS

!! Outdated answer, since CSS3 brought this feature

Is there a way to position a background image a certain number of pixels from the right of its element?

Nope.

Popular workarounds include

setting a margin-right on the element instead
adding transparent pixels to the image itself and positioning it top right
or calculating the position using jQuery after the element's width is known.

Java: String - add character n-times

 String toAdd = "toAdd";
 StringBuilder s = new StringBuilder();
 for(int count = 0; count < MAX; count++) {
     s.append(toAdd);
  }
  String output = s.toString();

Entity Framework 6 Code first Default value

I admit that my approach escapes the whole "Code First" concept. But if you have the ability to just change the default value in the table itself... it's much simpler than the lengths that you have to go through above... I'm just too lazy to do all that work!

It almost seems as if the posters original idea would work:

[DefaultValue(true)]
public bool IsAdmin { get; set; }

I thought they just made the mistake of adding quotes... but alas no such intuitiveness. The other suggestions were just too much for me (granted I have the privileges needed to go into the table and make the changes... where not every developer will in every situation). In the end I just did it the old fashioned way. I set the default value in the SQL Server table... I mean really, enough already! NOTE: I further tested doing an add-migration and update-database and the changes stuck.

ruby 1.9: invalid byte sequence in UTF-8

This seems to work:

def sanitize_utf8(string)
  return nil if string.nil?
  return string if string.valid_encoding?
  string.chars.select { |c| c.valid_encoding? }.join
end

Silent installation of a MSI package

You should be able to use the /quiet or /qn options with msiexec to perform a silent install.

MSI packages export public properties, which you can set with the PROPERTY=value syntax on the end of the msiexec parameters.

For example, this command installs a package with no UI and no reboot, with a log and two properties:

msiexec /i c:\path\to\package.msi /quiet /qn /norestart /log c:\path\to\install.log PROPERTY1=value1 PROPERTY2=value2

You can read the options for msiexec by just running it with no options from Start -> Run.

How to use a different version of python during NPM install?

This one works better if you don't have the python on path or want to specify the directory :

//for Windows
npm config set python C:\Python27\python.exe

//for Linux
npm config set python /usr/bin/python27

Mockito matcher and array of primitives

I would rather use Matchers.<byte[]>any(). This worked for me.

Call web service in excel

Yes You Can!

I worked on a project that did that (see comment). Unfortunately no code samples from that one, but googling revealed these:

How you can integrate data from several Web services using Excel and VBA

STEP BY STEP: Consuming Web Services through VBA (Excel or Word)

VBA: Consume Soap Web Services

Deprecation warning in Moment.js - Not in a recognized ISO format

This answer is to give a better understanding of this warning

Deprecation warning is caused when you use moment to create time object, var today = moment();.

If this warning is okay with you then I have a simpler method.

Don't use date object from js use moment instead. For example use moment() to get the current date.

Or convert the js date object to moment date. You can simply do that specifying the format of your js date object.

ie, moment("js date", "js date format");

eg:

moment("2014 04 25", "YYYY MM DD");

(BUT YOU CAN ONLY USE THIS METHOD UNTIL IT'S DEPRECIATED, this may be depreciated from moment in the future)

Search for exact match of string in excel row using VBA Macro

Never mind, I found the answer.

This will do the trick.

Dim colIndex As Long    
colIndex = Application.Match(colName, Range(Cells(rowIndex, 1), Cells(rowIndex, 100)), 0)

Can I scroll a ScrollView programmatically in Android?

**to scroll up to desired height. I have come up with some good solution **

                scrollView.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        scrollView.scrollBy(0, childView.getHeight());
                    }
                }, 100);

How can I calculate the time between 2 Dates in typescript

Use the getTime method to get the time in total milliseconds since 1970-01-01, and subtract those:

var time = new Date().getTime() - new Date("2013-02-20T12:01:04.753Z").getTime();

Set font-weight using Bootstrap classes

Create in your Site.css (or in another place) a new class named for example .font-bold and set it to your element

.font-bold {
  font-weight: bold;
}

How to type a new line character in SQL Server Management Studio

You can paste the lines in from a text editor that uses UNIX-style line endings (CR+LF). I use Notepad++. First go to Settings/Preferences/New Document and change the format from Windows to Unix. Then open a new document, type in your lines, and copy them into SSMS.

What is difference between Lightsail and EC2?

I think the lightsail as the name suggest is light weight and meant for initial development. For production sites and apps with high volume it simply becomes unavailable and hangs....It is just a sandbox to play with things. Further lack of support reduces its reliability. There should be an option to migrate to EC2, when u fully develop your apps or sites..So that with same minimum configuration you can migrate to scalable EC2..

PostgreSQL Autoincrement

Since PostgreSQL 10

CREATE TABLE test_new (
    id int GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
    payload text
);

Should a function have only one return statement?

Multiple exit is good if you manage it well

The first step is to specify the reasons of exit. Mine is usually something like this:
1. No need to execute the function
2. Error is found
3. Early completion
4. Normal completion
I suppose you can group "1. No need to execute the function" into "3. Early completion" (a very early completion if you will).

The second step is to let the world outside the function know the reason of exit. The pseudo-code looks something like this:

function foo (input, output, exit_status)

  exit_status == UNDEFINED
  if (check_the_need_to_execute == false) then
    exit_status = NO_NEED_TO_EXECUTE  // reason #1 
    exit

  useful_work

  if (error_is_found == true) then
    exit_status = ERROR               // reason #2
    exit
  if (need_to_go_further == false) then
    exit_status = EARLY_COMPLETION    // reason #3
    exit

  more_work

  if (error_is_found == true) then
    exit_status = ERROR
  else
    exit_status = NORMAL_COMPLETION   // reason #4

end function

Obviously, if it's beneficial to move a lump of work in the illustration above into a separate function, you should do so.

If you want to, you can be more specific with the exit status, say, with several error codes and early completion codes to pinpoint the reason (or even the location) of exit.

Even if you force this function into one that has only a single exit, I think you still need to specify exit status anyway. The caller needs to know whether it's OK to use the output, and it helps maintenance.

Importing larger sql files into MySQL

If you are using the source command on Windows remember to use f:/myfolder/mysubfolder/file.sql and not f:\myfolder\mysubfolder\file.sql

Get the records of last month in SQL server

I'm from Oracle env and I would do it like this in Oracle:

select * from table
where trunc(somedatefield, 'MONTH') =
trunc(sysdate -INTERVAL '0-1' YEAR TO MONTH, 'MONTH')

Idea: I'm running a scheduled report of previous month (from day 1 to the last day of the month, not windowed). This could be index unfriendly, but Oracle has fast date handling anyways. Is there a similar simple and short way in MS SQL? The answer comparing year and month separately seems silly to Oracle folks.

How do I set the visibility of a text box in SSRS using an expression?

=IIf((CountRows("ScannerStatisticsData")=0),False,True)

Should be replaced with

=IIf((CountRows("ScannerStatisticsData")=0),True,False)

because the Visibility expression set up the Hidden value.

Python TypeError must be str not int

you need to cast int to str before concatenating. for that use str(temperature). Or you can print the same output using , if you don't want to convert like this.

print("the furnace is now",temperature , "degrees!")

pull/push from multiple remote locations

I added these aliases to my ~/.bashrc:

alias pushall='for i in `git remote`; do git push $i; done;'
alias pullall='for i in `git remote`; do git pull $i; done;'

TypeError: cannot perform reduce with flexible type

It looks like your 'trainData' is a list of strings:

['-214' '-153' '-58' ..., '36' '191' '-37']

Change your 'trainData' to a numeric type.

 import numpy as np
 np.array(['1','2','3']).astype(np.float)

How to center a table of the screen (vertically and horizontally)

I think this should do the trick:

<table border="1px" align="center">

According to http://w3schools.com/tags/tag_table.asp this is deprecated, but try it. If it does not work, go for styles, as mentioned on the site.

In OS X Lion, LANG is not set to UTF-8, how to fix it?

if you have zsh installed you can also update ~/.zprofile with

if [[ -z "$LC_ALL" ]]; then
  export LC_ALL='en_US.UTF-8'
fi

and check the output using the locale cmd as show above

? locale                                                                                                                                           
LANG="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_CTYPE="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_ALL="en_US.UTF-8"

Adding gif image in an ImageView in android

I would suggest you to use Glide library. To use Glide you need to add this to add these dependencies

compile 'com.github.bumptech.glide:glide:3.7.0'
compile 'com.android.support:support-v4:23.4.0'

to your grandle (Module:app) file.

Then use this line of code to load your gif image

Glide.with(context).load(R.drawable.loading).asGif().diskCacheStrategy(DiskCacheStrategy.SOURCE).crossFade().into(loadingImageView);

More Information on Glide

Using global variables between files?

See Python's document on sharing global variables across modules:

The canonical way to share information across modules within a single program is to create a special module (often called config or cfg).

config.py:
x = 0   # Default value of the 'x' configuration setting
Import the config module in all modules of your application; the module then becomes available as a global name.

main.py:
import config
print (config.x)
or
from config import x
print (x)

In general, don’t use from modulename import *. Doing so clutters the importer’s namespace, and makes it much harder for linters to detect undefined names.

UTF-8 problems while reading CSV file with fgetcsv

Try putting this into the top of your file (before any other output):

<?php

header('Content-Type: text/html; charset=UTF-8');

?>

how to end ng serve or firebase serve

With Windows 10 / Powershell ctrl + c did not work; Powershell tried to gracefully stop the app.

Used normal cmd and had no issues stopping the ng serve with ctrl + c.

How to initialise memory with new operator in C++?

For c++ use std::array<int/*type*/, 10/*size*/> instead of c-style array. This is available with c++11 standard, and which is a good practice. See it here for standard and examples. If you want to stick to old c-style arrays for reasons, there two possible ways:

int *a = new int[5](); Here leave the parenthesis empty, otherwise it will give compile error. This will initialize all the elements in the allocated array. Here if you don't use the parenthesis, it will still initialize the integer values with zeros because new will call the constructor, which is in this case int().
int *a = new int[5] {0, 0, 0}; This is allowed in c++11 standard. Here you can initialize array elements with any value you want. Here make sure your initializer list(values in {}) size should not be greater than your array size. Initializer list size less than array size is fine. Remaining values in array will be initialized with 0.

Change Row background color based on cell value DataTable

This is how managed to change my data table row background (DataTables 1.10.19)

$('#memberList').DataTable({
    "processing": true,
    "serverSide": true,
    "pageLength":25,
    "ajax":{
        "dataType": "json",
        "type": "POST",
        "url": mainUrl+"/getMember",
       },
    "columns": [
        { "data": "id" },
        { "data": "name" },
        { "data": "email" },
        { "data": "phone" },
        { "data": "country_id" },
        { "data": "created_at" },
        { "data": "action" },
    ],
    "fnRowCallback": function( nRow, aData, iDisplayIndex, iDisplayIndexFull ) {
        switch(aData['country_id']){
            case 1:
                $('td', nRow).css('background-color', '#dacfcf')
                break;
        }
    }
});

You can use fnRowCallback method function to change the background.

Git error: "Host Key Verification Failed" when connecting to remote repository

If you are in office intranet (otherwise dangerous) which is always protected by firewalls simply have the following lines in your ~/.ssh/config.

Host *
  StrictHostKeyChecking no
  UserKnownHostsFile=/dev/null

Compare two Lists for differences

.... but how do we find the equivalent class in the second List to pass to the method below;

This is your actual problem; you must have at least one immutable property, a id or something like that, to identify corresponding objects in both lists. If you do not have such a property you, cannot solve the problem without errors. You can just try to guess corresponding objects by searching for minimal or logical changes.

If you have such an property, the solution becomes really simple.

Enumerable.Join(
   listA, listB,
   a => a.Id, b => b.Id,
   (a, b) => CompareTwoClass_ReturnDifferences(a, b))

thanks to you both danbruc and Noldorin for your feedback. both Lists will be the same length and in the same order. so the method above is close, but can you modify this method to pass the enum.Current to the method i posted above?

Now I am confused ... what is the problem with that? Why not just the following?

for (Int32 i = 0; i < Math.Min(listA.Count, listB.Count); i++)
{
    yield return CompareTwoClass_ReturnDifferences(listA[i], listB[i]);
}

The Math.Min() call may even be left out if equal length is guaranted.

Noldorin's implementation is of course smarter because of the delegate and the use of enumerators instead of using ICollection.

