Programs & Examples On #Null string

std::string to char*

char* result = strcpy((char*)malloc(str.length()+1), str.c_str());

How to detect reliably Mac OS X, iOS, Linux, Windows in C preprocessor?

There are predefined macros that are used by most compilers, you can find the list here. GCC compiler predefined macros can be found here. Here is an example for gcc:

#if defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__)
   //define something for Windows (32-bit and 64-bit, this part is common)
   #ifdef _WIN64
      //define something for Windows (64-bit only)
   #else
      //define something for Windows (32-bit only)
   #endif
#elif __APPLE__
    #include <TargetConditionals.h>
    #if TARGET_IPHONE_SIMULATOR
         // iOS Simulator
    #elif TARGET_OS_IPHONE
        // iOS device
    #elif TARGET_OS_MAC
        // Other kinds of Mac OS
    #else
    #   error "Unknown Apple platform"
    #endif
#elif __linux__
    // linux
#elif __unix__ // all unices not caught above
    // Unix
#elif defined(_POSIX_VERSION)
    // POSIX
#else
#   error "Unknown compiler"
#endif

The defined macros depend on the compiler that you are going to use.

The _WIN64 #ifdef can be nested into the _WIN32 #ifdef because _WIN32 is even defined when targeting the Windows x64 version. This prevents code duplication if some header includes are common to both (also WIN32 without underscore allows IDE to highlight the right partition of code).

HTTP post XML data in C#

In General:

An example of an easy way to post XML data and get the response (as a string) would be the following function:

public string postXMLData(string destinationUrl, string requestXml)
{
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(destinationUrl);
    byte[] bytes;
    bytes = System.Text.Encoding.ASCII.GetBytes(requestXml);
    request.ContentType = "text/xml; encoding='utf-8'";
    request.ContentLength = bytes.Length;
    request.Method = "POST";
    Stream requestStream = request.GetRequestStream();
    requestStream.Write(bytes, 0, bytes.Length);
    requestStream.Close();
    HttpWebResponse response;
    response = (HttpWebResponse)request.GetResponse();
    if (response.StatusCode == HttpStatusCode.OK)
    {
        Stream responseStream = response.GetResponseStream();
        string responseStr = new StreamReader(responseStream).ReadToEnd();
        return responseStr;
    }
    return null;
}

In your specific situation:

Instead of:

request.ContentType = "application/x-www-form-urlencoded";

use:

request.ContentType = "text/xml; encoding='utf-8'";

Also, remove:

string postData = "XMLData=" + Sendingxml;

And replace:

byte[] byteArray = Encoding.UTF8.GetBytes(postData);

with:

byte[] byteArray = Encoding.UTF8.GetBytes(Sendingxml.ToString());

How do I generate sourcemaps when using babel and webpack?

Maybe someone else has this problem at one point. If you use the UglifyJsPlugin in webpack 2 you need to explicitly specify the sourceMap flag. For example:

new webpack.optimize.UglifyJsPlugin({ sourceMap: true })

Is it a good idea to index datetime field in mysql?

MySQL recommends using indexes for a variety of reasons including elimination of rows between conditions: http://dev.mysql.com/doc/refman/5.0/en/mysql-indexes.html

This makes your datetime column an excellent candidate for an index if you are going to be using it in conditions frequently in queries. If your only condition is BETWEEN NOW() AND DATE_ADD(NOW(), INTERVAL 30 DAY) and you have no other index in the condition, MySQL will have to do a full table scan on every query. I'm not sure how many rows are generated in 30 days, but as long as it's less than about 1/3 of the total rows it will be more efficient to use an index on the column.

Your question about creating an efficient database is very broad. I'd say to just make sure that it's normalized and all appropriate columns are indexed (i.e. ones used in joins and where clauses).

Simplest way to restart service on a remote computer

look at sysinternals for a variety of tools to help you achieve that goal. psService for example would restart a service on a remote machine.

How do I create dynamic properties in C#?

Create a Hashtable called "Properties" and add your properties to it.

Open Url in default web browser

Try this:

import React, { useCallback } from "react";
import { Linking } from "react-native";
OpenWEB = () => {
  Linking.openURL(url);
};

const App = () => {
  return <View onPress={() => OpenWeb}>OPEN YOUR WEB</View>;
};

Hope this will solve your problem.

Remove specific rows from a data frame

 X <- data.frame(Variable1=c(11,14,12,15),Variable2=c(2,3,1,4))
> X
  Variable1 Variable2
1        11         2
2        14         3
3        12         1
4        15         4
> X[X$Variable1!=11 & X$Variable1!=12, ]
  Variable1 Variable2
2        14         3
4        15         4
> X[ ! X$Variable1 %in% c(11,12), ]
  Variable1 Variable2
2        14         3
4        15         4

You can functionalize this however you like.

How to modify existing, unpushed commit messages?

I realised that I had pushed a commit with a typo in it. In order to undo, I did the following:

git commit --amend -m "T-1000, advanced prototype"
git push --force

Warning: force pushing your changes will overwrite the remote branch with your local one. Make sure that you aren't going to be overwriting anything that you want to keep. Also be cautious about force pushing an amended (rewritten) commit if anyone else shares the branch with you, because they'll need to rewrite their own history if they have the old copy of the commit that you've just rewritten.

Script to kill all connections to a database (More than RESTRICTED_USER ROLLBACK)

You can get the script that SSMS provides by doing the following:

  1. Right-click on a database in SSMS and choose delete
  2. In the dialog, check the checkbox for "Close existing connections."
  3. Click the Script button at the top of the dialog.

The script will look something like this:

USE [master]
GO
ALTER DATABASE [YourDatabaseName] SET  SINGLE_USER WITH ROLLBACK IMMEDIATE
GO
USE [master]
GO
DROP DATABASE [YourDatabaseName]
GO

Resize image in the wiki of GitHub using Markdown

Almost 5 years after only the direct HTML formatting works for images on GitHub and other markdown options still prevent images from loading when specifying some custom sizes even with the wrong dimensions. I prefer to specify the desired width and get the height calculated automatically, for example,

_x000D_
_x000D_
<img src="https://github.com/your_image.png" alt="Your image title" width="250"/>
_x000D_
_x000D_
_x000D_

Can someone explain Microsoft Unity?

Unity is a library like many others that allows you to get an instance of a requested type without having to create it yourself. So given.

public interface ICalculator
{
    void Add(int a, int b);
}

public class Calculator : ICalculator
{
    public void Add(int a, int b)
    {
        return a + b;
    }
}

You would use a library like Unity to register Calculator to be returned when the type ICalculator is requested aka IoC (Inversion of Control) (this example is theoretical, not technically correct).

IoCLlibrary.Register<ICalculator>.Return<Calculator>();

So now when you want an instance of an ICalculator you just...

Calculator calc = IoCLibrary.Resolve<ICalculator>();

IoC libraries can usually be configured to either hold a singleton or create a new instance every time you resolve a type.

Now let's say you have a class that relies on an ICalculator to be present you could have..

public class BankingSystem
{
    public BankingSystem(ICalculator calc)
    {
        _calc = calc;
    }

    private ICalculator _calc;
}

And you can setup the library to inject a object into the constructor when it's created.

So DI or Dependency Injection means to inject any object another might require.

JavaScript: function returning an object

In JavaScript, most functions are both callable and instantiable: they have both a [[Call]] and [[Construct]] internal methods.

As callable objects, you can use parentheses to call them, optionally passing some arguments. As a result of the call, the function can return a value.

var player = makeGamePlayer("John Smith", 15, 3);

The code above calls function makeGamePlayer and stores the returned value in the variable player. In this case, you may want to define the function like this:

function makeGamePlayer(name, totalScore, gamesPlayed) {
  // Define desired object
  var obj = {
    name:  name,
    totalScore: totalScore,
    gamesPlayed: gamesPlayed
  };
  // Return it
  return obj;
}

Additionally, when you call a function you are also passing an additional argument under the hood, which determines the value of this inside the function. In the case above, since makeGamePlayer is not called as a method, the this value will be the global object in sloppy mode, or undefined in strict mode.

As constructors, you can use the new operator to instantiate them. This operator uses the [[Construct]] internal method (only available in constructors), which does something like this:

  1. Creates a new object which inherits from the .prototype of the constructor
  2. Calls the constructor passing this object as the this value
  3. It returns the value returned by the constructor if it's an object, or the object created at step 1 otherwise.
var player = new GamePlayer("John Smith", 15, 3);

The code above creates an instance of GamePlayer and stores the returned value in the variable player. In this case, you may want to define the function like this:

function GamePlayer(name,totalScore,gamesPlayed) {
  // `this` is the instance which is currently being created
  this.name =  name;
  this.totalScore = totalScore;
  this.gamesPlayed = gamesPlayed;
  // No need to return, but you can use `return this;` if you want
}

By convention, constructor names begin with an uppercase letter.

The advantage of using constructors is that the instances inherit from GamePlayer.prototype. Then, you can define properties there and make them available in all instances

How do I run a Python script from C#?

Execute Python script from C

Create a C# project and write the following code.

using System;
using System.Diagnostics;
using System.IO;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            run_cmd();
        }

        private void run_cmd()
        {

            string fileName = @"C:\sample_script.py";

            Process p = new Process();
            p.StartInfo = new ProcessStartInfo(@"C:\Python27\python.exe", fileName)
            {
                RedirectStandardOutput = true,
                UseShellExecute = false,
                CreateNoWindow = true
            };
            p.Start();

            string output = p.StandardOutput.ReadToEnd();
            p.WaitForExit();

            Console.WriteLine(output);

            Console.ReadLine();

        }
    }
}

Python sample_script

print "Python C# Test"

You will see the 'Python C# Test' in the console of C#.

How to correctly save instance state of Fragments in back stack?

I just want to give the solution that I came up with that handles all cases presented in this post that I derived from Vasek and devconsole. This solution also handles the special case when the phone is rotated more than once while fragments aren't visible.

Here is were I store the bundle for later use since onCreate and onSaveInstanceState are the only calls that are made when the fragment isn't visible

MyObject myObject;
private Bundle savedState = null;
private boolean createdStateInDestroyView;
private static final String SAVED_BUNDLE_TAG = "saved_bundle";

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    if (savedInstanceState != null) {
        savedState = savedInstanceState.getBundle(SAVED_BUNDLE_TAG);
    }
}

Since destroyView isn't called in the special rotation situation we can be certain that if it creates the state we should use it.

@Override
public void onDestroyView() {
    super.onDestroyView();
    savedState = saveState();
    createdStateInDestroyView = true;
    myObject = null;
}

This part would be the same.

private Bundle saveState() { 
    Bundle state = new Bundle();
    state.putSerializable(SAVED_BUNDLE_TAG, myObject);
    return state;
}

Now here is the tricky part. In my onActivityCreated method I instantiate the "myObject" variable but the rotation happens onActivity and onCreateView don't get called. Therefor, myObject will be null in this situation when the orientation rotates more than once. I get around this by reusing the same bundle that was saved in onCreate as the out going bundle.

    @Override
public void onSaveInstanceState(Bundle outState) {

    if (myObject == null) {
        outState.putBundle(SAVED_BUNDLE_TAG, savedState);
    } else {
        outState.putBundle(SAVED_BUNDLE_TAG, createdStateInDestroyView ? savedState : saveState());
    }
    createdStateInDestroyView = false;
    super.onSaveInstanceState(outState);
}

Now wherever you want to restore the state just use the savedState bundle

  @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    ...
    if(savedState != null) {
        myObject = (MyObject) savedState.getSerializable(SAVED_BUNDLE_TAG);
    }
    ...
}

How to submit a form on enter when the textarea has focus?

<form id="myform">
    <input type="textbox" id="field"/>
    <input type="button" value="submit">
</form>

<script>
    $(function () {
        $("#field").keyup(function (event) {
            if (event.which === 13) {
                document.myform.submit();
            }
        }
    });
</script>

How to show the text on a ImageButton?

ImageButton can't have text (or, at least, android:text isn't listed in its attributes).

The Trick is:

It looks like you need to use Button (and look at drawableTop or setCompoundDrawablesWithIntrinsicBounds(int,int,int,int)).

Call external javascript functions from java code

Use ScriptEngine.eval(java.io.Reader) to read the script

ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("JavaScript");
// read script file
engine.eval(Files.newBufferedReader(Paths.get("C:/Scripts/Jsfunctions.js"), StandardCharsets.UTF_8));

Invocable inv = (Invocable) engine;
// call function from script file
inv.invokeFunction("yourFunction", "param");

Git pull command from different user

Your question is a little unclear, but if what you're doing is trying to get your friend's latest changes, then typically what your friend needs to do is to push those changes up to a remote repo (like one hosted on GitHub), and then you fetch or pull those changes from the remote:

  1. Your friend pushes his changes to GitHub:

    git push origin <branch>
    
  2. Clone the remote repository if you haven't already:

    git clone https://[email protected]/abc/theproject.git
    
  3. Fetch or pull your friend's changes (unnecessary if you just cloned in step #2 above):

    git fetch origin
    git merge origin/<branch>
    

    Note that git pull is the same as doing the two steps above:

    git pull origin <branch>
    

See Also

What is the difference between persist() and merge() in JPA and Hibernate?