Create normal zip file programmatically

My 2 cents:

    using (ZipArchive archive = ZipFile.Open(zFile, ZipArchiveMode.Create))
    {
        foreach (var fPath in filePaths)
        {
            archive.CreateEntryFromFile(fPath,Path.GetFileName(fPath));
        }
    }

So Zip files could be created directly from files/dirs.

An internal error occurred during: "Updating Maven Project". java.lang.NullPointerException

org.eclipse.m2e.core.prefs file is in .settings folder. If you face the problem of

An internal error occurred during: "Updating Maven Project". java.lang.NullPointerException

Delete the project from eclipse then by deleting the .settings folder & .project file in the project -> then re-import the project.

Git pushing to remote branch

You can push your local branch to a new remote branch like so:

git push origin master:test

(Assuming origin is your remote, master is your local branch name and test is the name of the new remote branch, you wish to create.)

If at the same time you want to set up your local branch to track the newly created remote branch, you can do so with -u (on newer versions of Git) or --set-upstream, so:

git push -u origin master:test

git push --set-upstream origin master:test

...will create a new remote branch, named test, in remote repository origin, based on your local master, and setup your local master to track it.

using .join method to convert array to string without commas

All you need to do is :

arr.join('');

FIDDLE

How do I access call log for android?

Use Below code:

private void getCallDeatils() {
    StringBuffer stringBuffer = new StringBuffer();
    Cursor managedCursor = getActivity().managedQuery(CallLog.Calls.CONTENT_URI, null, null, null, null);
    int number = managedCursor.getColumnIndex(CallLog.Calls.NUMBER);
    int type = managedCursor.getColumnIndex(CallLog.Calls.TYPE);
    int date = managedCursor.getColumnIndex(CallLog.Calls.DATE);

    int duration = managedCursor.getColumnIndex(CallLog.Calls.DURATION);
    stringBuffer.append("Call Deatils");
    while (managedCursor.moveToNext()) {
        String phNumber = managedCursor.getString(number);
        String callType = managedCursor.getString(type);
        String callDate = managedCursor.getString(date);
        Date callDayTime = new Date(Long.valueOf(callDate));
        DateFormat df = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
        String reportDate = df.format(callDayTime);
        String callDuration = managedCursor.getString(duration);
        String dir = null;
        int dircode = Integer.parseInt(callType);
        switch (dircode) {
            case CallLog.Calls.OUTGOING_TYPE:
                dir = "OUTGOING";
                break;

            case CallLog.Calls.INCOMING_TYPE:
                dir = "INCOMING";

                break;

            case CallLog.Calls.MISSED_TYPE:
                dir = "MISSED";
                break;

        }
        stringBuffer.append("\nPhone Number:--- " + phNumber + " \nCall Type:--- " + dir + " \nCall Date:--- " +callDate + " \nCall duration in sec :--- " + callDuration);
        stringBuffer.append("\n----------------------------------");

        logs.add(new LogClass(phNumber,dir,reportDate,callDuration));




    }

git is not installed or not in the PATH

Installing git and running npm install from git-bash worked for me. Make sure you are in the correct directory.

Sort a list of tuples by 2nd item (integer value)

For a lambda-avoiding method, first define your own function:

def MyFn(a):
    return a[1]

then:

sorted([('abc', 121),('abc', 231),('abc', 148), ('abc',221)], key=MyFn)

change array size

Used this approach for array of bytes:

Initially:

byte[] bytes = new byte[0];

Whenever required (Need to provide original length for extending):

Array.Resize<byte>(ref bytes, bytes.Length + requiredSize);

Reset:

Array.Resize<byte>(ref bytes, 0);

Typed List Method

Initially:

List<byte> bytes = new List<byte>();

Whenever required:

bytes.AddRange(new byte[length]);

Release/Clear:

bytes.Clear()

How do I change button size in Python?

I've always used .place() for my tkinter widgets. place syntax

You can specify the size of it just by changing the keyword arguments!

Of course, you will have to call .place() again if you want to change it.

Works in python 3.8.2, if you're wondering.

TypeError: 'in <string>' requires string as left operand, not int

You simply need to make cab a string:

cab = '6176'

As the error message states, you cannot do <int> in <string>:

>>> 1 in '123'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'in <string>' requires string as left operand, not int
>>>

because integers and strings are two totally different things and Python does not embrace implicit type conversion ("Explicit is better than implicit.").

In fact, Python only allows you to use the in operator with a right operand of type string if the left operand is also of type string:

>>> '1' in '123'  # Works!
True
>>>
>>> [] in '123'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'in <string>' requires string as left operand, not list
>>>
>>> 1.0 in '123'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'in <string>' requires string as left operand, not float
>>>
>>> {} in '123'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'in <string>' requires string as left operand, not dict
>>>

restart mysql server on windows 7

use net stop mysql57 instead, it should be the version that is not specified

How to sort a list of lists by a specific index of the inner list?

Like this:

import operator
l = [...]
sorted_list = sorted(l, key=operator.itemgetter(desired_item_index))

How to add minutes to my Date

Just for anybody who is interested. I was working on an iOS project that required similar functionality so I ended porting the answer by @jeznag to swift

private func addMinutesToDate(minutes: Int, beforeDate: NSDate) -> NSDate {
    var SIXTY_SECONDS = 60

    var m = (Double) (minutes * SIXTY_SECONDS)
    var c =  beforeDate.timeIntervalSince1970  + m
    var newDate = NSDate(timeIntervalSince1970: c)

    return newDate
}

rake assets:precompile RAILS_ENV=production not working as required

Have you added this gem to your gemfile?

# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'

move that gem out of assets group and then run bundle again, I hope that would help!

Get query string parameters url values with jQuery / Javascript (querystring)

Why extend jQuery? What would be the benefit of extending jQuery vs just having a global function?

function qs(key) {
    key = key.replace(/[*+?^$.\[\]{}()|\\\/]/g, "\\$&"); // escape RegEx meta chars
    var match = location.search.match(new RegExp("[?&]"+key+"=([^&]+)(&|$)"));
    return match && decodeURIComponent(match[1].replace(/\+/g, " "));
}

http://jsfiddle.net/gilly3/sgxcL/

An alternative approach would be to parse the entire query string and store the values in an object for later use. This approach doesn't require a regular expression and extends the window.location object (but, could just as easily use a global variable):

location.queryString = {};
location.search.substr(1).split("&").forEach(function (pair) {
    if (pair === "") return;
    var parts = pair.split("=");
    location.queryString[parts[0]] = parts[1] &&
        decodeURIComponent(parts[1].replace(/\+/g, " "));
});

http://jsfiddle.net/gilly3/YnCeu/

This version also makes use of Array.forEach(), which is unavailable natively in IE7 and IE8. It can be added by using the implementation at MDN, or you can use jQuery's $.each() instead.

Postgres password authentication fails

Assuming, that you have root access on the box you can do:

sudo -u postgres psql

If that fails with a database "postgres" does not exists this block.

sudo -u postgres psql template1

Then sudo nano /etc/postgresql/11/main/pg_hba.conf file

local   all         postgres                          ident

For newer versions of PostgreSQL ident actually might be peer.

Inside the psql shell you can give the DB user postgres a password:

ALTER USER postgres PASSWORD 'newPassword';

Last executed queries for a specific database

This works for me to find queries on any database in the instance. I'm sysadmin on the instance (check your privileges):

SELECT deqs.last_execution_time AS [Time], dest.text AS [Query], dest.*
FROM sys.dm_exec_query_stats AS deqs
CROSS APPLY sys.dm_exec_sql_text(deqs.sql_handle) AS dest
WHERE dest.dbid = DB_ID('msdb')
ORDER BY deqs.last_execution_time DESC

This is the same answer that Aaron Bertrand provided but it wasn't placed in an answer.

How do I align views at the bottom of the screen?

This can be done with a linear layout too.

Just provide Height = 0dp and weight = 1 to the layout above and the one you want in the bottom. Just write height = wrap content and no weight.

It provides wrap content for the layout (the one that contains your edit text and button) and then the one that has weight occupies the rest of the layout.

I discovered this by accident.

Output an Image in PHP

    $file = '../image.jpg';
    $type = 'image/jpeg';
    header('Content-Type:'.$type);
    header('Content-Length: ' . filesize($file));
    $img = file_get_contents($file);
    echo $img;

This is works for me! I have test it on code igniter. if i use readfile, the image won't display. Sometimes only display jpg, sometimes only big file. But after i changed it to "file_get_contents" , I get the flavour, and works!! this is the screenshoot: Screenshot of "secure image" from database

How to add buttons dynamically to my form?

use button array like this.it will create 3 dynamic buttons bcoz h variable has value of 3

private void button1_Click(object sender, EventArgs e)
{
int h =3;


Button[] buttonArray = new Button[8];

for (int i = 0; i <= h-1; i++)
{
   buttonArray[i] = new Button();
   buttonArray[i].Size = new Size(20, 43);
   buttonArray[i].Name= ""+i+"";
   buttonArray[i].Click += button_Click;//function
   buttonArray[i].Location = new Point(40, 20 + (i * 20));
    panel1.Controls.Add(buttonArray[i]);

}  }

jQuery select2 get value of select tag?

This solution allows you to forget select element. Helpful when you do not have an id on select elements.

$("#first").select2()
.on("select2:select", function (e) {
    var selected_element = $(e.currentTarget);
    var select_val = selected_element.val();
});

How do I limit the number of decimals printed for a double?

Formatter class is also a good option. fmt.format("%.2f", variable); 2 here is showing how many decimals you want. You can change it to 4 for example. Don't forget to close the formatter.

 private static int nJars, nCartons, totalOunces, OuncesTolbs, lbs;

 public static void main(String[] args)
  {
   computeShippingCost();
  }

  public static void computeShippingCost()
  {
   System.out.print("Enter a number of jars: ");
   Scanner kboard = new Scanner (System.in);
   nJars = kboard.nextInt();
   int nCartons = (nJars + 11) / 12;
   int totalOunces = (nJars * 21) + (nCartons * 25);
   int lbs = totalOunces / 16;


   double shippingCost =  ((nCartons * 1.44) + (lbs + 1) * 0.96) + 3.0;

     Formatter fmt = new Formatter();
     fmt.format("%.2f", shippingCost);

   System.out.print("$" + fmt);

   fmt.close();

}

Inverse of matrix in R

solve(c) does give the correct inverse. The issue with your code is that you are using the wrong operator for matrix multiplication. You should use solve(c) %*% c to invoke matrix multiplication in R.

R performs element by element multiplication when you invoke solve(c) * c.

Return background color of selected cell

You can use Cell.Interior.Color, I've used it to count the number of cells in a range that have a given background color (ie. matching my legend).

How to set image to UIImage

UIImage *img = [UIImage imageNamed:@"anyImageName"];

imageNamed:
Returns the image object associated with the specified filename.
    + (UIImage *)imageNamed:(NSString *)name
Parameters
name
The name of the file. If this is the first time the image is being loaded, the method looks for an image with the specified name in the application’s main bundle.
Return Value
The image object for the specified file, or nil if the method could not find the specified image.

Discussion
This method looks in the system caches for an image object with the specified name and returns that object if it exists. If a matching image object is not already in the cache, this method loads the image data from the specified file, caches it, and then returns the resulting object.

How to convert int to float in python?

In Python 3 this is the default behavior, but if you aren't using that you can import division like so:

>>> from __future__ import division
>>> 144/314
0.4585987261146497

Alternatively you can cast one of the variables to a float when doing your division which will do the same thing

sum = 144
women_onboard = 314
proportion_womenclass3_survived = sum / float(np.size(women_onboard))

Django - after login, redirect user to his custom page --> mysite.com/username

A simpler approach relies on redirection from the page LOGIN_REDIRECT_URL. The key thing to realize is that the user information is automatically included in the request.

Suppose:

LOGIN_REDIRECT_URL = '/profiles/home'

and you have configured a urlpattern:

(r'^profiles/home', home),

Then, all you need to write for the view home() is:

from django.http import HttpResponseRedirect
from django.urls import reverse
from django.contrib.auth.decorators import login_required

@login_required
def home(request):
    return HttpResponseRedirect(
               reverse(NAME_OF_PROFILE_VIEW, 
                       args=[request.user.username]))

where NAME_OF_PROFILE_VIEW is the name of the callback that you are using. With django-profiles, NAME_OF_PROFILE_VIEW can be 'profiles_profile_detail'.

Python class inherits object

History from Learn Python the Hard Way:

Python's original rendition of a class was broken in many serious ways. By the time this fault was recognized it was already too late, and they had to support it. In order to fix the problem, they needed some "new class" style so that the "old classes" would keep working but you can use the new more correct version.