The most important difference is this:

  • In case of persist method, if the entity that is to be managed in the persistence context, already exists in persistence context, the new one is ignored. (NOTHING happened)

  • But in case of merge method, the entity that is already managed in persistence context will be replaced by the new entity (updated) and a copy of this updated entity will return back. (from now on any changes should be made on this returned entity if you want to reflect your changes in persistence context)

Calling ASP.NET MVC Action Methods from JavaScript

You can set up your element with

value="@model.productId"

and

onclick= addToWishList(this.value);

Implement Validation for WPF TextBoxes

When I needed to do this, I followed Microsoft's example using Binding.ValidationRules and it worked first time.

See their article, How to: Implement Binding Validation: https://docs.microsoft.com/en-us/dotnet/desktop/wpf/data/how-to-implement-binding-validation?view=netframeworkdesktop-4.8

Get Bitmap attached to ImageView

Bitmap bitmap = ((BitmapDrawable)image.getDrawable()).getBitmap();

Mongoose: CastError: Cast to ObjectId failed for value "[object Object]" at path "_id"

If you are having this issue and you are performing a populate somewhere along the lines, see this Mongoose issue.

Update to Mongoose 4.0 and the issue has been fixed.

Simulating a click in jQuery/JavaScript on a link

Easy! Just use jQuery's click function:

$("#theElement").click();

"int cannot be dereferenced" in Java

As your methods an int datatype, you should use "==" instead of equals()

try replacing this if (id.equals(list[pos].getItemNumber()))

with

if (id.equals==list[pos].getItemNumber())

it will fix the error .

JTable won't show column headers

As said in previous answers the 'normal' way is to add it to a JScrollPane, but sometimes you don't want it to scroll (don't ask me when:)). Then you can add the TableHeader yourself. Like this:

JPanel tablePanel = new JPanel(new BorderLayout());
JTable table = new JTable();
tablePanel.add(table, BorderLayout.CENTER);
tablePanel.add(table.getTableHeader(), BorderLayout.NORTH);

How to see tomcat is running or not

for localhost,the defaut port is 8080,you can test the link http://localhost:8080 in you browser.if you can see tomcat home page,your tomcat is running

C/C++ maximum stack size of program

In Visual Studio the default stack size is 1 MB i think, so with a recursion depth of 10,000 each stack frame can be at most ~100 bytes which should be sufficient for a DFS algorithm.

Most compilers including Visual Studio let you specify the stack size. On some (all?) linux flavours the stack size isn't part of the executable but an environment variable in the OS. You can then check the stack size with ulimit -s and set it to a new value with for example ulimit -s 16384.

Here's a link with default stack sizes for gcc.

DFS without recursion:

std::stack<Node> dfs;
dfs.push(start);
do {
    Node top = dfs.top();
    if (top is what we are looking for) {
       break;
    }
    dfs.pop();
    for (outgoing nodes from top) {
        dfs.push(outgoing node);
    }
} while (!dfs.empty())

How to disable input conditionally in vue.js

Not difficult, check this.

<button @click="disabled = !disabled">Toggle Enable</button>
<input type="text" id="name" class="form-control" name="name"  v-model="form.name" :disabled="disabled">

jsfiddle

Check if a Windows service exists and delete in PowerShell

  • For PowerShell versions prior to v6, you can do this:

    Stop-Service 'YourServiceName'; Get-CimInstance -ClassName Win32_Service -Filter "Name='YourServiceName'" | Remove-CimInstance
    
  • For v6+, you can use the Remove-Service cmdlet.

Observe that starting in Windows PowerShell 3.0, the cmdlet Get-WmiObject has been superseded by Get-CimInstance.

How to position two elements side by side using CSS

Put the iframe inside the <p> and make the iframe CSS

float:left;

display:inline-block;

Listing files in a directory matching a pattern in Java

Since Java 8 you can use lambdas and achieve shorter code:

File dir = new File(xmlFilesDirectory);
File[] files = dir.listFiles((d, name) -> name.endsWith(".xml"));

How do I set up Vim autoindentation properly for editing Python files?

for more advanced python editing consider installing the simplefold vim plugin. it allows you do advanced code folding using regular expressions. i use it to fold my class and method definitions for faster editing.

How to add line break for UILabel?

In my case also \n was not working, I fixed issue by keeping number of lines to 0 and copied and pasted the text with new line itself for example instead of Hello \n World i pasted

Hello

World

in the interface builder.

How do I use CMake?

I don't know about Windows (never used it), but on a Linux system you just have to create a build directory (in the top source directory)

mkdir build-dir

go inside it

cd build-dir

then run cmake and point to the parent directory

cmake ..

and finally run make

make

Notice that make and cmake are different programs. cmake is a Makefile generator, and the make utility is governed by a Makefile textual file. See cmake & make wikipedia pages.

NB: On Windows, cmake might operate so could need to be used differently. You'll need to read the documentation (like I did for Linux)

How to delete an instantiated object Python?

object.__del__(self) is called when the instance is about to be destroyed.

>>> class Test:
...     def __del__(self):
...         print "deleted"
... 
>>> test = Test()
>>> del test
deleted

Object is not deleted unless all of its references are removed(As quoted by ethan)

Also, From Python official doc reference:

del x doesn’t directly call x.del() — the former decrements the reference count for x by one, and the latter is only called when x‘s reference count reaches zero

How do I import a specific version of a package using go get?

A little cheat sheet on module queries.

To check all existing versions: e.g. go list -m -versions github.com/gorilla/mux

  1. Specific version @v1.2.8
  2. Specific commit @c783230
  3. Specific branch @master
  4. Version prefix @v2
  5. Comparison @>=2.1.5
  6. Latest @latest

E.g. go get github.com/gorilla/[email protected]

Does VBScript have a substring() function?

As Tmdean correctly pointed out you can use the Mid() function. The MSDN Library also has a great reference section on VBScript which you can find here:

VBScript Language Reference (MSDN Library)

JSON Naming Convention (snake_case, camelCase or PascalCase)

In this document Google JSON Style Guide (recommendations for building JSON APIs at Google),

It recommends that:

  1. Property names must be camelCased, ASCII strings.

  2. The first character must be a letter, an underscore (_) or a dollar sign ($).

Example:

{
  "thisPropertyIsAnIdentifier": "identifier value"
}

My team follows this convention.

What does bundle exec rake mean?

It means use rake that bundler is aware of and is part of your Gemfile over any rake that bundler is not aware of and run the db:migrate task.

Convert data file to blob

async function FileToString (file) {
    try {
        let res = await file.raw.text();
        console.log(res);
    } catch (err) {
        throw err;
    }
}

How to get the title of HTML page with JavaScript?

Can use getElementsByTagName

var x = document.getElementsByTagName("title")[0];

alert(x.innerHTML)

// or

alert(x.textContent)

// or

document.querySelector('title')

Edits as suggested by Paul

The project cannot be built until the build path errors are resolved.

This happens when libraries added to the project doesn't have the correct path.

  1. Right click on your project (from package explorer)
  2. Got build path -> configure build path
  3. Select the libraries tab
  4. Fix the path error (give the correct path) by editing jars or classes at fault

How to check if DST (Daylight Saving Time) is in effect, and if so, the offset?

I recently needed to create a date string with UTC and DST, and based on Sheldon's answer I put this together:

_x000D_
_x000D_
Date.prototype.getTimezone = function(showDST) {_x000D_
    var jan = new Date(this.getFullYear(), 0, 1);_x000D_
    var jul = new Date(this.getFullYear(), 6, 1);_x000D_
_x000D_
    var utcOffset = new Date().getTimezoneOffset() / 60 * -1;_x000D_
    var dstOffset = (jan.getTimezoneOffset() - jul.getTimezoneOffset()) / 60;_x000D_
_x000D_
    var utc = "UTC" + utcOffset.getSign() + (utcOffset * 100).preFixed(1000);_x000D_
    var dst = "DST" + dstOffset.getSign() + (dstOffset * 100).preFixed(1000);_x000D_
_x000D_
    if (showDST) {_x000D_
        return utc + " (" + dst + ")";_x000D_
    }_x000D_
_x000D_
    return utc;_x000D_
}_x000D_
Number.prototype.preFixed = function (preCeiling) {_x000D_
    var num = parseInt(this, 10);_x000D_
    if (preCeiling && num < preCeiling) {_x000D_
        num = Math.abs(num);_x000D_
        var numLength   = num.toString().length;_x000D_
        var preCeilingLength = preCeiling.toString().length;_x000D_
        var preOffset   = preCeilingLength - numLength;_x000D_
        for (var i = 0; i < preOffset; i++) {_x000D_
            num = "0" + num;_x000D_
        }_x000D_
    }_x000D_
    return num;_x000D_
}_x000D_
Number.prototype.getSign = function () {_x000D_
    var num  = parseInt(this, 10);_x000D_
    var sign = "+";_x000D_
    if (num < 0) {_x000D_
        sign = "-";_x000D_
    }_x000D_
    return sign;_x000D_
}_x000D_
_x000D_
document.body.innerHTML += new Date().getTimezone() + "<br>";_x000D_
document.body.innerHTML += new Date().getTimezone(true);
_x000D_
<p>Output for Turkey (UTC+0200) and currently in DST: &nbsp; UTC+0300 (DST+0100)</p>_x000D_
<hr>
_x000D_
_x000D_
_x000D_

Apply CSS rules to a nested class inside a div

Use Css Selector for this, or learn more about Css Selector just go here https://www.w3schools.com/cssref/css_selectors.asp

#main_text > .title {
  /* Style goes here */
}

#main_text .title {
  /* Style goes here */
}

Rename MySQL database

In case you need to do that from the command line, just copy, adapt & paste this snippet:

mysql -e "CREATE DATABASE \`new_database\`;"
for table in `mysql -B -N -e "SHOW TABLES;" old_database`
do 
  mysql -e "RENAME TABLE \`old_database\`.\`$table\` to \`new_database\`.\`$table\`"
done
mysql -e "DROP DATABASE \`old_database\`;"

Embed youtube videos that play in fullscreen automatically

This was pretty well answered over here: How to make a YouTube embedded video a full page width one?

If you add '?rel=0&autoplay=1' to the end of the url in the embed code (like this)

<iframe id="video" src="//www.youtube.com/embed/5iiPC-VGFLU?rel=0&autoplay=1" frameborder="0" allowfullscreen></iframe>

of the video it should play on load. Here's a demo over at jsfiddle.

Fast query runs slow in SSRS

I had the same problem, here is my description of the problem

"I created a store procedure which would generate 2200 Rows and would get executed in almost 2 seconds however after calling the store procedure from SSRS 2008 and run the report it actually never ran and ultimately I have to kill the BIDS (Business Intelligence development Studio) from task manager".

What I Tried: I tried running the SP from reportuser Login but SP was running normal for that user as well, I checked Profiler but nothing worked out.

Solution:

Actually the problem is that even though SP is generating the result but SSRS engine is taking time to read these many rows and render it back. So I added WITH RECOMPILE option in SP and ran the report .. this is when miracle happened and my problem got resolve.

VBA Public Array : how to?

Well, basically what I found is that you can declare the array, but when you set it vba shows you an error.

So I put an special sub to declare global variables and arrays, something like:

Global example(10) As Variant

Sub set_values()

example(1) = 1
example(2) = 1
example(3) = 1
example(4) = 1
example(5) = 1
example(6) = 1
example(7) = 1
example(8) = 1
example(9) = 1
example(10) = 1

End Sub

And whenever I want to use the array, I call the sub first, just in case

call set_values

Msgbox example(5)

Perhaps is not the most correct way, but I hope it works for you

C# try catch continue execution

Why cant you use the finally block?

Like

try {

} catch (Exception e) {

  // THIS WILL EXECUTE IF THERE IS AN EXCEPTION IS THROWN IN THE TRY BLOCK

} finally { 

 // THIS WILL EXECUTE IRRESPECTIVE OF WHETHER AN EXCEPTION IS THROWN WITHIN THE TRY CATCH OR NOT

}

EDIT after question amended:

You can do:

int? returnFromFunction2 = null;
    try {
        returnFromFunction2 = function2();
        return returnFromFunction2.value;
        } catch (Exception e) {

          // THIS WILL EXECUTE IF THERE IS AN EXCEPTION IS THROWN IN THE TRY BLOCK

        } finally { 

        if (returnFromFunction2.HasValue) { // do something with value }

         // THIS WILL EXECUTE IRRESPECTIVE OF WHETHER AN EXCEPTION IS THROWN WITHIN THE TRY CATCH OR NOT

        }

WPF ListView turn off selection

Set the style of each ListViewItem to have Focusable set to false.

<ListView ItemsSource="{Binding Test}" >
    <ListView.ItemContainerStyle>
        <Style TargetType="{x:Type ListViewItem}">
            <Setter Property="Focusable" Value="False"/>
        </Style>
    </ListView.ItemContainerStyle>
</ListView>

Algorithm to randomly generate an aesthetically-pleasing color palette

you could have them be within a certain brightness. that would control the ammount of "neon" colors a bit. for instance, if the "brightness"

brightness = sqrt(R^2+G^2+B^2)

was within a certain high bound, it would have a washed out, light color to it. Conversely, if it was within a certain low bound, it would be darker. This would eliminate any crazy, standout colors and if you chose a bound really high or really low, they would all be fairly close to either white or black.

Writing a dictionary to a text file?

For list comprehension lovers, this will write all the key : value pairs in new lines in dog.txt

my_dict = {'foo': [1,2], 'bar':[3,4]}

# create list of strings
list_of_strings = [ f'{key} : {my_dict[key]}' for key in my_dict ]

# write string one by one adding newline
with open('dog.txt', 'w') as my_file:
    [ my_file.write(f'{st}\n') for st in list_of_strings ]

manage.py runserver

I had the same problem and here was my way to solve it:

First, You must know your IP address. On my Windows PC, in the cmd windows i run ipconfig and select my IP V4 address. In my case 192.168.0.13

Second as mention above: runserver 192.168.0.13:8000

It worked for me. The error i did to get the message was the use of the gateway address not my PC address.

Dynamically Fill Jenkins Choice Parameter With Git Branches In a Specified Repo

Extended Choice Parameter plugin will allow you to read the choices from a file.

Of course, now you have another problem: how to make sure the file is up-to-date (that can be done with a post-commit hook) and propagated to all the users (that can be done by placing it on a shared file server). But there may be better solutions.

Show compose SMS view in Android

You can omit tel number for letting user just choose from contacts, but inserting your sms text in the body. Code is for Xamarin Android:

    var uri = Uri.Parse("smsto:"); //append your number here for explicit nb
    var intent = new Intent(Intent.ActionSendto, uri);
    intent.PutExtra("sms_body", text);
    Context.StartActivity(intent);

where

Context is Xamarin.Essentials.Platform.CurrentActivity ?? Application.Context

How to get certain commit from GitHub project

The question title is ambiguous.

jQuery: set selected value of dropdown list?

You can select dropdown option value by name

jQuery("#option_id").find("option:contains('Monday')").each(function()
{
 if( jQuery(this).text() == 'Monday' )
 {
  jQuery(this).attr("selected","selected");
  }
});

Are the decimal places in a CSS width respected?

Although fractional pixels may appear to round up on individual elements (as @SkillDrick demonstrates very well) it's important to know that the fractional pixels are actually respected in the actual box model.

This can best be seen when elements are stacked next to (or on top of) each other; in other words, if I were to place 400 0.5 pixel divs side by side, they would have the same width as a single 200 pixel div. If they all actually rounded up to 1px (as looking at individual elements would imply) we'd expect the 200px div to be half as long.

This can be seen in this runnable code snippet:

_x000D_
_x000D_
body {_x000D_
  color:            white;_x000D_
  font-family:      sans-serif;_x000D_
  font-weight:      bold;_x000D_
  background-color: #334;_x000D_
}_x000D_
_x000D_
.div_house div {_x000D_
  height:           10px;_x000D_
  background-color: orange;_x000D_
  display:          inline-block;_x000D_
}_x000D_
_x000D_
div#small_divs div {_x000D_
  width:            0.5px;_x000D_
}_x000D_
_x000D_
div#large_div div {_x000D_
  width:            200px;_x000D_
}
_x000D_
<div class="div_house" id="small_divs">_x000D_
  <p>0.5px div x 400</p>_x000D_
  <div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div>_x000D_
</div>_x000D_
<br>_x000D_
<div class="div_house" id="large_div">_x000D_
  <p>200px div x 1</p>_x000D_
  <div></div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How do you develop Java Servlets using Eclipse?

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

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

The executable was signed with invalid entitlements

For me that solved it: https://coderwall.com/p/-ckobg

  1. Open Project.xcodeproj > project.pbxproj
  2. Remove all lines like these:
    1. PROVISIONING_PROFILE = ...
    2. "PROVISIONING_PROFILE[sdk=iphoneos*]" = ...
    3. CODE_SIGN_IDENTITY = ...
    4. "CODE_SIGN_IDENTITY[sdk=iphoneos*]" = ...
  3. Set provisioning profiles & code signings for the target again

Entity Framework - Include Multiple Levels of Properties

I made a little helper for Entity Framework 6 (.Net Core style), to include sub-entities in a nice way.

It is on NuGet now : Install-Package ThenInclude.EF6

using System.Data.Entity;

var thenInclude = context.One.Include(x => x.Twoes)
    .ThenInclude(x=> x.Threes)
    .ThenInclude(x=> x.Fours)
    .ThenInclude(x=> x.Fives)
    .ThenInclude(x => x.Sixes)
    .Include(x=> x.Other)
    .ToList();

The package is available on GitHub.

How to read input from console in a batch file?

If you're just quickly looking to keep a cmd instance open instead of exiting immediately, simply doing the following is enough

set /p asd="Hit enter to continue"

at the end of your script and it'll keep the window open.

Note that this'll set asd as an environment variable, and can be replaced with anything else.

Convert spark DataFrame column to python list

Following one liner gives the list you want.

mvv = mvv_count_df.select("mvv").rdd.flatMap(lambda x: x).collect()

jQuery How do you get an image to fade in on load?

Using the examples from Sohnee and karim79. I tested this and it worked in both FF3.6 and IE6.

<script type="text/javascript">
    $(document).ready(function(){
        $("#logo").bind("load", function () { $(this).fadeIn('slow'); });
    });
</script>

<img src="http://www.gimp.org/tutorials/Lite_Quickies/quintet_hst_big.jpg" id="logo" style="display:none"/>

Convert string[] to int[] in one line of code using LINQ

EDIT: to convert to array

int[] asIntegers = arr.Select(s => int.Parse(s)).ToArray();

This should do the trick:

var asIntegers = arr.Select(s => int.Parse(s));

In Matplotlib, what does the argument mean in fig.add_subplot(111)?

enter image description here

import matplotlib.pyplot as plt
plt.figure(figsize=(8,8))
plt.subplot(3,2,1)
plt.subplot(3,2,3)
plt.subplot(3,2,5)
plt.subplot(2,2,2)
plt.subplot(2,2,4)

The first code creates the first subplot in a layout that has 3 rows and 2 columns.

The three graphs in the first column denote the 3 rows. The second plot comes just below the first plot in the same column and so on.

The last two plots have arguments (2, 2) denoting that the second column has only two rows, the position parameters move row wise.

Undefined symbols for architecture x86_64 on Xcode 6.1

Check if that file is included in Build Phases -> Compiled Sources

How to run iPhone emulator WITHOUT starting Xcode?

In the terminal: For Xcode 9.x and above

$ open /Applications/Xcode.app/Contents/Developer/Applications/Simulator.app

For Xcode-beta 9.x and above

$ open /Applications/Xcode-beta.app/Contents/Developer/Applications/Simulator.app

height style property doesn't work in div elements

I'm told that it's bad practice to overuse it, but you can always add !important after your code to prioritize the css properties value.

.p{height:400px!important;}

How to add multiple jar files in classpath in linux

For linux users, you should know the following:

  1. $CLASSPATH is specifically what Java uses to look through multiple directories to find all the different classes it needs for your script (unless you explicitly tell it otherwise with the -cp override). Using -cp (--classpath) requires that you keep track of all the directories manually and copy-paste that line every time you run the program (not preferable IMO).

  2. The colon (":") character separates the different directories. There is only one $CLASSPATH and it has all the directories in it. So, when you run "export CLASSPATH=...." you want to include the current value "$CLASSPATH" in order to append to it. For example:

    export CLASSPATH=.
    export CLASSPATH=$CLASSPATH:/usr/share/java/mysql-connector-java-5.1.12.jar
    

    In the first line above, you start CLASSPATH out with just a simple 'dot' which is the path to your current working directory. With that, whenever you run java it will look in the current working directory (the one you're in) for classes. In the second line above, $CLASSPATH grabs the value that you previously entered (.) and appends the path to a mysql dirver. Now, java will look for the driver AND for your classes.

  3. echo $CLASSPATH
    

    is super handy, and what it returns should read like a colon-separated list of all the directories you want java looking in for what it needs to run your script.

  4. Tomcat does not use CLASSPATH. Read what to do about that here: https://tomcat.apache.org/tomcat-8.0-doc/class-loader-howto.html

error: (-215) !empty() in function detectMultiScale

On OSX with a homebrew install the full path to the opencv folder should work:

face_cascade = cv2.CascadeClassifier('/usr/local/Cellar/opencv/3.4.0_1/share/OpenCV/haarcascades/haarcascade_frontalface_default.xml')
eye_cascade = cv2.CascadeClassifier('/usr/local/Cellar/opencv/3.4.0_1/share/OpenCV/haarcascades/haarcascade_eye.xml')

Take care of the version number in the path.

How to handle notification when app in background in Firebase

The easy way to send messages even if the app is in background and foreground as follow:- To send a message using API, you can use a tool called AdvancedREST Client, its a chrome extension, and send a message with the following parameters.

Rest client tool Link: https://chrome.google.com/webstore/detail/advanced-rest-client/hgmloofddffdnphfgcellkdfbfbjeloo

use this url:- https://fcm.googleapis.com/fcm/send Content-Type:application/json Authorization:key=Your Server key From or Authoization key(see below ref)

{ "data": {
    "image": "https://static.pexels.com/photos/4825/red-love-romantic-flowers.jpg",
    "message": "Firebase Push Message Using API"
    "AnotherActivity": "True"
     },
  "to" : "device id Or Device token"
}

Authorization key can be obtained by visiting Google developers console and click on Credentials button on the left menu for your project. Among the API keys listed, the server key will be your authorization key.

And you need to put tokenID of the receiver in the “to” section of your POST request sent using API.

Hot to get all form elements values using jQuery?

if you want get all values from form in simple array you may be do something like this.

function getValues(form) {
    var listvalues = new Array();
    var datastring = $("#" + form).serializeArray();
    var data = "{";
    for (var x = 0; x < datastring.length; x++) {
        if (data == "{") {
            data += "\"" + datastring[x].name + "\": \"" + datastring[x].value + "\"";
        }
        else {
            data += ",\"" + datastring[x].name + "\": \"" + datastring[x].value + "\"";
        }
    }
    data += "}";
    data = JSON.parse(data);
    listvalues.push(data);
    return listvalues;
};

Array versus linked-list

For me it is like this,

  1. Access

    • Linked Lists allow only sequential access to elements. Thus the algorithmic complexities is order of O(n)
    • Arrays allow random access to its elements and thus the complexity is order of O(1)
  2. Storage

    • Linked lists require an extra storage for references. This makes them impractical for lists of small data items such as characters or boolean values.
    • Arrays do not need an extra storage to point to next data item. Each element can be accessed via indexes.
  3. Size

    • The size of Linked lists are dynamic by nature.
    • The size of array is restricted to declaration.
  4. Insertion/Deletion

    • Elements can be inserted and deleted in linked lists indefinitely.
    • Insertion/Deletion of values in arrays are very expensive. It requires memory reallocation.

mysql error 2005 - Unknown MySQL server host 'localhost'(11001)

I have passed through that error today and did everything described above but didn't work for me. So I decided to view the core problem and logged onto the MySQL root folder in Windows 7 and did this solution:

  1. Go to folder:

    C:\AppServ\MySQL
    
  2. Right click and Run as Administrator these files:

    mysql_servicefix.bat
    
    mysql_serviceinstall.bat
    
    mysql_servicestart.bat
    

Then close the entire explorer window and reopen it or clear cache then login to phpMyAdmin again.

Groovy executing shell commands

To add one more important information to above provided answers -

For a process

def proc = command.execute();

always try to use

def outputStream = new StringBuffer();
proc.waitForProcessOutput(outputStream, System.err)
//proc.waitForProcessOutput(System.out, System.err)

rather than

def output = proc.in.text;

to capture the outputs after executing commands in groovy as the latter is a blocking call (SO question for reason).

How to take a first character from the string

Try this:

Dim s = "RAJAN"
Dim firstChar = s(0)

You can even do this:

Dim firstChar = "RAJAN"(0)

Change auto increment starting number?