They decided that they would use a word "object", lowercased, to be the "class" that you inherit from to make a class. It is confusing, but a class inherits from the class named "object" to make a class but it's not an object really its a class, but don't forget to inherit from object.

Also just to let you know what the difference between new-style classes and old-style classes is, it's that new-style classes always inherit from object class or from another class that inherited from object:

class NewStyle(object):
    pass

Another example is:

class AnotherExampleOfNewStyle(NewStyle):
    pass

While an old-style base class looks like this:

class OldStyle():
    pass

And an old-style child class looks like this:

class OldStyleSubclass(OldStyle):
    pass

You can see that an Old Style base class doesn't inherit from any other class, however, Old Style classes can, of course, inherit from one another. Inheriting from object guarantees that certain functionality is available in every Python class. New style classes were introduced in Python 2.2

How to get the Parent's parent directory in Powershell?

In powershell :

$this_script_path = $(Get-Item $($MyInvocation.MyCommand.Path)).DirectoryName

$parent_folder = Split-Path $this_script_path -Leaf

How to change maximum number of POST variable in PHP?

Codeigniter - no input file specified

Godaddy hosting it seems fixed on .htaccess, myself it is working

RewriteRule ^(.*)$ index.php/$1 [L]

RewriteRule ^(.*)$ index.php?/$1 [QSA,L]

No Access-Control-Allow-Origin header is present on the requested resource

I find the solution in spring.io,like this:

    response.setHeader("Access-Control-Allow-Origin", "*");
    response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
    response.setHeader("Access-Control-Max-Age", "3600");
    response.setHeader("Access-Control-Allow-Headers", "x-requested-with");

IntelliJ - Convert a Java project/module into a Maven project/module

I had a different scenario, but still landed on this answer.
I had imported my root project folder containing multiple Maven projects but also some other stuff used in this project.
IntelliJ recognised the Java files, but didn't resolve the Maven dependencies.

I fixed this by performing a right-click on each pom and then "Add as maven project"

String method cannot be found in a main class method

It seem like your Resort method doesn't declare a compareTo method. This method typically belongs to the Comparable interface. Make sure your class implements it.

Additionally, the compareTo method is typically implemented as accepting an argument of the same type as the object the method gets invoked on. As such, you shouldn't be passing a String argument, but rather a Resort.

Alternatively, you can compare the names of the resorts. For example

if (resortList[mid].getResortName().compareTo(resortName)>0)

ERROR: Cannot open source file " "

One thing that caught me out and surprised me was, in an inherited project, the files it was referring to were referred to on a relative path outside of the project folder but yet existed in the project folder.

In solution explorer, single click each file with the error, bring up the Properties window (right-click, Properties), and ensure the "Relative Path" is just the file name (e.g. MyMissingFile.cpp) if it is in the project folder. In my case it was set to: ..\..\Some Other Folder\MyMissingFile.cpp.

How can two strings be concatenated?

paste()

is the way to go. As the previous posters pointed out, paste can do two things:

concatenate values into one "string", e.g.

> paste("Hello", "world", sep=" ")
[1] "Hello world"

where the argument sep specifies the character(s) to be used between the arguments to concatenate, or collapse character vectors

> x <- c("Hello", "World")
> x
[1] "Hello" "World"
> paste(x, collapse="--")
[1] "Hello--World"

where the argument collapse specifies the character(s) to be used between the elements of the vector to be collapsed.

You can even combine both:

> paste(x, "and some more", sep="|-|", collapse="--")
[1] "Hello|-|and some more--World|-|and some more"

Hope this helps.

'Incomplete final line' warning when trying to read a .csv file into R

The message indicates that the last line of the file doesn't end with an End Of Line (EOL) character (linefeed (\n) or carriage return+linefeed (\r\n)). The original intention of this message was to warn you that the file may be incomplete; most datafiles have an EOL character as the very last character in the file.

The remedy is simple:

Open the file
Navigate to the very last line of the file
Place the cursor the end of that line
Press return
Save the file

Disable back button in android

You can override the onBackPressed() method in your activity and remove the call to super class.

@Override
public void onBackPressed() {
  //remove call to the super class
  //super.onBackPressed();
}

PDO get the last ID inserted

lastInsertId() only work after the INSERT query.

Correct:

$stmt = $this->conn->prepare("INSERT INTO users(userName,userEmail,userPass) 
                              VALUES(?,?,?);");
$sonuc = $stmt->execute([$username,$email,$pass]);
$LAST_ID = $this->conn->lastInsertId();

Incorrect:

$stmt = $this->conn->prepare("SELECT * FROM users");
$sonuc = $stmt->execute();
$LAST_ID = $this->conn->lastInsertId(); //always return string(1)=0

Pass Additional ViewData to a Strongly-Typed Partial View

RenderPartial takes another parameter that is simply a ViewDataDictionary. You're almost there, just call it like this:

Html.RenderPartial(
      "ProductImageForm", 
       image, 
       new ViewDataDictionary { { "index", index } }
);

Note that this will override the default ViewData that all your other Views have by default. If you are adding anything to ViewData, it will not be in this new dictionary that you're passing to your partial view.

How to get the current date and time

import java.util.Date;   
Date now = new Date();

Note that the Date object is mutable and if you want to do anything sophisticated, use jodatime.

How to silence output in a Bash script?

If you are still struggling to find an answer, specially if you produced a file for the output, and you prefer a clear alternative: echo "hi" | grep "use this hack to hide the oputut :) "

R: numeric 'envir' arg not of length one in predict()

There are several problems here:

The newdata argument of predict() needs a predictor variable. You should thus pass it values for Coupon, instead of Total, which is the response variable in your model.
The predictor variable needs to be passed in as a named column in a data frame, so that predict() knows what the numbers its been handed represent. (The need for this becomes clear when you consider more complicated models, having more than one predictor variable).
For this to work, your original call should pass df in through the data argument, rather than using it directly in your formula. (This way, the name of the column in newdata will be able to match the name on the RHS of the formula).

With those changes incorporated, this will work:

model <- lm(Total ~ Coupon, data=df)
new <- data.frame(Coupon = df$Coupon)
predict(model, newdata = new, interval="confidence")

XML serialization in Java?

If you're talking about automatic XML serialization of objects, check out Castor:

Castor is an Open Source data binding framework for Java[tm]. It's the shortest path between Java objects, XML documents and relational tables. Castor provides Java-to-XML binding, Java-to-SQL persistence, and more.

JQuery datepicker not working

For me.. the problem was that the anchor needs a title, and that was missing!

How to do case insensitive search in Vim

put this command in your vimrc file

set ic

always do case insensitive search

How do I get extra data from intent on Android?

If you are trying to get extra data in fragments then you can try using:

Place data using:

Bundle args = new Bundle();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER);

Get data using:

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {


  getArguments().getInt(ARG_SECTION_NUMBER);
  getArguments().getString(ARG_SECTION_STRING);
  getArguments().getBoolean(ARG_SECTION_BOOL);
  getArguments().getChar(ARG_SECTION_CHAR);
  getArguments().getByte(ARG_SECTION_DATA);

}

Specify a Root Path of your HTML directory for script links?

Just start it with a slash? This means root. As long as you're testing on a web server (e.g. localhost) and not a file system (e.g. C:) then that should be all you need to do.

CSS to select/style first word

Here's a bit of JavaScript and jQuery I threw together to wrap the first word of each paragraph with a <span> tag.

$(function() {
    $('#content p').each(function() {
        var text = this.innerHTML;
        var firstSpaceIndex = text.indexOf(" ");
        if (firstSpaceIndex > 0) {
            var substrBefore = text.substring(0,firstSpaceIndex);
            var substrAfter = text.substring(firstSpaceIndex, text.length)
            var newText = '<span class="firstWord">' + substrBefore + '</span>' + substrAfter;
            this.innerHTML = newText;
        } else {
            this.innerHTML = '<span class="firstWord">' + text + '</span>';
        }
    });
});

You can then use CSS to create a style for .firstWord.

It's not perfect, as it doesn't account for every type of whitespace; however, I'm sure it could accomplish what you're after with a few tweaks.

Keep in mind that this code will only execute after page load, so it may take a split second to see the effect.

How to check for changes on remote (origin) Git repository

git remote update && git status

Found this on the answer to Check if pull needed in Git

git remote update to bring your remote refs up to date. Then you can do one of several things, such as:

git status -uno will tell you whether the branch you are tracking is ahead, behind or has diverged. If it says nothing, the local and remote are the same.

git show-branch *master will show you the commits in all of the branches whose names end in master (eg master and origin/master).

If you use -v with git remote update you can see which branches got updated, so you don't really need any further commands.

How to prevent vim from creating (and leaving) temporary files?

; For Windows Users to back to temp directory

set backup
set backupdir=C:\WINDOWS\Temp
set backupskip=C:\WINDOWS\Temp\*
set directory=C:\WINDOWS\Temp
set writebackup

How do I make a dotted/dashed line in Android?

For a Dotted effect on a Canvas, set this attribute to the paint object :

paint.setPathEffect(new DashPathEffect(new float[] {0,30}, 0));

And change the value 30 as your render suits you : it represents the "distance" between each dots.

Could not resolve all dependencies for configuration ':classpath'

For newer android studio 3.0.0 and gradle update, this needed to be included in project level build.gradle file for android Gradle build tools and related dependencies since Google moved to its own maven repository.

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()
        google()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'

        // NOTE: Do not place your application dependencies here; they belong
    }
}

allprojects {
    repositories {
        jcenter()
        google()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

How to fix warning from date() in PHP"

Try to set date.timezone in php.ini file. Or you can manually set it using ini_set() or date_default_timezone_set().

How can I remove a trailing newline?

workaround solution for special case:

if the newline character is the last character (as is the case with most file inputs), then for any element in the collection you can index as follows:

foobar= foobar[:-1]

to slice out your newline character.

How to place the "table" at the middle of the webpage?

The shortest and easiest answer is: you shouldn't vertically center things in webpages. HTML and CSS simply are not created with that in mind. They are text formatting languages, not user interface design languages.

That said, this is the best way I can think of. However, this will NOT WORK in Internet Explorer 7 and below!

<style>
  html, body {
    height: 100%;
  }
  #tableContainer-1 {
    height: 100%;
    width: 100%;
    display: table;
  }
  #tableContainer-2 {
    vertical-align: middle;
    display: table-cell;
    height: 100%;
  }
  #myTable {
    margin: 0 auto;
  }
</style>
<div id="tableContainer-1">
  <div id="tableContainer-2">
    <table id="myTable" border>
      <tr><td>Name</td><td>J W BUSH</td></tr>
      <tr><td>Proficiency</td><td>PHP</td></tr>
      <tr><td>Company</td><td>BLAH BLAH</td></tr>
    </table>
  </div>
</div>

Decreasing for loops in Python impossible?

Late to the party, but for anyone tasked with creating their own or wants to see how this would work, here's the function with an added bonus of rearranging the start-stop values based on the desired increment:

def RANGE(start, stop=None, increment=1):
    if stop is None:
        stop = start
        start = 1

    value_list = sorted([start, stop])

    if increment == 0:
        print('Error! Please enter nonzero increment value!')
    else:
        value_list = sorted([start, stop])
        if increment < 0:
            start = value_list[1]
            stop = value_list[0]
            while start >= stop:
                worker = start
                start += increment
                yield worker
        else:
            start = value_list[0]
            stop = value_list[1]
            while start < stop:
                worker = start
                start += increment
                yield worker

Negative increment:

for i in RANGE(1, 10, -1):
    print(i)

Or, with start-stop reversed:

for i in RANGE(10, 1, -1):
    print(i)

Output:

Regular increment:

for i in RANGE(1, 10):
    print(i)

Output:

Zero increment:

for i in RANGE(1, 10, 0):
    print(i)

Output:

'Error! Please enter nonzero increment value!'

css with background image without repeating the image

This is all you need:

background-repeat: no-repeat;

How to refresh or show immediately in datagridview after inserting?

You can set the datagridview DataSource to null and rebind it again.

private void button1_Click(object sender, EventArgs e)
{
    myAccesscon.ConnectionString = connectionString;

    dataGridView.DataSource = null;
    dataGridView.Update();
    dataGridView.Refresh();
    OleDbCommand cmd = new OleDbCommand(sql, myAccesscon);
    myAccesscon.Open();
    cmd.CommandType = CommandType.Text;
    OleDbDataAdapter da = new OleDbDataAdapter(cmd);
    DataTable bookings = new DataTable();
    da.Fill(bookings);
    dataGridView.DataSource = bookings;
    myAccesscon.Close();
}

Shrinking navigation bar when scrolling down (bootstrap3)

If you are using AngularJS, and you are using Angular Bootstrap : https://angular-ui.github.io/bootstrap/

You can do this so nice like this :

HTML:

<nav id="header-navbar" class="navbar navbar-default" ng-class="{'navbar-fixed-top':scrollDown}" role="navigation" scroll-nav>
    <div class="container-fluid top-header">
        <!--- Rest of code --->
    </div>
</nav>

CSS: (Note here I use padding as bigger nav to shrink without padding you can modify as you want)

nav.navbar {
  -webkit-transition: all 0.4s ease;
  transition: all 0.4s ease;

  background-color: white;
  margin-bottom: 0;
  padding: 25px;
}

.navbar-fixed-top {
  padding: 0;
}

And then add your directive

Directive: (Note you may need to change this.pageYOffset >= 50 from 50 to more or less to fulfill your needs)

angular.module('app')
.directive('scrollNav', function ($window) {
  return function(scope, element, attrs) {
    angular.element($window).bind("scroll", function() {
      if (this.pageYOffset >= 50) {
        scope.scrollDown = true;
      } else {
        scope.scrollDown = false;
      }
      scope.$apply();
    });
  };
});

This will do the job nicely, animated and cool way.

The application may be doing too much work on its main thread

Try to use the following strategies in order to improve your app performance:

Use multi-threading programming if possible. The performance benefits are huge, even if your smart phone has one core (threads can run in different cores, if the processor has two or more). It's useful to make your app logic separated from the UI. Use Java threads, AsyncTask or IntentService. Check this.
Read and follow the misc performance tips of Android development website. Check here.

How Can I Set the Default Value of a Timestamp Column to the Current Timestamp with Laravel Migrations?

If your're looking to set the current datetime for a dateTime column (like i was when I googled), use this way

$table->dateTime('signed_when')->useCurrent();

npx command not found

try :

sudo su

then

npm i npx 
or 
npi i -g npx

check your npx version by

npx -v

Is there a Python Library that contains a list of all the ascii characters?

Here it is:

[chr(i) for i in xrange(127)]

Singleton: How should it be used

Singletons give you the ability to combine two bad traits in one class. That's wrong in pretty much every way.

A singleton gives you:

Global access to an object, and
A guarantee that no more than one object of this type can ever be created

Number one is straightforward. Globals are generally bad. We should never make objects globally accessible unless we really need it.

Number two may sound like it makes sense, but let's think about it. When was the last time you **accidentally* created a new object instead of referencing an existing one? Since this is tagged C++, let's use an example from that language. Do you often accidentally write

std::ostream os;
os << "hello world\n";

When you intended to write

std::cout << "hello world\n";

Of course not. We don't need protection against this error, because that kind of error just doesn't happen. If it does, the correct response is to go home and sleep for 12-20 hours and hope you feel better.

If only one object is needed, simply create one instance. If one object should be globally accessible, make it a global. But that doesn't mean it should be impossible to create other instances of it.

The "only one instance is possible" constraint doesn't really protect us against likely bugs. But it does make our code very hard to refactor and maintain. Because quite often we find out later that we did need more than one instance. We do have more than one database, we do have more than one configuration object, we do want several loggers. Our unit tests may want to be able to create and recreate these objects every test, to take a common example.

So a singleton should be used if and only if, we need both the traits it offers: If we need global access (which is rare, because globals are generally discouraged) and we need to prevent anyone from ever creating more than one instance of a class (which sounds to me like a design issue). The only reason I can see for this is if creating two instances would corrupt our application state - probably because the class contains a number of static members or similar silliness. In which case the obvious answer is to fix that class. It shouldn't depend on being the only instance.

If you need global access to an object, make it a global, like std::cout. But don't constrain the number of instances that can be created.

If you absolutely, positively need to constrain the number of instances of a class to just one, and there is no way that creating a second instance can ever be handled safely, then enforce that. But don't make it globally accessible as well.

If you do need both traits, then 1) make it a singleton, and 2) let me know what you need that for, because I'm having a hard time imagining such a case.

Can I avoid the native fullscreen video player with HTML5 on iPhone or android?

According to this page https://developer.apple.com/library/archive/documentation/AppleApplications/Reference/SafariHTMLRef/Articles/Attributes.html it is only available if (Enabled only in a UIWebView with the allowsInlineMediaPlayback property set to YES.) I understand in Mobile Safari this is YES on iPad and NO on iPhone and iPod Touch.

How to use RecyclerView inside NestedScrollView?

There are a lot of good answers. The key is that you must set nestedScrollingEnabled to false. As mentioned above you can do it in java code:

mRecyclerView.setNestedScrollingEnabled(false);

But also you have an opportunity to set the same property in xml code (android:nestedScrollingEnabled="false"):

 <android.support.v7.widget.RecyclerView
 android:id="@+id/recyclerview"
 android:nestedScrollingEnabled="false"
 android:layout_width="match_parent"
 android:layout_height="match_parent" />

Get Request and Session Parameters and Attributes from JSF pages

Are you sure you can't get access to request / session scope variables from a JSF page?

This is what I'm doing in our login page, using Spring Security:

<h:outputText
    rendered="#{param.loginFailed == 1 and SPRING_SECURITY_LAST_EXCEPTION != null}">
    <span class="msg-error">#{SPRING_SECURITY_LAST_EXCEPTION.message}</span>
</h:outputText>

getting exception "IllegalStateException: Can not perform this action after onSaveInstanceState"

Read http://chris-alexander.co.uk/on-engineering/dev/android-fragments-within-fragments/

article. fragment.isResumed() checking helps me in onDestroyView w/o using onSaveInstanceState method.

Android Activity without ActionBar

open Manifest and add attribute theme = "@style/Theme.AppCompat.Light.NoActionBar" to activity you want it without actionbar :

<application
    ...
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity"
        android:theme="@style/Theme.AppCompat.Light.NoActionBar">
        ...
    </activity>
</application>

How to execute a * .PY file from a * .IPYNB file on the Jupyter notebook?

Maybe not very elegant, but it does the job:

exec(open("script.py").read())

Any way to break if statement in PHP?

To completely stop the rest of the script from running you can just do

exit; //In place of break. The rest of the code will not execute

Multiple Inheritance in C#

Multiple inheritance is one of those things that generally causes more problems than it solves. In C++ it fits the pattern of giving you enough rope to hang yourself, but Java and C# have chosen to go the safer route of not giving you the option. The biggest problem is what to do if you inherit multiple classes that have a method with the same signature that the inheritee doesn't implement. Which class's method should it choose? Or should that not compile? There is generally another way to implement most things that doesn't rely on multiple inheritance.

html select scroll bar

Horizontal scrollbars in a HTML Select are not natively supported. However, here's a way to create the appearance of a horizontal scrollbar:

1. First create a css class

<style type="text/css">
 .scrollable{
   overflow: auto;
   width: 70px; /* adjust this width depending to amount of text to display */
   height: 80px; /* adjust height depending on number of options to display */
   border: 1px silver solid;
 }
 .scrollable select{
   border: none;
 }
</style>

2. Wrap the SELECT inside a DIV - also, explicitly set the size to the number of options.

<div class="scrollable">
<select size="6" multiple="multiple">
    <option value="1" selected>option 1 The Long Option</option>
    <option value="2">option 2</option>
    <option value="3">option 3</option>
    <option value="4">option 4</option>
    <option value="5">option 5 Another Longer than the Long Option ;)</option>
    <option value="6">option 6</option>
</select>
</div>

How Can I Bypass the X-Frame-Options: SAMEORIGIN HTTP Header?

As for second question - you can use Fiddler filters to set response X-Frame-Options header manually to something like ALLOW-FROM *. But, of course, this trick will work only for you - other users still won't be able to see iframe content(if they not do the same).

High CPU Utilization in java application - why?

You did not assign the "linux" to the question but you mentioned "Linux top". And thus this might be helpful:

Use the small Linux tool threadcpu to identify the most cpu using threads. It calls jstack to get the thread name. And with "sort -n" in pipe you get the list of threads ordered by cpu usage.

More details can be found here: http://www.tuxad.com/blog/archives/2018/10/01/threadcpu_-_show_cpu_usage_of_threads/index.html

And if you still need more details then create a thread dump or run strace on the thread.

How to get featured image of a product in woocommerce

This should do the trick:

<?php
    $product_meta = get_post_meta($post_id);
    echo wp_get_attachment_image( $product_meta['_thumbnail_id'][0], 'full' );
?>

You can change the parameters according to your needs.

Using an instance of an object as a key in hashmap, and then access it with exactly new object?

Equal height rows in a flex container

No, you can't achieve that without setting a fixed height (or using a script).

Here are 2 answers of mine, showing how to use a script to achieve something like that:

How to import/include a CSS file using PHP code and not HTML code?

If you want to import a CSS file like that, just give the file itself a .php extension and import it anyway. It will work just fine :)

How to disable Google asking permission to regularly check installed apps on my phone?

In Nexus 5, Go to Settings -> Google -> Security and uncheck "Scan device for Security threats" and "Improve harmful app detection".

How to run a function when the page is loaded?

Take a look at the domReady script that allows setting up of multiple functions to execute when the DOM has loaded. It's basically what the Dom ready does in many popular JavaScript libraries, but is lightweight and can be taken and added at the start of your external script file.

Example usage

// add reference to domReady script or place 
// contents of script before here

function codeAddress() {

}

domReady(codeAddress);

How to pass a querystring or route parameter to AWS Lambda from Amazon API Gateway

Now you should be able to use the new proxy integration type for Lambda to automatically get the full request in standard shape, rather than configure mappings.

see: http://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-set-up-simple-proxy.html#api-gateway-set-up-lambda-proxy-integration-on-proxy-resource

How do I increase the capacity of the Eclipse output console?

Under Window > Preferences, go to the Run/Debug > Console section, then you should see an option "Limit console output." You can unchecked this or change the number in the "Console buffer size (characters)" text box below. Do Unchecked.

This is for the Eclipse like Galileo, Kepler, Juno, Luna, Mars and Helios.

How to define Singleton in TypeScript

After implementing a classic pattern like

class Singleton {
  private instance: Singleton;
  
  private constructor() {}

  public getInstance() {
    if (!this.instance) { 
      this.instance = new Singleton();
    }
    return this.instance;
  }
}

I realized it's pretty useless in case you want some other class to be a singleton too. It's not extendable. You have to write that singleton stuff for every class you want to be a singleton.

Decorators for the rescue.

@singleton
class MyClassThatIsSingletonToo {}

You can write decorator by yourself or take some from npm. I found this proxy-based implementation from @keenondrums/singleton package neat enough.

How to calculate a Mod b in Casio fx-991ES calculator

It all falls back to the definition of modulus: It is the remainder, for example, 7 mod 3 = 1. This because 7 = 3(2) + 1, in which 1 is the remainder.

To do this process on a simple calculator do the following: Take the dividend (7) and divide by the divisor (3), note the answer and discard all the decimals -> example 7/3 = 2.3333333, only worry about the 2. Now multiply this number by the divisor (3) and subtract the resulting number from the original dividend.

so 2*3 = 6, and 7 - 6 = 1, thus 1 is 7mod3

How to send parameters from a notification-click to an activity?

In your notification implementation, use a code like this:

NotificationCompat.Builder nBuilder = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID);
...
Intent intent = new Intent(this, ExampleActivity.class);
intent.putExtra("EXTRA_KEY", "value");

PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
nBuilder.setContentIntent(pendingIntent);
...

To Get Intent extra values in the ExampleActivity, use the following code:

...
Intent intent = getIntent();
if(intent!=null) {
    String extraKey = intent.getStringExtra("EXTRA_KEY");
}
...

VERY IMPORTANT NOTE: the Intent::putExtra() method is an Overloaded one. To get the extra key, you need to use Intent::get[Type]Extra() method.

Note: NOTIFICATION_ID and NOTIFICATION_CHANNEL_ID are an constants declared in ExampleActivity

How do I hide certain files from the sidebar in Visual Studio Code?

You can configure patterns to hide files and folders from the explorer and searches.

Open VS User Settings (Main menu: File > Preferences > Settings). This will open the setting screen.
Search for files:exclude in the search at the top.
Configure the User Setting with new glob patterns as needed. In this case add this pattern node_modules/ then click OK. The pattern syntax is powerful. You can find pattern matching details under the Search Across Files topic.