Yes, you can use the ALTER TABLE t AUTO_INCREMENT = 42 statement. However, you need to be aware that this will cause the rebuilding of your entire table, at least with InnoDB and certain MySQL versions. If you have an already existing dataset with millions of rows, it could take a very long time to complete.

In my experience, it's better to do the following:

BEGIN WORK;
-- You may also need to add other mandatory columns and values
INSERT INTO t (id) VALUES (42);
ROLLBACK;

In this way, even if you're rolling back the transaction, MySQL will keep the auto-increment value, and the change will be applied instantly.

You can verify this by issuing a SHOW CREATE TABLE t statement. You should see:

> SHOW CREATE TABLE t \G
*************************** 1. row ***************************
       Table: t
Create Table: CREATE TABLE `t` (
...
) ENGINE=InnoDB AUTO_INCREMENT=43 ...

How can I remove the gloss on a select element in Safari on Mac?

As mentioned several times here

-webkit-appearance:none;

also removes the arrows, which is not what you want in most cases.

An easy workaround I found is to simply use select2 instead of select. You can re-style a select2 element as well, and most importantly, select2 looks the same on Windows, Android, iOS and Mac.

javascript convert int to float

JavaScript only has a Number type that stores floating point values.

There is no int.

Edit:

If you want to format the number as a string with two digits after the decimal point use:

(4).toFixed(2)

Replace a string in shell script using a variable

you can use the shell (bash/ksh).

$ var="12345678abc"
$ replace="test"
$ echo ${var//12345678/$replace}
testabc

How to get the date from jQuery UI datepicker

You can retrieve the date by using the getDate function:

$("#datepicker").datepicker( 'getDate' );

The value is returned as a JavaScript Date object.

If you want to use this value when the user selects a date, you can use the onSelect event:

$("#datepicker").datepicker({
   onSelect: function(dateText, inst) { 
      var dateAsString = dateText; //the first parameter of this function
      var dateAsObject = $(this).datepicker( 'getDate' ); //the getDate method
   }
});

The first parameter is in this case the selected Date as String. Use parseDate to convert it to a JS Date Object.

See http://docs.jquery.com/UI/Datepicker for the full jQuery UI DatePicker reference.

Text File Parsing in Java

Have a look at these pages. They contain many open source CSV parsers. JSaPar is one of them.

Short IF - ELSE statement

As others have indicated, something of the form

x ? y : z

is an expression, not a (complete) statement. It is an rvalue which needs to get used someplace - like on the right side of an assignment, or a parameter to a function etc.

Perhaps you could look at this: http://download.oracle.com/javase/tutorial/java/nutsandbolts/expressions.html

Sort tuples based on second parameter

    def findMaxSales(listoftuples):
        newlist = []
        tuple = ()
        for item in listoftuples:
             movie = item[0]
             value = (item[1])
             tuple = value, movie

             newlist += [tuple]
             newlist.sort()
             highest = newlist[-1]
             result = highest[1]
       return result

             movieList = [("Finding Dory", 486), ("Captain America: Civil                      

             War", 408), ("Deadpool", 363), ("Zootopia", 341), ("Rogue One", 529), ("The  Secret Life of Pets", 368), ("Batman v Superman", 330), ("Sing", 268), ("Suicide Squad", 325), ("The Jungle Book", 364)]
             print(findMaxSales(movieList))

output --> Rogue One

How do I create a right click context menu in Java Swing?

I will correct usage for that method that @BullyWillPlaza suggested. Reason is that when I try to add add textArea to only contextMenu it's not visible, and if i add it to both to contextMenu and some panel it ecounters: Different parent double association if i try to switch to Design editor.

TexetObjcet.addMouseListener(new MouseAdapter() {
        @Override
        public void mouseClicked(MouseEvent e) {
            if (SwingUtilities.isRightMouseButton(e)){
                contextmenu.add(TexetObjcet);
                contextmenu.show(TexetObjcet, 0, 0);
            }
        }
    }); 

Make mouse listener like this for text object you need to have popup on. What this will do is when you right click on your text object it will then add that popup and display it. This way you don't encounter that error. Solution that @BullyWillPlaza made is very good, rich and fast to implement in your program so you should try it our see how you like it.

Display current path in terminal only

If you just want to get the information of current directory, you can type:

pwd

and you don't need to use the Nautilus, or you can use a teamviewer software to remote connect to the computer, you can get everything you want.

Save bitmap to location

Create a video thumbnail for a video. It may return null if the video is corrupted or the format is not supported.

private void makeVideoPreview() {
    Bitmap thumbnail = ThumbnailUtils.createVideoThumbnail(videoAbsolutePath, MediaStore.Images.Thumbnails.MINI_KIND);
    saveImage(thumbnail);
}

To Save your bitmap in sdcard use the following code

Store Image

private void storeImage(Bitmap image) {
    File pictureFile = getOutputMediaFile();
    if (pictureFile == null) {
        Log.d(TAG,
                "Error creating media file, check storage permissions: ");// e.getMessage());
        return;
    } 
    try {
        FileOutputStream fos = new FileOutputStream(pictureFile);
        image.compress(Bitmap.CompressFormat.PNG, 90, fos);
        fos.close();
    } catch (FileNotFoundException e) {
        Log.d(TAG, "File not found: " + e.getMessage());
    } catch (IOException e) {
        Log.d(TAG, "Error accessing file: " + e.getMessage());
    }  
}

To Get the Path for Image Storage

/** Create a File for saving an image or video */
private  File getOutputMediaFile(){
    // To be safe, you should check that the SDCard is mounted
    // using Environment.getExternalStorageState() before doing this. 
    File mediaStorageDir = new File(Environment.getExternalStorageDirectory()
            + "/Android/data/"
            + getApplicationContext().getPackageName()
            + "/Files"); 

    // This location works best if you want the created images to be shared
    // between applications and persist after your app has been uninstalled.

    // Create the storage directory if it does not exist
    if (! mediaStorageDir.exists()){
        if (! mediaStorageDir.mkdirs()){
            return null;
        }
    } 
    // Create a media file name
    String timeStamp = new SimpleDateFormat("ddMMyyyy_HHmm").format(new Date());
    File mediaFile;
        String mImageName="MI_"+ timeStamp +".jpg";
        mediaFile = new File(mediaStorageDir.getPath() + File.separator + mImageName);  
    return mediaFile;
} 

SQL Error: ORA-00922: missing or invalid option

You should not use space character while naming database objects. Even though it's possible by using double quotes(quoted identifiers), CREATE TABLE "chartered flight" ..., it's not recommended. Take a closer look here

How do I format a number with commas in T-SQL?

This belongs in a comment to Phil Hunt's answer but alas I don't have the rep.

To strip the ".00" off the end of your number string, parsename is super-handy. It tokenizes period-delimited strings and returns the specified element, starting with the rightmost token as element 1.

SELECT PARSENAME(CONVERT(varchar, CAST(987654321 AS money), 1), 2)

Yields "987,654,321"

Simple working Example of json.net in VB.net

Imports Newtonsoft.Json.Linq

Dim json As JObject = JObject.Parse(Me.TextBox1.Text)
MsgBox(json.SelectToken("Venue").SelectToken("ID"))

Javascript - How to extract filename from a file input control

None of the above answers worked for me, here is my solution which updates a disabled input with the filename:

<script type="text/javascript"> 
  document.getElementById('img_name').onchange = function () {
  var filePath = this.value;
    if (filePath) {
      var fileName = filePath.replace(/^.*?([^\\\/]*)$/, '$1');
      document.getElementById('img_name_input').value = fileName;
    }
  };
</script>

Making interface implementations async

Better solution is to introduce another interface for async operations. New interface must inherit from original interface.

Example:

interface IIO
{
    void DoOperation();
}

interface IIOAsync : IIO
{
    Task DoOperationAsync();
}


class ClsAsync : IIOAsync
{
    public void DoOperation()
    {
        DoOperationAsync().GetAwaiter().GetResult();
    }

    public async Task DoOperationAsync()
    {
        //just an async code demo
        await Task.Delay(1000);
    }
}


class Program
{
    static void Main(string[] args)
    {
        IIOAsync asAsync = new ClsAsync();
        IIO asSync = asAsync;

        Console.WriteLine(DateTime.Now.Second);

        asAsync.DoOperation();
        Console.WriteLine("After call to sync func using Async iface: {0}", 
            DateTime.Now.Second);

        asAsync.DoOperationAsync().GetAwaiter().GetResult();
        Console.WriteLine("After call to async func using Async iface: {0}", 
            DateTime.Now.Second);

        asSync.DoOperation();
        Console.WriteLine("After call to sync func using Sync iface: {0}", 
            DateTime.Now.Second);

        Console.ReadKey(true);
    }
}

P.S. Redesign your async operations so they return Task instead of void, unless you really must return void.

Add new column with foreign key constraint in one command

In Oracle :

ALTER TABLE one ADD two_id INTEGER CONSTRAINT Fk_two_id REFERENCES two(id);

Python - How do you run a .py file?

If you want to run .py files in Windows, Try installing Git bash Then download python(Required Version) from python.org and install in the main c drive folder

For me, its :

"C:\Python38"

then open Git Bash and go to the respective folder where your .py file is stored :

For me, its :

File Location : "Downloads" File Name : Train.py

So i changed my Current working Directory From "C:/User/(username)/" to "C:/User/(username)/Downloads"

then i will run the below command

" /c/Python38/python Train.py "

and it will run successfully.

But if it give the below error :

from sklearn.model_selection import train_test_split ModuleNotFoundError: No module named 'sklearn'

Then Do not panic :

and use this command :

" /c/Python38/Scripts/pip install sklearn "

and after it has installed sklearn go back and run the previous command :

" /c/Python38/python Train.py "

and it will run successfully.

!!!!HAPPY LEARNING !!!!

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

You can do

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

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

What exactly is nullptr?

nullptr can't be assigned to an integral type such as an int but only a pointer type; either a built-in pointer type such as int *ptr or a smart pointer such as std::shared_ptr<T>

I believe this is an important distinction because NULL can still be assigned to both an integral type and a pointer as NULL is a macro expanded to 0 which can serve as both an initial value for an int as well as a pointer.

No plot window in matplotlib

Modern IPython uses the "--matplotlib" argument with an optional backend parameter. It defaults to "auto", which is usually good enough on Mac and Windows. I haven't tested it on Ubuntu or any other Linux distribution, but I would expect it to work.

ipython --matplotlib

Sort ObservableCollection<string> through C#

The argument to OrderByDescending is a function returning a key to sort with. In your case, the key is the string itself:

var result = _animals.OrderByDescending(a => a);

If you wanted to sort by length for example, you'll write:

var result = _animals.OrderByDescending(a => a.Length);

Missing maven .m2 folder

Check the configurations in {M2_HOME}\conf\setting.xml as mentioned in the following link.

http://www.mkyong.com/maven/where-is-maven-local-repository/

Hope this helps.

Could not load type 'XXX.Global'

Removing Language="c#" in global.asax file resolved the issue for me.

Adding n hours to a date in Java?

Date argDate = new Date(); //set your date.
String argTime = "09:00"; //9 AM - 24 hour format :- Set your time.
SimpleDateFormat sdf = new SimpleDateFormat("dd-MMM-yyyy");
SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy HH:mm");
String dateTime = sdf.format(argDate) + " " + argTime;
Date requiredDate = dateFormat.parse(dateTime);

Where Is Machine.Config?

In your asp.net app use this

using System.Configuration;
Response.Write(ConfigurationManager.OpenMachineConfiguration().FilePath);

Case statement with multiple values in each 'when' block

In a case statement, a , is the equivalent of || in an if statement.

case car
   when 'toyota', 'lexus'
      # code
end

Some other things you can do with a Ruby case statement

Calculating Page Load Time In JavaScript

Why so complicated? When you can do:

var loadTime = window.performance.timing.domContentLoadedEventEnd- window.performance.timing.navigationStart;

If you need more times check out the window.performance object:

console.log(window.performance);

Will show you the timing object:

connectEnd                 Time when server connection is finished.
connectStart               Time just before server connection begins.
domComplete                Time just before document readiness completes.
domContentLoadedEventEnd   Time after DOMContentLoaded event completes.
domContentLoadedEventStart Time just before DOMContentLoaded starts.
domInteractive             Time just before readiness set to interactive.
domLoading                 Time just before readiness set to loading.
domainLookupEnd            Time after domain name lookup.
domainLookupStart          Time just before domain name lookup.
fetchStart                 Time when the resource starts being fetched.
loadEventEnd               Time when the load event is complete.
loadEventStart             Time just before the load event is fired.
navigationStart            Time after the previous document begins unload.
redirectCount              Number of redirects since the last non-redirect.
redirectEnd                Time after last redirect response ends.
redirectStart              Time of fetch that initiated a redirect.
requestStart               Time just before a server request.
responseEnd                Time after the end of a response or connection.
responseStart              Time just before the start of a response.
timing                     Reference to a performance timing object.
navigation                 Reference to performance navigation object.
performance                Reference to performance object for a window.
type                       Type of the last non-redirect navigation event.
unloadEventEnd             Time after the previous document is unloaded.
unloadEventStart           Time just before the unload event is fired.