When you are done it should look something like this:

If you want to directly edit the settings file: For example to hide a top level node_modules folder in your workspace:

"files.exclude": {
    "node_modules/": true
}

To hide all files that start with ._ such as ._.DS_Store files found on OSX:

"files.exclude": {
    "**/._*": true
}

You also have the ability to change Workspace Settings (Main menu: File > Preferences > Workspace Settings). Workspace settings will create a .vscode/settings.json file in your current workspace and will only be applied to that workspace. User Settings will be applied globally to any instance of VS Code you open, but they won't override Workspace Settings if present. Read more on customizing User and Workspace Settings.

How to make HTML Text unselectable

No one here posted an answer with all of the correct CSS variations, so here it is:

-webkit-touch-callout: none;
-webkit-user-select: none;
-khtml-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;

Using If else in SQL Select statement

sql server 2012

  with
  student as 
(select sid,year from (
values (101,5),(102,5),(103,4),(104,3),(105,2),(106,1),(107,4)
) as student(sid,year)
)
select iif(year=5,sid,year) as myCol,* from student


 myCol  sid year
101 101 5
102 102 5
4   103 4
3   104 3
2   105 2
1   106 1
4   107 4

Returning multiple values from a C++ function

In C++11 you can:

#include <tuple>

std::tuple<int, int> divide(int dividend, int divisor) {
    return  std::make_tuple(dividend / divisor, dividend % divisor);
}

#include <iostream>

int main() {
    using namespace std;

    int quotient, remainder;

    tie(quotient, remainder) = divide(14, 3);

    cout << quotient << ',' << remainder << endl;
}

In C++17:

#include <tuple>

std::tuple<int, int> divide(int dividend, int divisor) {
    return  {dividend / divisor, dividend % divisor};
}

#include <iostream>

int main() {
    using namespace std;

    auto [quotient, remainder] = divide(14, 3);

    cout << quotient << ',' << remainder << endl;
}

or with structs:

auto divide(int dividend, int divisor) {
    struct result {int quotient; int remainder;};
    return result {dividend / divisor, dividend % divisor};
}

#include <iostream>

int main() {
    using namespace std;

    auto result = divide(14, 3);

    cout << result.quotient << ',' << result.remainder << endl;

    // or

    auto [quotient, remainder] = divide(14, 3);

    cout << quotient << ',' << remainder << endl;
}

SQL Select between dates

Change your data to that formats to use sqlite datetime formats.

YYYY-MM-DD
YYYY-MM-DD HH:MM
YYYY-MM-DD HH:MM:SS
YYYY-MM-DD HH:MM:SS.SSS
YYYY-MM-DDTHH:MM
YYYY-MM-DDTHH:MM:SS
YYYY-MM-DDTHH:MM:SS.SSS
HH:MM
HH:MM:SS
HH:MM:SS.SSS
now
DDDDDDDDDD

SELECT * FROM test WHERE date BETWEEN '2011-01-11' AND '2011-08-11'

Visual c++ can't open include file 'iostream'

Some things that you should check:

Check the include folder in your version of VS (in "C:\Program Files\Microsoft Visual Studio xx.x\VC\include" check for the file which you are including, iostream, make sure it's there).
Check your projects Include Directories in <Project Name> > Properties > Configuration Properties > VC++ Directories > Include Directories - (it should look like this: $(VCInstallDir)include;$(VCInstallDir)atlmfc\include;$(WindowsSdkDir)include;$(FrameworkSDKDir)\include;)
Make sure that you selected the correct project for this code (File > New > Project > Visual C++ > Win32 Console Application)
Make sure that you don't have <iostream.h> anywhere in your code files, VS doesn't support that (in the same project, check your other code files, .cpp and .h files for <iostream.h> and remove it).
Make sure that you don't have more than one main() function in your project code files (in the same project, check your other code files, .cpp and .h files for the main() function and remove it or replace it with another name).

Some things you could try building with:

Exclude using namespace std; from your main() function and put it after the include directive.
Use std::cout without using namespace std;.

turn typescript object into json string

If you're using fs-extra, you can skip the JSON.stringify part with the writeJson function:

const fsExtra = require('fs-extra');

fsExtra.writeJson('./package.json', {name: 'fs-extra'})
.then(() => {
  console.log('success!')
})
.catch(err => {
  console.error(err)
})

How to redirect output of systemd service to a file

I would suggest adding stdout and stderr file in systemd service file itself.

Referring : https://www.freedesktop.org/software/systemd/man/systemd.exec.html#StandardOutput=

As you have configured it should not like:

StandardOutput=/home/user/log1.log
StandardError=/home/user/log2.log

It should be:

StandardOutput=file:/home/user/log1.log
StandardError=file:/home/user/log2.log

This works when you don't want to restart the service again and again.

This will create a new file and does not append to the existing file.

Use Instead:

StandardOutput=append:/home/user/log1.log
StandardError=append:/home/user/log2.log

NOTE: Make sure you create the directory already. I guess it does not support to create a directory.

What parameters should I use in a Google Maps URL to go to a lat-lon?

New Version queries have a different format

To reach a lat long by url use (e.g.)

https://www.google.com/maps/search/-15.924,-5.719

Create an enum with string values

This works for me:

class MyClass {
    static MyEnum: { Value1; Value2; Value3; }
    = {
        Value1: "Value1",
        Value2: "Value2",
        Value3: "Value3"
    };
}

module MyModule {
    export var MyEnum: { Value1; Value2; Value3; }
    = {
        Value1: "Value1",
        Value2: "Value2",
        Value3: "Value3"
    };
}

Update: Shortly after posting this I discovered another way, but forgot to post an update (however, someone already did mentioned it above):

enum MyEnum {
    value1 = <any>"value1 ", 
    value2 = <any>"value2 ", 
    value3 = <any>"value3 " 
}

How to Select a substring in Oracle SQL up to a specific character?

Remember this if all your Strings in the column do not have an underscore (...or else if null value will be the output):

SELECT COALESCE
(SUBSTR("STRING_COLUMN" , 0, INSTR("STRING_COLUMN", '_')-1), 
"STRING_COLUMN") 
AS OUTPUT FROM DUAL

Copy entire directory contents to another directory?

The following is an example of using JDK7.

public class CopyFileVisitor extends SimpleFileVisitor<Path> {
    private final Path targetPath;
    private Path sourcePath = null;
    public CopyFileVisitor(Path targetPath) {
        this.targetPath = targetPath;
    }

    @Override
    public FileVisitResult preVisitDirectory(final Path dir,
    final BasicFileAttributes attrs) throws IOException {
        if (sourcePath == null) {
            sourcePath = dir;
        } else {
        Files.createDirectories(targetPath.resolve(sourcePath
                    .relativize(dir)));
        }
        return FileVisitResult.CONTINUE;
    }

    @Override
    public FileVisitResult visitFile(final Path file,
    final BasicFileAttributes attrs) throws IOException {
    Files.copy(file,
        targetPath.resolve(sourcePath.relativize(file)));
    return FileVisitResult.CONTINUE;
    }
}

To use the visitor do the following

Files.walkFileTree(sourcePath, new CopyFileVisitor(targetPath));

If you'd rather just inline everything (not too efficient if you use it often, but good for quickies)

    final Path targetPath = // target
    final Path sourcePath = // source
    Files.walkFileTree(sourcePath, new SimpleFileVisitor<Path>() {
        @Override
        public FileVisitResult preVisitDirectory(final Path dir,
                final BasicFileAttributes attrs) throws IOException {
            Files.createDirectories(targetPath.resolve(sourcePath
                    .relativize(dir)));
            return FileVisitResult.CONTINUE;
        }

        @Override
        public FileVisitResult visitFile(final Path file,
                final BasicFileAttributes attrs) throws IOException {
            Files.copy(file,
                    targetPath.resolve(sourcePath.relativize(file)));
            return FileVisitResult.CONTINUE;
        }
    });

How to access the elements of a function's return array?

Your function is:

function data(){

$a = "abc";
$b = "def";
$c = "ghi";

return array($a, $b, $c);
}

It returns an array where position 0 is $a, position 1 is $b and position 2 is $c. You can therefore access $a by doing just this:

data()[0]

If you do $myvar = data()[0] and print $myvar, you will get "abc", which was the value assigned to $a inside the function.

Error in finding last used cell in Excel with VBA

NOTE: I intend to make this a "one stop post" where you can use the Correct way to find the last row. This will also cover the best practices to follow when finding the last row. And hence I will keep on updating it whenever I come across a new scenario/information.

Unreliable ways of finding the last row

Some of the most common ways of finding last row which are highly unreliable and hence should never be used.

UsedRange
xlDown
CountA

UsedRange should NEVER be used to find the last cell which has data. It is highly unreliable. Try this experiment.

Type something in cell A5. Now when you calculate the last row with any of the methods given below, it will give you 5. Now color the cell A10 red. If you now use the any of the below code, you will still get 5. If you use Usedrange.Rows.Count what do you get? It won't be 5.

Here is a scenario to show how UsedRange works.

enter image description here

xlDown is equally unreliable.

Consider this code

lastrow = Range("A1").End(xlDown).Row

What would happen if there was only one cell (A1) which had data? You will end up reaching the last row in the worksheet! It's like selecting cell A1 and then pressing End key and then pressing Down Arrow key. This will also give you unreliable results if there are blank cells in a range.

CountA is also unreliable because it will give you incorrect result if there are blank cells in between.

And hence one should avoid the use of UsedRange, xlDown and CountA to find the last cell.

Find Last Row in a Column

To find the last Row in Col E use this

With Sheets("Sheet1")
    LastRow = .Range("E" & .Rows.Count).End(xlUp).Row
End With

If you notice that we have a . before Rows.Count. We often chose to ignore that. See THIS question on the possible error that you may get. I always advise using . before Rows.Count and Columns.Count. That question is a classic scenario where the code will fail because the Rows.Count returns 65536 for Excel 2003 and earlier and 1048576 for Excel 2007 and later. Similarly Columns.Count returns 256 and 16384, respectively.

The above fact that Excel 2007+ has 1048576 rows also emphasizes on the fact that we should always declare the variable which will hold the row value as Long instead of Integer else you will get an Overflow error.

Note that this approach will skip any hidden rows. Looking back at my screenshot above for column A, if row 8 were hidden, this approach would return 5 instead of 8.

Find Last Row in a Sheet

To find the Effective last row in the sheet, use this. Notice the use of Application.WorksheetFunction.CountA(.Cells). This is required because if there are no cells with data in the worksheet then .Find will give you Run Time Error 91: Object Variable or With block variable not set

With Sheets("Sheet1")
    If Application.WorksheetFunction.CountA(.Cells) <> 0 Then
        lastrow = .Cells.Find(What:="*", _
                      After:=.Range("A1"), _
                      Lookat:=xlPart, _
                      LookIn:=xlFormulas, _
                      SearchOrder:=xlByRows, _
                      SearchDirection:=xlPrevious, _
                      MatchCase:=False).Row
    Else
        lastrow = 1
    End If
End With

Find Last Row in a Table (ListObject)

The same principles apply, for example to get the last row in the third column of a table:

Sub FindLastRowInExcelTableColAandB()
Dim lastRow As Long
Dim ws As Worksheet, tbl as ListObject
Set ws = Sheets("Sheet1")  'Modify as needed
'Assuming the name of the table is "Table1", modify as needed
Set tbl = ws.ListObjects("Table1")

With tbl.ListColumns(3).Range
    lastrow = .Find(What:="*", _
                After:=.Cells(1), _
                Lookat:=xlPart, _
                LookIn:=xlFormulas, _
                SearchOrder:=xlByRows, _
                SearchDirection:=xlPrevious, _
                MatchCase:=False).Row
End With

End Sub

What's the difference between JavaScript and JScript?

According to this article:

JavaScript is a scripting language developed by Netscape Communications designed for developing client and server Internet applications. Netscape Navigator is designed to interpret JavaScript embedded into Web pages. JavaScript is independent of Sun Microsystem's Java language.
Microsoft JScript is an open implementation of Netscape's JavaScript. JScript is a high-performance scripting language designed to create active online content for the World Wide Web. JScript allows developers to link and automate a wide variety of objects in Web pages, including ActiveX controls and Java programs. Microsoft Internet Explorer is designed to interpret JScript embedded into Web pages.

PHP returning JSON to JQUERY AJAX CALL

You can return json in PHP this way:

header('Content-Type: application/json');
echo json_encode(array('foo' => 'bar'));
exit;

Set div height equal to screen size

use

 $(document).height()

property and set to the div from script and set

  overflow=auto

for scrolling

How to crop an image in OpenCV using Python

Below is the way to crop an image.

image_path: The path to the image to edit

coords: A tuple of x/y coordinates (x1, y1, x2, y2)[open the image in mspaint and check the "ruler" in view tab to see the coordinates]

saved_location: Path to save the cropped image

from PIL import Image
    def crop(image_path, coords, saved_location:
        image_obj = Image.open("Path of the image to be cropped")
            cropped_image = image_obj.crop(coords)
            cropped_image.save(saved_location)
            cropped_image.show()


if __name__ == '__main__':
    image = "image.jpg"
    crop(image, (100, 210, 710,380 ), 'cropped.jpg')

How to install SignTool.exe for Windows 10

If you're using VS Express 2015, just go to your control panel --> programs and features --> select vs 2015 --> click change, then in the VS Express installer select 'Modify' --> select Publishing tools, and finish. Once setup completes the changes you will be able to create your installer.

best way to get the key of a key/value javascript object

If you want to get all keys, ECMAScript 5 introduced Object.keys. This is only supported by newer browsers but the MDC documentation provides an alternative implementation (which also uses for...in btw):

if(!Object.keys) Object.keys = function(o){
     if (o !== Object(o))
          throw new TypeError('Object.keys called on non-object');
     var ret=[],p;
     for(p in o) if(Object.prototype.hasOwnProperty.call(o,p)) ret.push(p);
     return ret;
}

Of course if you want both, key and value, then for...in is the only reasonable solution.

What dependency is missing for org.springframework.web.bind.annotation.RequestMapping?

the problem's actually caused by dependency. I spent whole the day to solve this prblm. Firstly, right click on project > Maven > add dependency

In "EnterGroupId, ArtifactId, or sha1...." box, type "org.springframework".

Then, from droped down list, expand "spring-web" list > Choose the newest version of jar file > Click OK.
Done!!!

INSERT statement conflicted with the FOREIGN KEY constraint - SQL Server

It means exactly what it says. You're trying to insert a value into a column that has a FK constraint on it that doesn't match any values in the lookup table.

How to sort a file, based on its numerical values for a field?

Use sort -n or sort --numeric-sort.

How to add image background to btn-default twitter-bootstrap button?

Have you tried using a icon font like http://fortawesome.github.io/Font-Awesome/

Bootstrap comes with their own library, but it doesn't have as many icons as Font Awesome.

http://getbootstrap.com/components/#glyphicons

rebase in progress. Cannot commit. How to proceed or stop (abort)?

I setup my git to autorebase on a git checkout

# in my ~/.gitconfig file
[branch]
    autosetupmerge = always
    autosetuprebase = always

Otherwise, it automatically merges when you switch between branches, which I think is the worst possible choice as the default.

However, this has a side effect, when I switch to a branch and then git cherry-pick <commit-id> I end up in this weird state every single time it has a conflict.

I actually have to abort the rebase, but first I fix the conflict, git add /path/to/file the file (another very strange way to resolve the conflict in this case?!), then do a git commit -i /path/to/file. Now I can abort the rebase:

git checkout <other-branch>
git cherry-pick <commit-id>
...edit-conflict(s)...
git add path/to/file
git commit -i path/to/file
git rebase --abort
git commit .
git push --force origin <other-branch>

The second git commit . seems to come from the abort. I'll fix my answer if I find out that I should abort the rebase sooner.

The --force on the push is required if you skip other commits and both branches are not smooth (both are missing commits from the other).

Difference between Amazon EC2 and AWS Elastic Beanstalk

First off, EC2 and Elastic Compute Cloud are the same thing.

Next, AWS encompasses the range of Web Services that includes EC2 and Elastic Beanstalk. It also includes many others such as S3, RDS, DynamoDB, and all the others.

EC2

EC2 is Amazon's service that allows you to create a server (AWS calls these instances) in the AWS cloud. You pay by the hour and only what you use. You can do whatever you want with this instance as well as launch n number of instances.

Elastic Beanstalk

Elastic Beanstalk is one layer of abstraction away from the EC2 layer. Elastic Beanstalk will setup an "environment" for you that can contain a number of EC2 instances, an optional database, as well as a few other AWS components such as a Elastic Load Balancer, Auto-Scaling Group, Security Group. Then Elastic Beanstalk will manage these items for you whenever you want to update your software running in AWS. Elastic Beanstalk doesn't add any cost on top of these resources that it creates for you. If you have 10 hours of EC2 usage, then all you pay is 10 compute hours.

Running Wordpress

For running Wordpress, it is whatever you are most comfortable with. You could run it straight on a single EC2 instance, you could use a solution from the AWS Marketplace, or you could use Elastic Beanstalk.

What to pick?

In the case that you want to reduce system operations and just focus on the website, then Elastic Beanstalk would be the best choice for that. Elastic Beanstalk supports a PHP stack (as well as others). You can keep your site in version control and easily deploy to your environment whenever you make changes. It will also setup an Autoscaling group which can spawn up more EC2 instances if traffic is growing.

Here's the first result off of Google when searching for "elastic beanstalk wordpress": https://www.otreva.com/blog/deploying-wordpress-amazon-web-services-aws-ec2-rds-via-elasticbeanstalk/

Proper way to return JSON using node or Express

Older version of Express use app.use(express.json()) or bodyParser.json() read more about bodyParser middleware

On latest version of express we could simply use res.json()

const express = require('express'),
    port = process.env.port || 3000,
    app = express()

app.get('/', (req, res) => res.json({key: "value"}))

app.listen(port, () => console.log(`Server start at ${port}`))

How to define optional methods in Swift protocol?

Put the @optional in front of methods or properties.

Is it possible to register a http+domain-based URL Scheme for iPhone apps, like YouTube and Maps?

window.location = appurl;// fb://method/call..
!window.document.webkitHidden && setTimeout(function () {
    setTimeout(function () {
    window.location = weburl; // http://itunes.apple.com/..
    }, 100);
}, 600);

document.webkitHidden is to detect if your app is already invoked and current safari tab to going to the background, this code is from www.baidu.com

How to export database schema in Oracle to a dump file

It depends on which version of Oracle? Older versions require exp (export), newer versions use expdp (data pump); exp was deprecated but still works most of the time.

Before starting, note that Data Pump exports to the server-side Oracle "directory", which is an Oracle symbolic location mapped in the database to a physical location. There may be a default directory (DATA_PUMP_DIR), check by querying DBA_DIRECTORIES:

  SQL> select * from dba_directories;

... and if not, create one

  SQL> create directory DATA_PUMP_DIR as '/oracle/dumps';
  SQL> grant all on directory DATA_PUMP_DIR to myuser;    -- DBAs dont need this grant

Assuming you can connect as the SYSTEM user, or another DBA, you can export any schema like so, to the default directory:

 $ expdp system/manager schemas=user1 dumpfile=user1.dpdmp

Or specifying a specific directory, add directory=<directory name>:

 C:\> expdp system/manager schemas=user1 dumpfile=user1.dpdmp directory=DUMPDIR

With older export utility, you can export to your working directory, and even on a client machine that is remote from the server, using:

 $ exp system/manager owner=user1 file=user1.dmp

Make sure the export is done in the correct charset. If you haven't setup your environment, the Oracle client charset may not match the DB charset, and Oracle will do charset conversion, which may not be what you want. You'll see a warning, if so, then you'll want to repeat the export after setting NLS_LANG environment variable so the client charset matches the database charset. This will cause Oracle to skip charset conversion.

Example for American UTF8 (UNIX):

 $ export NLS_LANG=AMERICAN_AMERICA.AL32UTF8

Windows uses SET, example using Japanese UTF8:

 C:\> set NLS_LANG=Japanese_Japan.AL32UTF8

More info on Data Pump here: http://docs.oracle.com/cd/B28359_01/server.111/b28319/dp_export.htm#g1022624

Cannot implicitly convert type 'string' to 'System.Threading.Tasks.Task<string>'

The listed return type of the method is Task<string>. You're trying to return a string. They are not the same, nor is there an implicit conversion from string to Task<string>, hence the error.

You're likely confusing this with an async method in which the return value is automatically wrapped in a Task by the compiler. Currently that method is not an async method. You almost certainly meant to do this:

private async Task<string> methodAsync() 
{
    await Task.Delay(10000);
    return "Hello";
}

There are two key changes. First, the method is marked as async, which means the return type is wrapped in a Task, making the method compile. Next, we don't want to do a blocking wait. As a general rule, when using the await model always avoid blocking waits when you can. Task.Delay is a task that will be completed after the specified number of milliseconds. By await-ing that task we are effectively performing a non-blocking wait for that time (in actuality the remainder of the method is a continuation of that task).

If you prefer a 4.0 way of doing it, without using await , you can do this:

private Task<string> methodAsync() 
{
    return Task.Delay(10000)
        .ContinueWith(t => "Hello");
}

The first version will compile down to something that is more or less like this, but it will have some extra boilerplate code in their for supporting error handling and other functionality of await we aren't leveraging here.

If your Thread.Sleep(10000) is really meant to just be a placeholder for some long running method, as opposed to just a way of waiting for a while, then you'll need to ensure that the work is done in another thread, instead of the current context. The easiest way of doing that is through Task.Run:

private Task<string> methodAsync() 
{
    return Task.Run(()=>
        {
            SomeLongRunningMethod();
            return "Hello";
        });
}

Or more likely:

private Task<string> methodAsync() 
{
    return Task.Run(()=>
        {
            return SomeLongRunningMethodThatReturnsAString();
        });
}

Android: long click on a button -> perform actions

Change return false; to return true; in longClickListener

You long click the button, if it returns true then it does the work. If it returns false then it does it's work and also calls the short click and then the onClick also works.

What is InputStream & Output Stream? Why and when do we use them?

A stream is a continuous flow of liquid, air, or gas.

Java stream is a flow of data from a source into a destination. The source or destination can be a disk, memory, socket, or other programs. The data can be bytes, characters, or objects. The same applies for C# or C++ streams. A good metaphor for Java streams is water flowing from a tap into a bathtub and later into a drainage.

The data represents the static part of the stream; the read and write methods the dynamic part of the stream.

InputStream represents a flow of data from the source, the OutputStream represents a flow of data into the destination. Finally, InputStream and OutputStream are abstractions over low-level access to data, such as C file pointers.

Shuffle an array with python, randomize array item order with python

You can sort your array with random key

sorted(array, key = lambda x: random.random())

key only be read once so comparing item during sort still efficient.

but look like random.shuffle(array) will be faster since it written in C

How do I validate a date in this format (yyyy-mm-dd) using jquery?

You can use this one it's for YYYY-MM-DD. It checks if it's a valid date and that the value is not NULL. It returns TRUE if everythings check out to be correct or FALSE if anything is invalid. It doesn't get easier then this!

function validateDate(date) {
    var matches = /^(\d{4})[-\/](\d{2})[-\/](\d{2})$/.exec(date);
    if (matches == null) return false;
    var d = matches[3];
    var m = matches[2] - 1;
    var y = matches[1] ;
    var composedDate = new Date(y, m, d);
    return composedDate.getDate() == d &&
            composedDate.getMonth() == m &&
            composedDate.getFullYear() == y;
}

Be aware that months need to be subtracted like this: var m = matches[2] - 1; else the new Date() instance won't be properly made.

How to horizontally center an element

You can do it by using Flexbox which is a good technique these days.

For using Flexbox you should give display: flex; and align-items: center; to your parent or #outer div element. The code should be like this:

_x000D_

#outer {_x000D_
  display: flex;_x000D_
  align-items: center;_x000D_
}

_x000D_

<div id="outer">_x000D_
  <div id="inner">Foo foo</div>_x000D_
</div>

_x000D_

This should center your child or #inner div horizontally. But you can't actually see any changes. Because our #outer div has no height or in other words, its height is set to auto, so it has the same height as all of its child elements. So after a little of visual styling, the result code should be like this:

_x000D_

#outer {_x000D_
  height: 500px;_x000D_
  display: flex;_x000D_
  align-items: center;_x000D_
  background-color: blue;_x000D_
}_x000D_
_x000D_
#inner {_x000D_
  height: 100px;_x000D_
  background: yellow;_x000D_
}

_x000D_

<div id="outer">_x000D_
  <div id="inner">Foo foo</div>_x000D_
</div>

_x000D_

You can see #inner div is now centered. Flexbox is the new method of positioning elements in horizontal or vertical stacks with CSS and it's got 96% of global browsers compatibility. So you are free to use it and if you want to find out more about Flexbox visit CSS-Tricks article. That is the best place to learn using Flexbox in my opinion.