Browser Support

More Info

How do I get Fiddler to stop ignoring traffic to localhost?

  • Type ipconfig at the commmand prompt.
  • It will give you your IPv4 Address
  • Replace localhost with your IPv4 Address in the Url when hitting the service.

The traffic will show up in Fiddler under your computer's IP address.

Difference between FetchType LAZY and EAGER in Java Persistence API?

The main difference between the two types of fetching is a moment when data gets loaded into a memory.
I have attached 2 photos to help you understand this.

Eager fetch
 Eager fetch

Lazy fetch Lazy fetch

Spring: How to inject a value to static field?

Spring uses dependency injection to populate the specific value when it finds the @Value annotation. However, instead of handing the value to the instance variable, it's handed to the implicit setter instead. This setter then handles the population of our NAME_STATIC value.

    @RestController 
//or if you want to declare some specific use of the properties file then use
//@Configuration
//@PropertySource({"classpath:application-${youeEnvironment}.properties"})
public class PropertyController {

    @Value("${name}")//not necessary
    private String name;//not necessary

    private static String NAME_STATIC;

    @Value("${name}")
    public void setNameStatic(String name){
        PropertyController.NAME_STATIC = name;
    }
}

Integrating Dropzone.js into existing HTML form with other fields

This is just another example of how you can use Dropzone.js in an existing form.

dropzone.js :

 init: function() {

   this.on("success", function(file, responseText) {
     //alert("HELLO ?" + responseText); 
     mylittlefix(responseText);
   });

   return noop;
 },

Then, later in the file I put

function mylittlefix(responseText) {
  $('#botofform').append('<input type="hidden" name="files[]" value="'+ responseText +'">');
}

This assumes you have a div with id #botofform that way when uploading you can use the uploaded files' names.

Note: my upload script returned theuploadedfilename.jpeg dubblenote you also would need to make a cleanup script that checks the upload directory for files not in use and deletes them ..if in a front end non authenticated form :)

How to format a Java string with leading zero?

public class LeadingZerosExample {
    public static void main(String[] args) {
       int number = 1500;

       // String format below will add leading zeros (the %0 syntax) 
       // to the number above. 
       // The length of the formatted string will be 7 characters.

       String formatted = String.format("%07d", number);

       System.out.println("Number with leading zeros: " + formatted);
    }
}

Stop Chrome Caching My JS Files

  1. Open Developer Tools

    • Either F12
    • Or ... -> More Tools -> Developer Tools
  2. Click Empty Cache and Hard Reload

    • Either right-click refresh icon (just left to url address bar)
    • Or left-click refresh icon and holding it for 1 second

PHP include relative path

function relativepath($to){
    $a=explode("/",$_SERVER["PHP_SELF"] );
    $index= array_search("$to",$a);
    $str=""; 
    for ($i = 0; $i < count($a)-$index-2; $i++) {
        $str.= "../";
    }
    return $str;
    }

Here is the best solution i made about that, you just need to specify at which level you want to stop, but the problem is that you have to use this folder name one time.

A long bigger than Long.MAX_VALUE

You can't. If you have a method called isBiggerThanMaxLong(long) it should always return false.

If you were to increment the bits of Long.MAX_VALUE, the next value should be Long.MIN_VALUE. Read up on twos-complement and that should tell you why.

Check if datetime instance falls in between other two datetime objects

Write yourself a Helper function:

public static bool IsBewteenTwoDates(this DateTime dt, DateTime start, DateTime end)
{
    return dt >= start && dt <= end;
}

Then call: .IsBewteenTwoDates(DateTime.Today ,new DateTime(,,));

Accessing a Shared File (UNC) From a Remote, Non-Trusted Domain With Credentials

I looked to MS to find the answers. The first solution assumes the user account running the application process has access to the shared folder or drive (Same domain). Make sure your DNS is resolved or try using IP address. Simply do the following:

 DirectoryInfo di = new DirectoryInfo(PATH);
 var files = di.EnumerateFiles("*.*", SearchOption.AllDirectories);

If you want across different domains .NET 2.0 with credentials follow this model:

WebRequest req = FileWebRequest.Create(new Uri(@"\\<server Name>\Dir\test.txt"));

        req.Credentials = new NetworkCredential(@"<Domain>\<User>", "<Password>");
        req.PreAuthenticate = true;

        WebResponse d = req.GetResponse();
        FileStream fs = File.Create("test.txt");

        // here you can check that the cast was successful if you want. 
        fs = d.GetResponseStream() as FileStream;
        fs.Close();

AngularJS - Passing data between pages

What you should do is create a service to share data between controllers.

Nice tutorial https://www.youtube.com/watch?v=HXpHV5gWgyk

Replace special characters in a string with _ (underscore)

string = string.replace(/[&\/\\#,+()$~%.'":*?<>{}]/g,'_');

Alternatively, to change all characters except numbers and letters, try:

string = string.replace(/[^a-zA-Z0-9]/g,'_');

Center a 'div' in the middle of the screen, even when the page is scrolled up or down?

Correct Method is

.PopupPanel
{
    border: solid 1px black;
    position: fixed;
    left: 50%;
    top: 50%;
    background-color: white;
    z-index: 100;
    height: 400px;
    margin-top: -200px;

    width: 600px;
    margin-left: -300px;
}

Visual Studio 2015 or 2017 does not discover unit tests

  • Check out, if NUnit Test Adapter 2/3 is installed in VisualStudio.
    (Tools>Extensions and Updates )

  • Make sure that correct processor architecture is chosen:
    (Test>Test Settings>Default Processor Architecture)

Compare two DataFrames and output their differences side-by-side

If you found this thread trying to compare data fames in tests, then take a look at assert_frame_equal method: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.testing.assert_frame_equal.html

How to save a Seaborn plot into a file

This works for me

import seaborn as sns
import matplotlib.pyplot as plt
%matplotlib inline

sns.factorplot(x='holiday',data=data,kind='count',size=5,aspect=1)
plt.savefig('holiday-vs-count.png')

Serializing enums with Jackson

In Spring Boot 2, the easiest way is to declare in your application.properties:

spring.jackson.serialization.WRITE_ENUMS_USING_TO_STRING=true
spring.jackson.deserialization.READ_ENUMS_USING_TO_STRING=true

and define the toString() method of your enums.

Which Android IDE is better - Android Studio or Eclipse?

Working with Eclipse can be difficult at times, probably when debugging and designing layouts Eclipse sometimes get stuck and we have to restart Eclipse from time to time. Also you get problems with emulators.

Android studio was released very recently and this IDE is not yet heavily used by developers. Therefore, it may contain certain bugs.

This describes the difference between android android studio and eclipse project structure: Android Studio Project Structure (v.s. Eclipse Project Structure)

This teaches you how to use the android studio: http://www.infinum.co/the-capsized-eight/articles/android-studio-vs-eclipse-1-0

Configure hibernate (using JPA) to store Y/N for type Boolean instead of 0/1

To even do better boolean mapping to Y/N, add to your hibernate configuration:

<!-- when using type="yes_no" for booleans, the line below allow booleans in HQL expressions: -->
<property name="hibernate.query.substitutions">true 'Y', false 'N'</property>

Now you can use booleans in HQL, for example:

"FROM " + SomeDomainClass.class.getName() + " somedomainclass " +
"WHERE somedomainclass.someboolean = false"

Concatenating two one-dimensional NumPy arrays

The line should be:

numpy.concatenate([a,b])

The arrays you want to concatenate need to be passed in as a sequence, not as separate arguments.

From the NumPy documentation:

numpy.concatenate((a1, a2, ...), axis=0)

Join a sequence of arrays together.

It was trying to interpret your b as the axis parameter, which is why it complained it couldn't convert it into a scalar.

Merging two arrays in .NET

I'm assuming you're using your own array types as opposed to the built-in .NET arrays:

public string[] merge(input1, input2)
{
    string[] output = new string[input1.length + input2.length];
    for(int i = 0; i < output.length; i++)
    {
        if (i >= input1.length)
            output[i] = input2[i-input1.length];
        else
            output[i] = input1[i];
    }
    return output;
}

Another way of doing this would be using the built in ArrayList class.

public ArrayList merge(input1, input2)
{
    Arraylist output = new ArrayList();
    foreach(string val in input1)
        output.add(val);
    foreach(string val in input2)
        output.add(val);
    return output;
}

Both examples are C#.

How to trace the path in a Breadth-First Search?

I like both @Qiao first answer and @Or's addition. For a sake of a little less processing I would like to add to Or's answer.

In @Or's answer keeping track of visited node is great. We can also allow the program to exit sooner that it currently is. At some point in the for loop the current_neighbour will have to be the end, and once that happens the shortest path is found and program can return.

I would modify the the method as follow, pay close attention to the for loop

graph = {
1: [2, 3, 4],
2: [5, 6],
3: [10],
4: [7, 8],
5: [9, 10],
7: [11, 12],
11: [13]
}


    def bfs(graph_to_search, start, end):
        queue = [[start]]
        visited = set()

    while queue:
        # Gets the first path in the queue
        path = queue.pop(0)

        # Gets the last node in the path
        vertex = path[-1]

        # Checks if we got to the end
        if vertex == end:
            return path
        # We check if the current node is already in the visited nodes set in order not to recheck it
        elif vertex not in visited:
            # enumerate all adjacent nodes, construct a new path and push it into the queue
            for current_neighbour in graph_to_search.get(vertex, []):
                new_path = list(path)
                new_path.append(current_neighbour)
                queue.append(new_path)

                #No need to visit other neighbour. Return at once
                if current_neighbour == end
                    return new_path;

            # Mark the vertex as visited
            visited.add(vertex)


print bfs(graph, 1, 13)

The output and everything else will be the same. However, the code will take less time to process. This is especially useful on larger graphs. I hope this helps someone in the future.

What is a daemon thread in Java?

Here is an example to test behavior of daemon threads in case of jvm exit due to non existence of user threads.

Please note second last line in the output below, when main thread exited, daemon thread also died and did not print finally executed9 statement within finally block. This means that any i/o resources closed within finally block of a daemon thread will not be closed if JVM exits due to non existence of user threads.

public class DeamonTreadExample {

public static void main(String[] args) throws InterruptedException {

    Thread t = new Thread(() -> {
        int count = 0;
        while (true) {
            count++;
            try {
                System.out.println("inside try"+ count);
                Thread.currentThread().sleep(1000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } finally {
                System.out.println("finally executed"+ count);
            }
        }
    });
    t.setDaemon(true);
    t.start();

    Thread.currentThread().sleep(10000);
    System.out.println("main thread exited");
  }
}

Output

inside try1
finally executed1
inside try2
finally executed2
inside try3
finally executed3
inside try4
finally executed4
inside try5
finally executed5
inside try6
finally executed6
inside try7
finally executed7
inside try8
finally executed8
inside try9
finally executed9
inside try10
main thread exited

How can you determine a point is between two other points on a line segment?

Using a more geometric approach, calculate the following distances:

ab = sqrt((a.x-b.x)**2 + (a.y-b.y)**2)
ac = sqrt((a.x-c.x)**2 + (a.y-c.y)**2)
bc = sqrt((b.x-c.x)**2 + (b.y-c.y)**2)

and test whether ac+bc equals ab:

is_on_segment = abs(ac + bc - ab) < EPSILON

That's because there are three possibilities:

  • The 3 points form a triangle => ac+bc > ab
  • They are collinear and c is outside the ab segment => ac+bc > ab
  • They are collinear and c is inside the ab segment => ac+bc = ab

Passing just a type as a parameter in C#

foo.GetColumnValues(dm.mainColumn, typeof(string))

Alternatively, you could use a generic method:

public void GetColumnValues<T>(object mainColumn)
{
    GetColumnValues(mainColumn, typeof(T));
}

and you could then use it like:

foo.GetColumnValues<string>(dm.mainColumn);

I can't understand why this JAXB IllegalAnnotationException is thrown

The exception is due to your JAXB (JSR-222) implementation believing that there are two things mapped with the same name (a field and a property). There are a couple of options for your use case:

OPTION #1 - Annotate the Field with @XmlAccessorType(XmlAccessType.FIELD)

If you want to annotation the field then you should specify @XmlAccessorType(XmlAccessType.FIELD)

Fields.java:

package forum10795793;

import java.util.*;
import javax.xml.bind.annotation.*;

@XmlRootElement(name = "fields")
@XmlAccessorType(XmlAccessType.FIELD)
public class Fields {

    @XmlElement(name = "field")
    List<Field> fields = new ArrayList<Field>();

    public List<Field> getFields() {
        return fields;
    }

    public void setFields(List<Field> fields) {
        this.fields = fields;
    }

}

Field.java:

package forum10795793;

import javax.xml.bind.annotation.*;

@XmlAccessorType(XmlAccessType.FIELD)
public class Field {

    @XmlAttribute(name = "mappedField")
    String mappedField;

    public String getMappedField() {
        return mappedField;
    }

    public void setMappedField(String mappedField) {
        this.mappedField = mappedField;
    }

}

OPTION #2 - Annotate the Properties

The default accessor type is XmlAccessType.PUBLIC. This means that by default JAXB implementations will map public fields and accessors to XML. Using the default setting you should annotate the public accessors where you want to override the default mapping behaviour.