CSS background image alt attribute

You can achieve this by putting the alt tag in the div were your image will appear.

Example:

<div id="yourImage" alt="nameOfImage"></div>

What are the minimum margins most printers can handle?

As a general rule of thumb, I use 1 cm margins when producing pdfs. I work in the geospatial industry and produce pdf maps that reference a specific geographic scale. Therefore, I do not have the option to 'fit document to printable area,' because this would make the reference scale inaccurate. You must also realize that when you fit to printable area, you are fitting your already existing margins inside the printer margins, so you end up with double margins. Make your margins the right size and your documents will print perfectly. Many modern printers can print with margins less than 3 mm, so 1 cm as a general rule should be sufficient. However, if it is a high profile job, get the specs of the printer you will be printing with and ensure that your margins are adequate. All you need is the brand and model number and you can find spec sheets through a google search.

Adding open/closed icon to Twitter Bootstrap collapsibles (accordions)

The most readable CSS-only solution would probably be to use the aria-expanded attribute. Remember that you'll need to add aria-expanded="false" to all collapse-elements as this is not set on load (only on first click).

The HTML:

<h2 data-toggle="collapse" href="#collapseId" aria-expanded="false">
    <span class="glyphicon glyphicon-chevron-right"></span>
    <span class="glyphicon glyphicon-chevron-down"></span> Title
</h2>

The CSS:

h2[aria-expanded="false"] span.glyphicon-chevron-down,
h2[aria-expanded="true"] span.glyphicon-chevron-right
{
    display: none;
}

h2[aria-expanded="true"] span.glyphicon-chevron-down,
h2[aria-expanded="false"] span.glyphicon-chevron-right
{
    display: inline;
}

Works with Bootstrap 3.x.

How to change the current URL in javascript?

What you're doing is appending a "1" (the string) to your URL. If you want page 1.html link to page 2.html you need to take the 1 out of the string, add one to it, then reassemble the string.

Why not do something like this:

var url = 'http://mywebsite.com/1.html';
var pageNum = parseInt( url.split("/").pop(),10 );
var nextPage = 'http://mywebsite.com/'+(pageNum+1)+'.html';

nextPage will contain the url http://mywebsite.com/2.html in this case. Should be easy to put in a function if needed.

Where/how can I download (and install) the Microsoft.Jet.OLEDB.4.0 for Windows 8, 64 bit?

Make sure to target x86 on your project in Visual Studio. This should fix your trouble.

Get first element in PHP stdObject

Update PHP 7.4

Curly brace access syntax is deprecated since PHP 7.4

Update 2019

Moving on to the best practices of OOPS, @MrTrick's answer must be marked as correct, although my answer provides a hacked solution its not the best method.

Simply iterate its using {}

Example:

$videos{0}->id

This way your object is not destroyed and you can easily iterate through object.

For PHP 5.6 and below use this

$videos{0}['id']

Both array() and the stdClass objects can be accessed using the current() key() next() prev() reset() end() functions.

So, if your object looks like

object(stdClass)#19 (3) {
  [0]=>
  object(stdClass)#20 (22) {
    ["id"]=>
    string(1) "123"
  etc...

Then you can just do;

$id = reset($obj)->id; //Gets the 'id' attr of the first entry in the object

If you need the key for some reason, you can do;

reset($obj); //Ensure that we're at the first element
$key = key($obj);

Hope that works for you. :-) No errors, even in super-strict mode, on PHP 5.4

2022 Update:
After PHP 7.4, using current(), end(), etc functions on objects is deprecated.

In newer versions of PHP, use the ArrayIterator class:

$objIterator = new ArrayIterator($obj);

$id = $objIterator->current()->id; // Gets the 'id' attr of the first entry in the object

$key = $objIterator->key(); // and gets the key

How can I tell when HttpClient has timed out?

Basically, you need to catch the OperationCanceledException and check the state of the cancellation token that was passed to SendAsync (or GetAsync, or whatever HttpClient method you're using):

if it was canceled (IsCancellationRequested is true), it means the request really was canceled
if not, it means the request timed out

Of course, this isn't very convenient... it would be better to receive a TimeoutException in case of timeout. I propose a solution here based on a custom HTTP message handler: Better timeout handling with HttpClient

Where do I find the line number in the Xcode editor?

Sure, Xcode->Preferences and turn on Show line numbers.

How to create a stopwatch using JavaScript?

Two native solutions

performance.now --> Call to ... took 6.414999981643632 milliseconds.
console.time --> Call to ... took 5.815 milliseconds

The difference between both is precision.

For usage and explanation read on.

Performance.now (For microsecond precision use)

_x000D_

    var t0 = performance.now();
    doSomething();
    var t1 = performance.now();

    console.log("Call to doSomething took " + (t1 - t0) + " milliseconds.");
            
    function doSomething(){    
       for(i=0;i<1000000;i++){var x = i*i;}
    }

_x000D_

performance.now

Unlike other timing data available to JavaScript (for example Date.now), the timestamps returned by Performance.now() are not limited to one-millisecond resolution. Instead, they represent times as floating-point numbers with up to microsecond precision.

Also unlike Date.now(), the values returned by Performance.now() always increase at a constant rate, independent of the system clock (which might be adjusted manually or skewed by software like NTP). Otherwise, performance.timing.navigationStart + performance.now() will be approximately equal to Date.now().

console.time

Example: (timeEnd wrapped in setTimeout for simulation)

_x000D_

console.time('Search page');
  doSomething();
console.timeEnd('Search page');
 

 function doSomething(){    
       for(i=0;i<1000000;i++){var x = i*i;}
 }

_x000D_

You can change the Timer-Name for different operations.

hide/show a image in jquery

If you're trying to hide upload img and show bandwidth img on bandwidth click and viceversa this would work

<script>

    function show_img(id)
    {
        if(id=='bandwidth')
        {
           $("#upload").hide();
           $("#bandwith").show();
        }
        else if(id=='upload')
        {
            $("#upload").show();
            $("#bandwith").hide();
        }
    return false;
     } 
    </script>
    <a href="#" onclick="javascript:show_img('bandwidth');">Bandwidth</a>
    <a href="#" onclick="javascript:show_img('upload');">Upload</a>
    <p align="center"> 
      <img src="/media/img/close.png" style="visibility: hidden;" id="bandwidth"/>
      <img src="/media/img/close.png" style="visibility: hidden;" id="upload"/>
    </p>

Fixed digits after decimal with f-strings

Include the type specifier in your format expression:

>>> a = 10.1234
>>> f'{a:.2f}'
'10.12'

Where is my .vimrc file?

Useful Information can be obtained using the `find` command

find / -iname "*vimrc*" -type f 2>/dev/null

There are many answers already, but it can sometimes be useful to simply run a "find" for anything containing the name "vimrc".

The reason is that this will show you what files you actualy have available on the system currently, rather than what you might put on your system. (The information for which you would obtain from :version as explained in other answers.)

Example result on my system

On my system this produces

/usr/share/vim/vim82/vimrc_example.vim
/usr/share/vim/vim82/gvimrc_example.vim
/etc/vim/gvimrc
/etc/vim/vimrc
/etc/vim/vimrc.tiny

Which is quite useful because it tells us that there are 2 example files installed in the share directorys for both gvim and vim, and that there are also some system-wide config files below /etc/.

On my system, I also have a file at ~/.vimrc but this does not appear in this list because it is a link to another file, stored under ~/Linux-Config. But you won't have this directory, it's specific to machines I use on my own network.

Detailed Explanation of `find` syntax used

Explanation:

find starting at the root directory / (find works recursively)
anything containing the case insensitive regex *vimrc* which means any name with vimrc (case insensitive) in it somewhere, can be preceeded or followed by anything or nothing (*)
type = files (not directory/symlink etc)
throw all errors to /dev/null otherwise the output is spammed with unreadable errors from /proc

android TextView: setting the background color dynamically doesn't work

Use et.setBackgroundResource(R.color.white);

Getting visitors country from their IP

Check out php-ip-2-country from code.google. The database they provide is updated daily, so it is not necessary to connect to an outside server for the check if you host your own SQL server. So using the code you would only have to type:

<?php
$ip = $_SERVER['REMOTE_ADDR'];

if(!empty($ip)){
        require('./phpip2country.class.php');

        /**
         * Newest data (SQL) avaliable on project website
         * @link http://code.google.com/p/php-ip-2-country/
         */
        $dbConfigArray = array(
                'host' => 'localhost', //example host name
                'port' => 3306, //3306 -default mysql port number
                'dbName' => 'ip_to_country', //example db name
                'dbUserName' => 'ip_to_country', //example user name
                'dbUserPassword' => 'QrDB9Y8CKMdLDH8Q', //example user password
                'tableName' => 'ip_to_country', //example table name
        );

        $phpIp2Country = new phpIp2Country($ip,$dbConfigArray);
        $country = $phpIp2Country->getInfo(IP_COUNTRY_NAME);
        echo $country;
?>

Example Code (from the resource)

<?
require('phpip2country.class.php');

$dbConfigArray = array(
        'host' => 'localhost', //example host name
        'port' => 3306, //3306 -default mysql port number
        'dbName' => 'ip_to_country', //example db name
        'dbUserName' => 'ip_to_country', //example user name
        'dbUserPassword' => 'QrDB9Y8CKMdLDH8Q', //example user password
        'tableName' => 'ip_to_country', //example table name
);

$phpIp2Country = new phpIp2Country('213.180.138.148',$dbConfigArray);

print_r($phpIp2Country->getInfo(IP_INFO));
?>

Output

Array
(
    [IP_FROM] => 3585376256
    [IP_TO] => 3585384447
    [REGISTRY] => RIPE
    [ASSIGNED] => 948758400
    [CTRY] => PL
    [CNTRY] => POL
    [COUNTRY] => POLAND
    [IP_STR] => 213.180.138.148
    [IP_VALUE] => 3585378964
    [IP_FROM_STR] => 127.255.255.255
    [IP_TO_STR] => 127.255.255.255
)

Converting ArrayList to HashMap

Using a supposed name property as the map key:

for (Product p: productList) { s.put(p.getName(), p); }

How to disable button in React.js

Using refs is not best practice because it reads the DOM directly, it's better to use React's state instead. Also, your button doesn't change because the component is not re-rendered and stays in its initial state.

You can use setState together with an onChange event listener to render the component again every time the input field changes:

// Input field listens to change, updates React's state and re-renders the component.
<input onChange={e => this.setState({ value: e.target.value })} value={this.state.value} />

// Button is disabled when input state is empty.
<button disabled={!this.state.value} />

Here's a working example:

_x000D_

class AddItem extends React.Component {_x000D_
  constructor() {_x000D_
    super();_x000D_
    this.state = { value: '' };_x000D_
    this.onChange = this.onChange.bind(this);_x000D_
    this.add = this.add.bind(this);_x000D_
  }_x000D_
_x000D_
  add() {_x000D_
    this.props.onButtonClick(this.state.value);_x000D_
    this.setState({ value: '' });_x000D_
  }_x000D_
_x000D_
  onChange(e) {_x000D_
    this.setState({ value: e.target.value });_x000D_
  }_x000D_
_x000D_
  render() {_x000D_
    return (_x000D_
      <div className="add-item">_x000D_
        <input_x000D_
          type="text"_x000D_
          className="add-item__input"_x000D_
          value={this.state.value}_x000D_
          onChange={this.onChange}_x000D_
          placeholder={this.props.placeholder}_x000D_
        />_x000D_
        <button_x000D_
          disabled={!this.state.value}_x000D_
          className="add-item__button"_x000D_
          onClick={this.add}_x000D_
        >_x000D_
          Add_x000D_
        </button>_x000D_
      </div>_x000D_
    );_x000D_
  }_x000D_
}_x000D_
_x000D_
ReactDOM.render(_x000D_
  <AddItem placeholder="Value" onButtonClick={v => console.log(v)} />,_x000D_
  document.getElementById('View')_x000D_
);

_x000D_

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>_x000D_
<div id='View'></div>

_x000D_

How to create User/Database in script for Docker Postgres

You can use this commands:

docker exec -it yournamecontainer psql -U postgres -c "CREATE DATABASE mydatabase ENCODING 'LATIN1' TEMPLATE template0 LC_COLLATE 'C' LC_CTYPE 'C';"

docker exec -it yournamecontainer psql -U postgres -c "GRANT ALL PRIVILEGES ON DATABASE postgres TO postgres;"

Full width layout with twitter bootstrap

In Bootstrap 3, columns are specified using percentages. (In Bootstrap 2, this was only the case if a column/span was within a .row-fluid element, but that's no longer necessary and that class no longer exists.) If you use a .container, then @Michael is absolutely right that you'll be stuck with a fixed-width layout. However, you should be in good shape if you just avoid using a .container element.

<body>
  <div class="row">
    <div class="col-lg-4">...</div>
    <div class="col-lg-8">...</div>
  </div>
</body>

The margin for the body is already 0, so you should be able to get up right to the edge. (Columns still have a 15px padding on both sides, so you may have to account for that in your design, but this shouldn't stop you, and you can always customize this when you download Bootstrap.)

What's an appropriate HTTP status code to return by a REST API service for a validation failure?

What exactly do you mean by "validation failure"? What are you validating? Are you referring to something like a syntax error (e.g. malformed XML)?

If that's the case, I'd say 400 Bad Request is probably the right thing, but without knowing what it is you're "validating", it's impossible to say.

Iterator over HashMap in Java

Several problems here:

You probably don't use the correct iterator class. As others said, use import java.util.Iterator
If you want to use Map.Entry entry = (Map.Entry) iter.next(); then you need to use hm.entrySet().iterator(), not hm.keySet().iterator(). Either you iterate on the keys, or on the entries.

How do I pretty-print existing JSON data with Java?

In one line:

String niceFormattedJson = JsonWriter.formatJson(jsonString)

System.out.println(JsonWriter.formatJson(jsonString.toString()));

The json-io libray (https://github.com/jdereg/json-io) is a small (75K) library with no other dependencies than the JDK.

In addition to pretty-printing JSON, you can serialize Java objects (entire Java object graphs with cycles) to JSON, as well as read them in.

How to check for a JSON response using RSpec?

I found a customer matcher here: https://raw.github.com/gist/917903/92d7101f643e07896659f84609c117c4c279dfad/have_content_type.rb

Put it in spec/support/matchers/have_content_type.rb and make sure to load stuff from support with something like this in you spec/spec_helper.rb

Dir[Rails.root.join('spec/support/**/*.rb')].each {|f| require f}

Here is the code itself, just in case it disappeared from the given link.

RSpec::Matchers.define :have_content_type do |content_type|
  CONTENT_HEADER_MATCHER = /^(.*?)(?:; charset=(.*))?$/

  chain :with_charset do |charset|
    @charset = charset
  end

  match do |response|
    _, content, charset = *content_type_header.match(CONTENT_HEADER_MATCHER).to_a

    if @charset
      @charset == charset && content == content_type
    else
      content == content_type
    end
  end

  failure_message_for_should do |response|
    if @charset
      "Content type #{content_type_header.inspect} should match #{content_type.inspect} with charset #{@charset}"
    else
      "Content type #{content_type_header.inspect} should match #{content_type.inspect}"
    end
  end

  failure_message_for_should_not do |model|
    if @charset
      "Content type #{content_type_header.inspect} should not match #{content_type.inspect} with charset #{@charset}"
    else
      "Content type #{content_type_header.inspect} should not match #{content_type.inspect}"
    end
  end

  def content_type_header
    response.headers['Content-Type']
  end
end

How to get GET (query string) variables in Express.js on Node.js?

//get query&params in express

//etc. example.com/user/000000?sex=female

app.get('/user/:id', function(req, res) {

  const query = req.query;// query = {sex:"female"}

  const params = req.params; //params = {id:"000000"}

})

How do I add comments to package.json for npm install?

Here's my take on comments within package.json / bower.json:

I have file package.json.js that contains a script that exports the actual package.json. Running the script overwrites the old package.json and tells me what changes it made, perfect to help you keep track of automatic changes npm made. That way I can even programmatically define what packages I want to use.

The latest Grunt task is here: https://gist.github.com/MarZab/72fa6b85bc9e71de5991

Scrolling a flexbox with overflowing content

.list-wrap {
  width: 355px;
  height: 100%;
  position: relative;

  .list {
    position: absolute;
    top: 0;
    bottom: 0;
    overflow-y: auto;
    width: 100%;
  }
}

Catch error if iframe src fails to load . Error :-"Refused to display 'http://www.google.co.in/' in a frame.."

The onload will always be trigger, i slove this problem use try catch block.It will throw an exception when you try to get the contentDocument.

iframe.onload = function(){
   var that = $(this)[0];
   try{
        that.contentDocument;
   }
   catch(err){
        //TODO 
   }
}

How do I turn off the mysql password validation?

For references and the future, one should read the doc here https://dev.mysql.com/doc/mysql-secure-deployment-guide/5.7/en/secure-deployment-password-validation.html

Then you should edit your mysqld.cnf file, for instance :

vim /etc/mysql/mysql.conf.d/mysqld.cnf

Then, add in the [mysqld] part, the following :

plugin-load-add=validate_password.so
validate_password_policy=LOW

Basically, if you edit your default, it will looks like :

[mysqld]
#
# * Basic Settings
#
user            = mysql
pid-file        = /var/run/mysqld/mysqld.pid
socket          = /var/run/mysqld/mysqld.sock
port            = 3306
basedir         = /usr
datadir         = /var/lib/mysql
tmpdir          = /tmp
lc-messages-dir = /usr/share/mysql
skip-external-locking
plugin-load-add=validate_password.so
validate_password_policy=LOW

Then, you can restart:

systemctl restart mysql

If you forget the plugin-load-add=validate_password.so part, you will it an error at restart.

Enjoy !

When is a C++ destructor called?

1) If the object is created via a pointer and that pointer is later deleted or given a new address to point to, does the object that it was pointing to call its destructor (assuming nothing else is pointing to it)?

It depends on the type of pointers. For example, smart pointers often delete their objects when they are deleted. Ordinary pointers do not. The same is true when a pointer is made to point to a different object. Some smart pointers will destroy the old object, or will destroy it if it has no more references. Ordinary pointers have no such smarts. They just hold an address and allow you to perform operations on the objects they point to by specifically doing so.

2) Following up on question 1, what defines when an object goes out of scope (not regarding to when an object leaves a given {block}). So, in other words, when is a destructor called on an object in a linked list?

That's up to the implementation of the linked list. Typical collections destroy all their contained objects when they are destroyed.

So, a linked list of pointers would typically destroy the pointers but not the objects they point to. (Which may be correct. They may be references by other pointers.) A linked list specifically designed to contain pointers, however, might delete the objects on its own destruction.

A linked list of smart pointers could automatically delete the objects when the pointers are deleted, or do so if they had no more references. It's all up to you to pick the pieces that do what you want.

3) Would you ever want to call a destructor manually?

Sure. One example would be if you want to replace an object with another object of the same type but don't want to free memory just to allocate it again. You can destroy the old object in place and construct a new one in place. (However, generally this is a bad idea.)

// pointer is destroyed because it goes out of scope,
// but not the object it pointed to. memory leak
if (1) {
 Foo *myfoo = new Foo("foo");
}


// pointer is destroyed because it goes out of scope,
// object it points to is deleted. no memory leak
if(1) {
 Foo *myfoo = new Foo("foo");
 delete myfoo;
}

// no memory leak, object goes out of scope
if(1) {
 Foo myfoo("foo");
}

Ripple effect on Android Lollipop CardView

I wasn't happy with AppCompat, so I wrote my own CardView and backported ripples. Here it's running on Galaxy S with Gingerbread, so it's definitely possible.

Demo of Ripple on Galaxy S

For more details check the source code.

insert password into database in md5 format?

if you want to use md5 encryptioon you can do it in your php script

$pass = $_GET['pass'];

$newPass = md5($pass)

and then insert it into the database that way, however MD5 is a one way encryption method and is near on impossible to decrypt without difficulty

Creating a UITableView Programmatically

#import "ViewController.h"

@interface ViewController ()

{

    NSMutableArray *name;

}

@end


- (void)viewDidLoad 

{

    [super viewDidLoad];
    name=[[NSMutableArray alloc]init];
    [name addObject:@"ronak"];
    [name addObject:@"vibha"];
    [name addObject:@"shivani"];
    [name addObject:@"nidhi"];
    [name addObject:@"firdosh"];
    [name addObject:@"himani"];

    _tableview_outlet.delegate = self;
    _tableview_outlet.dataSource = self;

}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

{

return [name count];

}


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

{

    static NSString *simpleTableIdentifier = @"cell";

    UITableViewCell *cell = [tableView       dequeueReusableCellWithIdentifier:simpleTableIdentifier];

    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
    }

    cell.textLabel.text = [name objectAtIndex:indexPath.row];
    return cell;
}

How do I create a view controller file after creating a new view controller?

Correct, when you drag a view controller object onto your storyboard in order to create a new scene, it doesn't automatically make the new class for you, too.

Having added a new view controller scene to your storyboard, you then have to:

Create a UIViewController subclass. For example, go to your target's folder in the project navigator panel on the left and then control-click and choose "New File...". Choose a "Cocoa Touch Class":

And then select a unique name for the new view controller subclass:
Specify this new subclass as the base class for the scene you just added to the storyboard.
Now hook up any IBOutlet and IBAction references for this new scene with the new view controller subclass.

How to read single Excel cell value

It is better to use .Value2() instead of .Value(). This is faster and gives the exact value in the cell. For certain type of data, truncation can be observed when .Value() is used.

How can I convert tabs to spaces in every file of a directory?

Collecting the best comments from Gene's answer, the best solution by far, is by using sponge from moreutils.

sudo apt-get install moreutils
# The complete one-liner:
find ./ -iname '*.java' -type f -exec bash -c 'expand -t 4 "$0" | sponge "$0"' {} \;

Explanation:

./ is recursively searching from current directory
-iname is a case insensitive match (for both *.java and *.JAVA likes)
type -f finds only regular files (no directories, binaries or symlinks)
-exec bash -c execute following commands in a subshell for each file name, {}
expand -t 4 expands all TABs to 4 spaces
sponge soak up standard input (from expand) and write to a file (the same one)*.

NOTE: * A simple file redirection (> "$0") won't work here because it would overwrite the file too soon.

Advantage: All original file permissions are retained and no intermediate tmp files are used.

Couldn't connect to server 127.0.0.1:27017

If you are using OS X systems, there is no service commands. So you won't be able to execure sudo service mongod start.

Check this answer https://unix.stackexchange.com/a/155746 for more help!

jQuery creating objects

May be you want this (oop in javascript)

function box(color)
{
    this.color=color;
}

var box1=new box('red');    
var box2=new box('white');

DEMO.

For more information.

How to delete/remove nodes on Firebase

As others have noted the call to .remove() is asynchronous. We should all be aware nothing happens 'instantly', even if it is at the speed of light.

What you mean by 'instantly' is that the next line of code should be able to execute after the call to .remove(). With asynchronous operations the next line may be when the data has been removed, it may not - it is totally down to chance and the amount of time that has elapsed.

.remove() takes one parameter a callback function to help deal with this situation to perform operations after we know that the operation has been completed (with or without an error). .push() takes two params, a value and a callback just like .remove().

Here is your example code with modifications:

ref = new Firebase("myfirebase.com")

ref.push({key:val}, function(error){
  //do stuff after push completed
});

// deletes all data pushed so far
ref.remove(function(error){
  //do stuff after removal
});

Catch checked change event of a checkbox

Use the :checked selector to determine the checkbox's state:

$('input[type=checkbox]').click(function() {
    if($(this).is(':checked')) {
        ...
    } else {
        ...
    }
});

Delete the last two characters of the String

You may also try the following code with exception handling. Here you have a method removeLast(String s, int n) (it is actually an modified version of masud.m's answer). You have to provide the String s and how many char you want to remove from the last to this removeLast(String s, int n) function. If the number of chars have to remove from the last is greater than the given String length then it throws a StringIndexOutOfBoundException with a custom message -

public String removeLast(String s, int n) throws StringIndexOutOfBoundsException{

        int strLength = s.length();

        if(n>strLength){
            throw new StringIndexOutOfBoundsException("Number of character to remove from end is greater than the length of the string");
        }

        else if(null!=s && !s.isEmpty()){

            s = s.substring(0, s.length()-n);
        }

        return s;

    }

Good tool to visualise database schema?

Try PHPMyAdmin which has some really nice visualisation and editing feature. I am pretty sure you can even export to exel from it.

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