Fields.java:

package forum10795793;

import java.util.*;
import javax.xml.bind.annotation.*;

@XmlRootElement(name = "fields")
public class Fields {

    List<Field> fields = new ArrayList<Field>();

    @XmlElement(name = "field")
    public List<Field> getFields() {
        return fields;
    }

    public void setFields(List<Field> fields) {
        this.fields = fields;
    }

}

Field.java:

package forum10795793;

import javax.xml.bind.annotation.*;

public class Field {

    String mappedField;

    @XmlAttribute(name = "mappedField")
    public String getMappedField() {
        return mappedField;
    }

    public void setMappedField(String mappedField) {
        this.mappedField = mappedField;
    }

}

For More Information

Two-way SSL clarification

Both certificates should exist prior to the connection. They're usually created by Certification Authorities (not necessarily the same). (There are alternative cases where verification can be done differently, but some verification will need to be made.)

The server certificate should be created by a CA that the client trusts (and following the naming conventions defined in RFC 6125).

The client certificate should be created by a CA that the server trusts.

It's up to each party to choose what it trusts.

There are online CA tools that will allow you to apply for a certificate within your browser and get it installed there once the CA has issued it. They need not be on the server that requests client-certificate authentication.

The certificate distribution and trust management is the role of the Public Key Infrastructure (PKI), implemented via the CAs. The SSL/TLS client and servers and then merely users of that PKI.

When the client connects to a server that requests client-certificate authentication, the server sends a list of CAs it's willing to accept as part of the client-certificate request. The client is then able to send its client certificate, if it wishes to and a suitable one is available.

The main advantages of client-certificate authentication are:

  • The private information (the private key) is never sent to the server. The client doesn't let its secret out at all during the authentication.
  • A server that doesn't know a user with that certificate can still authenticate that user, provided it trusts the CA that issued the certificate (and that the certificate is valid). This is very similar to the way passports are used: you may have never met a person showing you a passport, but because you trust the issuing authority, you're able to link the identity to the person.

You may be interested in Advantages of client certificates for client authentication? (on Security.SE).

Numpy where function multiple conditions

This should work:

dists[((dists >= r) & (dists <= r+dr))]

The most elegant way~~

Long vs Integer, long vs int, what to use and when?

Long is the Object form of long, and Integer is the object form of int.

The long uses 64 bits. The int uses 32 bits, and so can only hold numbers up to ±2 billion (-231 to +231-1).

You should use long and int, except where you need to make use of methods inherited from Object, such as hashcode. Java.util.collections methods usually use the boxed (Object-wrapped) versions, because they need to work for any Object, and a primitive type, like int or long, is not an Object.

Another difference is that long and int are pass-by-value, whereas Long and Integer are pass-by-reference value, like all non-primitive Java types. So if it were possible to modify a Long or Integer (it's not, they're immutable without using JNI code), there would be another reason to use one over the other.

A final difference is that a Long or Integer could be null.

An error occurred while updating the entries. See the inner exception for details

Click "View Detail..." a window will open where you can expand the "Inner Exception" my guess is that when you try to delete the record there is a reference constraint violation. The inner exception will give you more information on that so you can modify your code to remove any references prior to deleting the record.

enter image description here

How can I catch all the exceptions that will be thrown through reading and writing a file?

You may catch multiple exceptions in single catch block.

try{
  // somecode throwing multiple exceptions;
} catch (Exception1 | Exception2 | Exception3 exception){
  // handle exception.
} 

Accessing Imap in C#

There is no .NET framework support for IMAP. You'll need to use some 3rd party component.

Try https://www.limilabs.com/mail, it's very affordable and easy to use, it also supports SSL:

using(Imap imap = new Imap())
{
    imap.ConnectSSL("imap.company.com");
    imap.Login("user", "password");

    imap.SelectInbox();
    List<long> uids = imap.SearchFlag(Flag.Unseen);
    foreach (long uid in uids)
    {
        string eml = imap.GetMessageByUID(uid);
        IMail message = new MailBuilder()
            .CreateFromEml(eml);

        Console.WriteLine(message.Subject);
        Console.WriteLine(message.TextDataString);
    }
    imap.Close(true);
}

Please note that this is a commercial product I've created.

You can download it here: https://www.limilabs.com/mail.

How to find length of a string array?

String car [];

is a reference to an array of String-s. You can't see a length because there is no array there!

How can I enable CORS on Django REST Framework

Django=2.2.12 django-cors-headers=3.2.1 djangorestframework=3.11.0

Follow the official instruction doesn't work

Finally use the old way to figure it out.

ADD:

# proj/middlewares.py
from rest_framework.authentication import SessionAuthentication


class CsrfExemptSessionAuthentication(SessionAuthentication):

    def enforce_csrf(self, request):
        return  # To not perform the csrf check previously happening

#proj/settings.py

REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES': (
        'proj.middlewares.CsrfExemptSessionAuthentication',
    ),
}

Difference between INNER JOIN and LEFT SEMI JOIN

Tried in Hive and got the below output

table1

1,wqe,chennai,india

2,stu,salem,india

3,mia,bangalore,india

4,yepie,newyork,USA

table2

1,wqe,chennai,india

2,stu,salem,india

3,mia,bangalore,india

5,chapie,Los angels,USA

Inner Join

SELECT * FROM table1 INNER JOIN table2 ON (table1.id = table2.id);

1 wqe chennai india 1 wqe chennai india

2 stu salem india 2 stu salem india

3 mia bangalore india 3 mia bangalore india

Left Join

SELECT * FROM table1 LEFT JOIN table2 ON (table1.id = table2.id);

1 wqe chennai india 1 wqe chennai india

2 stu salem india 2 stu salem india

3 mia bangalore india 3 mia bangalore india

4 yepie newyork USA NULL NULL NULL NULL

Left Semi Join

SELECT * FROM table1 LEFT SEMI JOIN table2 ON (table1.id = table2.id);

1 wqe chennai india

2 stu salem india

3 mia bangalore india

note: Only records in left table are displayed whereas for Left Join both the table records displayed

Auto select file in Solution Explorer from its open tab

In Visual Studio 2012, the same can be done using the "Sync With Active Document" option in Solution Explorer

Non greedy (reluctant) regex matching in sed?

With sed, I usually implement non-greedy search by searching for anything except the separator until the separator :

echo "http://www.suon.co.uk/product/1/7/3/" | sed -n 's;\(http://[^/]*\)/.*;\1;p'

Output:

http://www.suon.co.uk

this is:

  • don't output -n
  • search, match pattern, replace and print s/<pattern>/<replace>/p
  • use ; search command separator instead of / to make it easier to type so s;<pattern>;<replace>;p
  • remember match between brackets \( ... \), later accessible with \1,\2...
  • match http://
  • followed by anything in brackets [], [ab/] would mean either a or b or /
  • first ^ in [] means not, so followed by anything but the thing in the []
  • so [^/] means anything except / character
  • * is to repeat previous group so [^/]* means characters except /.
  • so far sed -n 's;\(http://[^/]*\) means search and remember http://followed by any characters except / and remember what you've found
  • we want to search untill the end of domain so stop on the next / so add another / at the end: sed -n 's;\(http://[^/]*\)/' but we want to match the rest of the line after the domain so add .*
  • now the match remembered in group 1 (\1) is the domain so replace matched line with stuff saved in group \1 and print: sed -n 's;\(http://[^/]*\)/.*;\1;p'

If you want to include backslash after the domain as well, then add one more backslash in the group to remember:

echo "http://www.suon.co.uk/product/1/7/3/" | sed -n 's;\(http://[^/]*/\).*;\1;p'

output:

http://www.suon.co.uk/

Unprotect workbook without password

No longer works for spreadsheets Protected with Excel 2013 or later -- they improved the pw hash. So now need to unzip .xlsx and hack the internals.

How to use SqlClient in ASP.NET Core?

I think you may have missed this part in the tutorial:

Instead of referencing System.Data and System.Data.SqlClient you need to grab from Nuget:

System.Data.Common and System.Data.SqlClient.

Currently this creates dependency in project.json –> aspnetcore50 section to these two libraries.

"aspnetcore50": {
       "dependencies": {
           "System.Runtime": "4.0.20-beta-22523",
           "System.Data.Common": "4.0.0.0-beta-22605",
           "System.Data.SqlClient": "4.0.0.0-beta-22605"
       }
}

Try getting System.Data.Common and System.Data.SqlClient via Nuget and see if this adds the above dependencies for you, but in a nutshell you are missing System.Runtime.

Edit: As per Mozarts answer, if you are using .NET Core 3+, reference Microsoft.Data.SqlClient instead.

Among $_REQUEST, $_GET and $_POST which one is the fastest?

You are prematurely optimizing. Also, you should really put some thought into whether GET should be used for stuff you're POST-ing, for security reasons.

PHP read and write JSON from file

The clue is in the error message - if you look at the documentation for json_decode note that it can take a second param, which controls whether it returns an array or an object - it defaults to object.

So change your call to

$json = json_decode(file_get_contents($file), true);

And it'll return an associative array and your code should work fine.

HTML5 validation when the input type is not "submit"

I may be late, but the way I did it was to create a hidden submit input, and calling it's click handler upon submit. Something like (using jquery for simplicity):

<input type="text" id="example" name="example" value="" required>
<button type="button"  onclick="submitform()" id="save">Save</button>
<input id="submit_handle" type="submit" style="display: none">

<script>
function submitform() {
    $('#submit_handle').click();
}
</script>

How to reload the current state?

$scope.reloadstat = function () { $state.go($state.current, {}, {reload: true}); };

Proxies with Python 'Requests' module

I share some code how to fetch proxies from the site "https://free-proxy-list.net" and store data to a file compatible with tools like "Elite Proxy Switcher"(format IP:PORT):

##PROXY_UPDATER - get free proxies from https://free-proxy-list.net/

from lxml.html import fromstring
import requests
from itertools import cycle
import traceback
import re

######################FIND PROXIES#########################################
def get_proxies():
    url = 'https://free-proxy-list.net/'
    response = requests.get(url)
    parser = fromstring(response.text)
    proxies = set()
    for i in parser.xpath('//tbody/tr')[:299]:   #299 proxies max
        proxy = ":".join([i.xpath('.//td[1]/text()') 
        [0],i.xpath('.//td[2]/text()')[0]])
        proxies.add(proxy)
    return proxies



######################write to file in format   IP:PORT######################
try:
    proxies = get_proxies()
    f=open('proxy_list.txt','w')
    for proxy in proxies:
        f.write(proxy+'\n')
    f.close()
    print ("DONE")
except:
    print ("MAJOR ERROR")

What is the difference between resource and endpoint?

Consider a server which has the information of users, missions and their reward points.

  1. Users and Reward Points are the resources
  2. An end point can relate to more than one resource
  3. Endpoints can be described using either a description or a full or partial URL

enter image description here

Source: API Endpoints vs Resources

Javascript Get Element by Id and set the value

I think the problem is the way you call your javascript function. Your code is like so:

<input type="button" onclick="javascript: myFunc(myID)" value="button"/>

myID should be wrapped in quotes.

PHP compare time

To see of the curent time is greater or equal to 14:08:10 do this:

if (time() >= strtotime("14:08:10")) {
  echo "ok";
}

Depending on your input sources, make sure to account for timezone.

See PHP time() and PHP strtotime()

Return generated pdf using spring MVC

You were on the right track with response.getOutputStream(), but you're not using its output anywhere in your code. Essentially what you need to do is to stream the PDF file's bytes directly to the output stream and flush the response. In Spring you can do it like this:

@RequestMapping(value="/getpdf", method=RequestMethod.POST)
public ResponseEntity<byte[]> getPDF(@RequestBody String json) {
    // convert JSON to Employee 
    Employee emp = convertSomehow(json);

    // generate the file
    PdfUtil.showHelp(emp);

    // retrieve contents of "C:/tmp/report.pdf" that were written in showHelp
    byte[] contents = (...);

    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(MediaType.APPLICATION_PDF);
    // Here you have to set the actual filename of your pdf
    String filename = "output.pdf";
    headers.setContentDispositionFormData(filename, filename);
    headers.setCacheControl("must-revalidate, post-check=0, pre-check=0");
    ResponseEntity<byte[]> response = new ResponseEntity<>(contents, headers, HttpStatus.OK);
    return response;
}

Notes:

  • use meaningful names for your methods: naming a method that writes a PDF document showHelp is not a good idea
  • reading a file into a byte[]: example here
  • I'd suggest adding a random string to the temporary PDF file name inside showHelp() to avoid overwriting the file if two users send a request at the same time

ASP.NET GridView RowIndex As CommandArgument

I think this will work.

<gridview>
<Columns>

            <asp:ButtonField  ButtonType="Button" CommandName="Edit" Text="Edit" Visible="True" CommandArgument="<%# Container.DataItemIndex %>" />
        </Columns>
</gridview>

What is the difference between Eclipse for Java (EE) Developers and Eclipse Classic?

If you want to build Java EE applications, it's best to use Eclipse IDE for Java EE. It has editors from HTML to JSP/JSF, Javascript. It's rich for webapps development, and provide plugins and tools to develop Java EE applications easily (all bundled).

Eclipse Classic is basically the full featured Eclipse without the Java EE part.

PHP removing a character in a string

I think that it's better to use simply str_replace, like the manual says:

If you don't need fancy replacing rules (like regular expressions), you should always use this function instead of ereg_replace() or preg_replace().

<?
$badUrl = "http://www.site.com/backend.php?/c=crud&m=index&t=care";
$goodUrl = str_replace('?/', '?', $badUrl);

Join two data frames, select all columns from one and some columns from the other

Here is a solution that does not require a SQL context, but maintains the metadata of a DataFrame.

a = sc.parallelize([['a', 'foo'], ['b', 'hem'], ['c', 'haw']]).toDF(['a_id', 'extra'])
b = sc.parallelize([['p1', 'a'], ['p2', 'b'], ['p3', 'c']]).toDF(["other", "b_id"])

c = a.join(b, a.a_id == b.b_id)

Then, c.show() yields:

+----+-----+-----+----+
|a_id|extra|other|b_id|
+----+-----+-----+----+
|   a|  foo|   p1|   a|
|   b|  hem|   p2|   b|
|   c|  haw|   p3|   c|
+----+-----+-----+----+

How can I get the current date and time in UTC or GMT in Java?

To put it simple. A calendar object stores information about time zone but when you perform cal.getTime() then the timezone information will be lost. So for Timezone conversions I will advice to use DateFormat classes...

count files in specific folder and display the number into 1 cel

Try below code :

Assign the path of the folder to variable FolderPath before running the below code.

Sub sample()

    Dim FolderPath As String, path As String, count As Integer
    FolderPath = "C:\Documents and Settings\Santosh\Desktop"

    path = FolderPath & "\*.xls"

    Filename = Dir(path)

    Do While Filename <> ""
       count = count + 1
        Filename = Dir()
    Loop

    Range("Q8").Value = count
    'MsgBox count & " : files found in folder"
End Sub

Running Google Maps v2 on the Android emulator

I have successfully run our app, which requires Google Maps API 2, on an AndroVM virtual machine.

AndroVM does not come with Google Maps or Google Play installed, but provides a modified copy of the Cyanogen Gapps archive, which is a set of the proprietary Google apps installed on most Android devices.

The instructions, copied from the AndroVM FAQ:

How can I install Google Apps (including the Market/Play app) ?

  • Download Google Apps : gapps-jb-20121011-androvm.tgz [basically the /system directory from the Cyanogen gapps archive without the GoogleTTS app which crashes on AndroVM]
  • Untar the gapps…tgz file on your host – you’ll have a system directory created
  • Get the management IP address of your AndroVM (“AndroVM Configuration” tool) and do “adb connect x.y.z.t”
  • do “adb root”
  • reconnect with “adn connect x.y.z.t”
  • do “adb remount”
  • do “adb push system/ /system/”

Your VM will reboot and you should have google apps including Market/Play.

You won’t have some Google Apps, like Maps, but they can be downloaded from the Market/Play.

So follow those instructions, then just install Google Maps using Google Play!

Some great side effects of using a VM rather than the emulator:

  • Vastly superior general performance
  • OpenGL acceleration
  • Google Play support

The only bump in the road so far has been lack of multi-touch gestures, which is a bummer for a mapping app! I plan to work around this with a hidden UI mechanism, so not such a huge problem.

Disable automatic sorting on the first column when using jQuery DataTables

If any of other solution doesn't fix it, try to override the styles to hide the sort togglers:

.sorting_asc:after, .sorting_desc:after {
  content: "";
}

How to write a cron that will run a script every day at midnight?

You can execute shell script in two ways,either by using cron job or by writing a shell script

Lets assume your script name is "yourscript.sh"

First check the user permission of the script. use below command to check user permission of the script

ll script.sh

If the script is in root,then use below command

sudo crontab -e

Second if the script holds the user "ubuntu", then use below command

crontab -e

Add the following line in your crontab:-

55 23 * * * /path/to/yourscript.sh

Another way of doing this is to write a script and run it in the backgroud

Here is the script where you have to put your script name(eg:- youscript.sh) which is going to run at 23:55pm everyday

#!/bin/bash while true do /home/modassir/yourscript.sh sleep 1d done

save it in a file (lets name it "every-day.sh")

sleep 1d - means it waits for one day and then it runs again.

now give the permission to your script.use below command:-

chmod +x every-day.sh

now, execute this shell script in the background by using "nohup". This will keep executing the script even after you logout from your session.

use below command to execute the script.

nohup ./every-day.sh &

Note:- to run "yourscript.sh" at 23:55pm everyday,you have to execute "every-day.sh" script at exactly 23:55pm.

How to set Spinner Default by its Value instead of Position?

If you are setting the spinner values by arraylist or array you can set the spinner's selection by using the index of the value.

String myString = "some value"; //the value you want the position for

ArrayAdapter myAdap = (ArrayAdapter) mySpinner.getAdapter(); //cast to an ArrayAdapter

int spinnerPosition = myAdap.getPosition(myString);

//set the default according to value
spinner.setSelection(spinnerPosition);

see the link How to set selected item of Spinner by value, not by position?

Get filename and path from URI from mediastore

Simple and easy. You can do this from the URI just like below!

public void getContents(Uri uri)
{
    Cursor vidCursor = getActivity.getContentResolver().query(uri, null, null,
                                                              null, null);
    if (vidCursor.moveToFirst())
    {
        int column_index =
        vidCursor .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        Uri filePathUri = Uri.parse(vidCursor .getString(column_index));
        String video_name =  filePathUri.getLastPathSegment().toString();
        String file_path=filePathUri.getPath();
        Log.i("TAG", video_name + "\b" file_path);
    }
}

AngularJS - convert dates in controller

item.date = $filter('date')(item.date, "dd/MM/yyyy"); // for conversion to string

http://docs.angularjs.org/api/ng.filter:date

But if you are using HTML5 type="date" then the ISO format yyyy-MM-dd MUST be used.

item.dateAsString = $filter('date')(item.date, "yyyy-MM-dd");  // for type="date" binding


<input type="date" ng-model="item.dateAsString" value="{{ item.dateAsString }}" pattern="dd/MM/YYYY"/>

http://www.w3.org/TR/html-markup/input.date.html

NOTE: use of pattern="" with type="date" looks non-standard, but it appears to work in the expected way in Chrome 31.

How to check for valid email address?

For check of email use email_validator

from email_validator import validate_email, EmailNotValidError

def check_email(email):
    try:
        v = validate_email(email)  # validate and get info
        email = v["email"]  # replace with normalized form
        print("True")
    except EmailNotValidError as e:
        # email is not valid, exception message is human-readable
        print(str(e))

check_email("test@gmailcom")

How could I create a list in c++?

Create list using C++ templates

i.e

template <class T> struct Node 
{
    T data;
    Node * next;
};
    
template <class T> class List 
{
    Node<T> *head,*tail;
        
    public: 
        void push(T const&);  // push element 
        void pop();           // pop element 
        bool empty()          // return true if empty. 
}; 

Then you can write the code like:

List<MyClass>;

The type T is not dynamic in run time.It is only for the compile time.

For complete example click here.

For C++ templates tutorial click here.

convert float into varchar in SQL server without scientific notation

Try this:

SELECT REPLACE(RTRIM(REPLACE(REPLACE(RTRIM(REPLACE(CAST(CAST(YOUR_FLOAT_COLUMN_NAME AS DECIMAL(18,9)) AS VARCHAR(20)),'0',' ')),' ','0'),'.',' ')),' ','.') FROM YOUR_TABLE_NAME
  1. Casting as DECIMAL will put decimal point on every value, whether it had one before or not.
  2. Casting as VARCHAR allows you to use the REPLACE function
  3. First REPLACE zeros with spaces, then RTRIM to get rid of all trailing spaces (formerly zeros), then REPLACE remaining spaces with zeros.
  4. Then do the same for the period to get rid of it for numbers with no decimal values.

How to make a div have a fixed size?

Try the following css:

#innerbox
{
   width:250px; /* or whatever width you want. */
   max-width:250px; /* or whatever width you want. */
   display: inline-block;
}

This makes the div take as little space as possible, and its width is defined by the css.

// Expanded answer

To make the buttons fixed widths do the following :

#innerbox input
{
   width:150px; /* or whatever width you want. */
   max-width:150px; /* or whatever width you want. */
}

However, you should be aware that as the size of the text changes, so does the space needed to display it. As such, it's natural that the containers need to expand. You should perhaps review what you are trying to do; and maybe have some predefined classes that you alter on the fly using javascript to ensure the content placement is perfect.

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException Error

Near the top of the code with the Public Workshop(), I am assumeing this bit,

suitButton = new JCheckBox("Suit");
suitButton.setMnemonic(KeyEvent.VK_Y);


suitButton = new JCheckBox("Denim Jeans");
suitButton.setMnemonic(KeyEvent.VK_U);

should maybe be,

suitButton = new JCheckBox("Suit");
suitButton.setMnemonic(KeyEvent.VK_Y);


denimjeansButton = new JCheckBox("Denim Jeans");
denimjeansButton.setMnemonic(KeyEvent.VK_U);

Export MySQL database using PHP only

I would Suggest that you do the folllowing,

<?php

function EXPORT_TABLES($host, $user, $pass, $name, $tables = false, $backup_name = false)
{
    $mysqli      = new mysqli($host, $user, $pass, $name);
    $mysqli->select_db($name);
    $mysqli->query("SET NAMES 'utf8'");
    $queryTables = $mysqli->query('SHOW TABLES');
    while ($row         = $queryTables->fetch_row())
    {
        $target_tables[] = $row[0];
    }
    if ($tables !== false)
    {
        $target_tables = array_intersect($target_tables, $tables);
    }
    $content = "SET SQL_MODE = \"NO_AUTO_VALUE_ON_ZERO\";\r\nSET time_zone = \"+00:00\";\r\n\r\n\r\n/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;\r\n/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;\r\n/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;\r\n/*!40101 SET NAMES utf8 */;\r\n--Database: `" . $name . "`\r\n\r\n\r\n";
    foreach ($target_tables as $table)
    {
        $result        = $mysqli->query('SELECT * FROM ' . $table);
        $fields_amount = $result->field_count;
        $rows_num      = $mysqli->affected_rows;
        $res           = $mysqli->query('SHOW CREATE TABLE ' . $table);
        $TableMLine    = $res->fetch_row();
        $content .= "\n\n" . $TableMLine[1] . ";\n\n";
        for ($i = 0, $st_counter = 0; $i < $fields_amount; $i++, $st_counter = 0)
        {
            while ($row = $result->fetch_row())
            { //when started (and every after 100 command cycle):
                if ($st_counter % 100 == 0 || $st_counter == 0)
                {
                    $content .= "\nINSERT INTO " . $table . " VALUES";
                }
                $content .= "\n(";
                for ($j = 0; $j < $fields_amount; $j++)
                {
                    $row[$j] = str_replace("\n", "\\n", addslashes($row[$j]));
                    if (isset($row[$j]))
                    {
                        $content .= '"' . $row[$j] . '"';
                    }
                    else
                    {
                        $content .= '""';
                    } if ($j < ($fields_amount - 1))
                    {
                        $content.= ',';
                    }
                }
                $content .=")";
                //every after 100 command cycle [or at last line] ....p.s. but should be inserted 1 cycle eariler
                if ((($st_counter + 1) % 100 == 0 && $st_counter != 0) || $st_counter + 1 == $rows_num)
                {
                    $content .= ";";
                }
                else
                {
                    $content .= ",";
                } $st_counter = $st_counter + 1;
            }
        } $content .="\n\n\n";
    }
    $content .= "\r\n\r\n/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;\r\n/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;\r\n/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;";
    $backup_name = $backup_name ? $backup_name : $name . "___(" . date('H-i-s') . "_" . date('d-m-Y') . ")__rand" . rand(1, 11111111) . ".sql";
    header('Content-Type: application/octet-stream');
    header("Content-Transfer-Encoding: Binary");
    header("Content-disposition: attachment; filename=\"" . $backup_name . "\"");
    echo $content;
    exit;
}
?>

The enitre project for export and import can be found at https://github.com/tazotodua/useful-php-scripts.

Starting the week on Monday with isoWeekday()

try using begin.startOf('isoWeek'); instead of begin.startOf('week');

Using IQueryable with Linq

Marc Gravell's answer is very complete, but I thought I'd add something about this from the user's point of view, as well...


The main difference, from a user's perspective, is that, when you use IQueryable<T> (with a provider that supports things correctly), you can save a lot of resources.

For example, if you're working against a remote database, with many ORM systems, you have the option of fetching data from a table in two ways, one which returns IEnumerable<T>, and one which returns an IQueryable<T>. Say, for example, you have a Products table, and you want to get all of the products whose cost is >$25.

If you do:

 IEnumerable<Product> products = myORM.GetProducts();
 var productsOver25 = products.Where(p => p.Cost >= 25.00);

What happens here, is the database loads all of the products, and passes them across the wire to your program. Your program then filters the data. In essence, the database does a SELECT * FROM Products, and returns EVERY product to you.

With the right IQueryable<T> provider, on the other hand, you can do:

 IQueryable<Product> products = myORM.GetQueryableProducts();
 var productsOver25 = products.Where(p => p.Cost >= 25.00);

The code looks the same, but the difference here is that the SQL executed will be SELECT * FROM Products WHERE Cost >= 25.

From your POV as a developer, this looks the same. However, from a performance standpoint, you may only return 2 records across the network instead of 20,000....

powershell mouse move does not prevent idle mode

Try this: (source: http://just-another-blog.net/programming/powershell-and-the-net-framework/)

Add-Type -AssemblyName System.Windows.Forms 

$position = [System.Windows.Forms.Cursor]::Position  
$position.X++  
[System.Windows.Forms.Cursor]::Position = $position 

    while(1) {  
    $position = [System.Windows.Forms.Cursor]::Position  
    $position.X++  
    [System.Windows.Forms.Cursor]::Position = $position  

    $time = Get-Date;  
    $shorterTimeString = $time.ToString("HH:mm:ss");  

    Write-Host $shorterTimeString "Mouse pointer has been moved 1 pixel to the right"  
    #Set your duration between each mouse move
    Start-Sleep -Seconds 150  
    }  

Capturing "Delete" Keypress with jQuery

$('html').keyup(function(e){
    if(e.keyCode == 46) {
        alert('Delete key released');
    }
});

Source: javascript char codes key codes from www.cambiaresearch.com

Detecting attribute change of value of an attribute I made

There is this extensions that adds an event listener to attribute changes.

Usage:

<script type="text/javascript" src="http://code.jquery.com/jquery.min.js"></script>
<script type="text/javascript"
  src="https://cdn.rawgit.com/meetselva/attrchange/master/js/attrchange.js"></script>

Bind attrchange handler function to selected elements

$(selector).attrchange({
    trackValues: true, /* Default to false, if set to true the event object is 
                updated with old and new value.*/
    callback: function (event) { 
        //event               - event object
        //event.attributeName - Name of the attribute modified
        //event.oldValue      - Previous value of the modified attribute
        //event.newValue      - New value of the modified attribute
        //Triggered when the selected elements attribute is added/updated/removed
    }        
});

How to merge many PDF files into a single one?

There are lots of free tools that can do this.

I use PDFTK (a open source cross-platform command-line tool) for things like that.

Value Change Listener to JTextField

If we use runnable method SwingUtilities.invokeLater() while using Document listener application is getting stuck sometimes and taking time to update the result(As per my experiment). Instead of that we can also use KeyReleased event for text field change listener as mentioned here.

usernameTextField.addKeyListener(new KeyAdapter() {
    public void keyReleased(KeyEvent e) {
        JTextField textField = (JTextField) e.getSource();
        String text = textField.getText();
        textField.setText(text.toUpperCase());
    }
});

Differences between Octave and MATLAB?

MATLAB is, first and foremost, a commercial offering. Therefore, everything in MATLAB pretty much works out of the box. All the core functionality is solid, and if you're working on a special project then MATLAB probably has an add-on they can sell you that adds a lot of additional domain-specific .m files for you. It ain't cheap, but it works and it will get the job done without complaint.

Octave always shows its open-source, information-wants-to-be-free roots. It's free, and it will remind you that it's free at every opportunity. It's developed by volunteers who hate Windows with a passion. Therefore Octave runs on Windows grudgingly. It's quite surprising that as many MATLAB features exist as they do.

But here's the rub. Anytime you try to do something more than trivially complex, Octave suddenly breaks in subtle and hard to understand ways. Oops -- the terminal driver had an overflow somewhere deep in the OpenGL layer. You can't print. Oops -- the figure plots do strange things with their fonts. Good luck figuring out why. Oops -- there's some hidden dependency between Octave and some other obscure bit of free software, so it won't compile. Good luck figuring out which it is.

And the Octave response is hey! It's free software! You have all the source code, you can fix all those bugs yourself! Maybe if I had infinite time and resources on my hands, I could spend all my time fixing bugs in free software, but I personally don't. If I worked in academia, I might.

So at the core, the issue of whether to choose MATLAB or Octave comes down to one question. Interestingly, that question is always the same, when choosing between commercial vs. free software variants.

And the question is:

Do you have more money than time?

Use of "this" keyword in C++

Yes. unless, there is an ambiguity.

Location of my.cnf file on macOS

I don't know which version of MySQL you're using, but here are possible locations of the my.cnf file for version 5.5 (taken from here) on Mac OS X:

  1. /etc/my.cnf
  2. /etc/mysql/my.cnf
  3. SYSCONFDIR/my.cnf
  4. $MYSQL_HOME/my.cnf
  5. defaults-extra-file (the file specified with --defaults-extra-file=path, if any)
  6. ~/.my.cnf

How do I show the number keyboard on an EditText in android?

editText.setRawInputType(InputType.TYPE_CLASS_NUMBER);

HTML input field hint

Define tooltip text

<input type="text" id="firstname" name="firstname" tooltipText="Type in your firstname in this box"> 

Initialize and configure the script

<script type="text/javascript">
var tooltipObj = new DHTMLgoodies_formTooltip();
tooltipObj.setTooltipPosition('right');
tooltipObj.setPageBgColor('#EEE');
tooltipObj.setCloseMessage('Exit');
tooltipObj.initFormFieldTooltip();
</script> 

Program to find prime numbers

so this is basically just two typos, one, the most unfortunate, for (int j = 2; j <= num; j++) which is the reason for the unproductive testing of 1%2,1%3 ... 1%(10^15-1) which goes on for very long time so the OP didn't get "any output". It should've been j < i; instead. The other, minor one in comparison, is that i should start from 2, not from 0:

for( i=2; i <= num; i++ )
{
    for( j=2; j < i; j++ ) // j <= sqrt(i) is really enough
....

Surely it can't be reasonably expected of a console print-out of 28 trillion primes or so to be completed in any reasonable time-frame. So, the original intent of the problem was obviously to print out a steady stream of primes, indefinitely. Hence all the solutions proposing simple use of sieve of Eratosthenes are totally without merit here, because simple sieve of Eratosthenes is bounded - a limit must be set in advance.

What could work here is the optimized trial division which would save the primes as it finds them, and test against the primes, not just all numbers below the candidate.

Second alternative, with much better complexity (i.e. much faster) is to use a segmented sieve of Eratosthenes. Which is incremental and unbounded.

Both these schemes would use double-staged production of primes: one would produce and save the primes, to be used by the other stage in testing (or sieving), much above the limit of the first stage (below its square of course - automatically extending the first stage, as the second stage would go further and further up).

How do I remove a comma off the end of a string?

rtrim ($string , ","); is the easiest way.

How to initialize a list of strings (List<string>) with many string values

List<string> mylist = new List<string>(new string[] { "element1", "element2", "element3" });

Set keyboard caret position in html textbox

I found an easy way to fix this issue, tested in IE and Chrome:

function setCaret(elemId, caret)
 {
   var elem = document.getElementById(elemId);
   elem.setSelectionRange(caret, caret);
 }

Pass text box id and caret position to this function.

What is the size of an enum in C?

Taken from the current C Standard (C99): http://www.open-std.org/JTC1/SC22/WG14/www/docs/n1256.pdf

6.7.2.2 Enumeration specifiers
[...]
Constraints
The expression that defines the value of an enumeration constant shall be an integer constant expression that has a value representable as an int.
[...]
Each enumerated type shall be compatible with char, a signed integer type, or an unsigned integer type. The choice of type is implementation-defined, but shall be capable of representing the values of all the members of the enumeration.

Not that compilers are any good at following the standard, but essentially: If your enum holds anything else than an int, you're in deep "unsupported behavior that may come back biting you in a year or two" territory.

Update: The latest publicly available draft of the C Standard (C11): http://www.open-std.org/JTC1/SC22/WG14/www/docs/n1570.pdf contains the same clauses. Hence, this answer still holds for C11.

MySQL - UPDATE multiple rows with different values in one query

MySQL allows a more readable way to combine multiple updates into a single query. This seems to better fit the scenario you describe, is much easier to read, and avoids those difficult-to-untangle multiple conditions.

INSERT INTO table_users (cod_user, date, user_rol, cod_office)
VALUES
('622057', '12082014', 'student', '17389551'),
('2913659', '12082014', 'assistant','17389551'),
('6160230', '12082014', 'admin', '17389551')
ON DUPLICATE KEY UPDATE
 cod_user=VALUES(cod_user), date=VALUES(date)

This assumes that the user_rol, cod_office combination is a primary key. If only one of these is the primary key, then add the other field to the UPDATE list. If neither of them is a primary key (that seems unlikely) then this approach will always create new records - probably not what is wanted.

However, this approach makes prepared statements easier to build and more concise.

How to implement a ViewPager with different Fragments / Layouts

Create an array of Views and apply it to: container.addView(viewarr[position]);

public class Layoutes extends PagerAdapter {

    private Context context;
    private LayoutInflater layoutInflater;
    Layoutes(Context context){
        this.context=context;
    }
    int layoutes[]={R.layout.one,R.layout.two,R.layout.three};
    @Override
    public int getCount() {
        return layoutes.length;
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return (view==(LinearLayout)object);
    }
    @Override
    public Object instantiateItem(ViewGroup container, int position){
        layoutInflater=(LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View one=layoutInflater.inflate(R.layout.one,container,false);
        View two=layoutInflater.inflate(R.layout.two,container,false);
        View three=layoutInflater.inflate(R.layout.three,container,false);
        View viewarr[]={one,two,three};
        container.addView(viewarr[position]);
        return viewarr[position];
    }
    @Override
    public void destroyItem(ViewGroup container, int position, Object object){
        container.removeView((LinearLayout) object);
    }

}

React PropTypes : Allow different types of PropTypes for one prop

import React from 'react';              <--as normal
import PropTypes from 'prop-types';     <--add this as a second line

    App.propTypes = {
        monkey: PropTypes.string,           <--omit "React."
        cat: PropTypes.number.isRequired    <--omit "React."
    };

    Wrong:  React.PropTypes.string
    Right:  PropTypes.string

Spring Security with roles and permissions

ACL was overkill for my requirements also.
I ended up creating a library similar to @Alexander's to inject a GrantedAuthority list for Role->Permissions based on the role membership of a user.

For example, using a DB to hold the relationships -

@Autowired 
RolePermissionsRepository repository;

public void setup(){
  String roleName = "ROLE_ADMIN";
  List<String> permissions = new ArrayList<String>();
  permissions.add("CREATE");
  permissions.add("READ");
  permissions.add("UPDATE");
  permissions.add("DELETE");
  repository.save(new RolePermissions(roleName, permissions));
}

When an Authentication object is injected in the current security session, it will have the original roles/granted authorities.

This library provides 2 built-in integration points for Spring Security. When the integration point is reached, the PermissionProvider is called to get the effective permissions for each role the user is a member of.
The distinct list of permissions are added as GrantedAuthority items in the Authentication object.

You can also implement a custom PermissionProvider to store the relationships in config for example.

A more complete explanation here - https://stackoverflow.com/a/60251931/1308685

And the source code is here - https://github.com/savantly-net/spring-role-permissions