SyntaxFix

Programs & Examples On #Replicate

Create sequence of repeated values, in sequence?

Another base R option could be gl():

gl(5, 3)

Where the output is a factor:

 [1] 1 1 1 2 2 2 3 3 3 4 4 4 5 5 5
Levels: 1 2 3 4 5

If integers are needed, you can convert it:

as.numeric(gl(5, 3))

 [1] 1 1 1 2 2 2 3 3 3 4 4 4 5 5 5

Repeat each row of data.frame the number of times specified in a column

Here's one solution:

df.expanded <- df[rep(row.names(df), df$freq), 1:2]

Result:

    var1 var2
1      a    d
2      b    e
2.1    b    e
3      c    f
3.1    c    f
3.2    c    f

Create list of single item repeated N times

As others have pointed out, using the * operator for a mutable object duplicates references, so if you change one you change them all. If you want to create independent instances of a mutable object, your xrange syntax is the most Pythonic way to do this. If you are bothered by having a named variable that is never used, you can use the anonymous underscore variable.

[e for _ in xrange(n)]

Replace or delete certain characters from filenames of all files in a folder

The PowerShell answers are good, but the Rename-Item command doesn't work in the same target directory unless ALL of your files have the unwanted character in them (fails if it finds duplicates).

If you're like me and had a mix of good names and bad names, try this script instead (will replace spaces with an underscore):

Get-ChildItem -recurse -name | ForEach-Object { Move-Item $_ $_.replace(" ", "_") }

pandas dataframe groupby datetime month

Slightly alternative solution to @jpp's but outputting a YearMonth string:

df['YearMonth'] = pd.to_datetime(df['Date']).apply(lambda x: '{year}-{month}'.format(year=x.year, month=x.month))

res = df.groupby('YearMonth')['Values'].sum()

How to use '-prune' option of 'find' in sh?

I am no expert at this (and this page was very helpful along with http://mywiki.wooledge.org/UsingFind)

Just noticed -path is for a path that fully matches the string/path that comes just after find (. in theses examples) where as -name matches all basenames.

find . -path ./.git  -prune -o -name file  -print

blocks the .git directory in your current directory ( as your finding in . )

find . -name .git  -prune -o -name file  -print

blocks all .git subdirectories recursively.

Note the ./ is extremely important!! -path must match a path anchored to . or whatever comes just after find if you get matches with out it (from the other side of the or '-o') there probably not being pruned! I was naively unaware of this and it put me of using -path when it is great when you don't want to prune all subdirectory with the same basename :D

How to write a link like <a href="#id"> which link to the same page in PHP?

try this

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html>
    <body>
        <a href="#name">click me</a>
<br><br><br><br><br><br><br><br><br><br><br>
<br><br><br><br><br><br><br><br><br><br><br>
<br><br><br><br><br><br><br><br><br><br><br>
        <div name="name" id="name">here</div>
    </body>
    </html>

how to upload a file to my server using html

 
<form id="uploadbanner" enctype="multipart/form-data" method="post" action="#">
   <input id="fileupload" name="myfile" type="file" />
   <input type="submit" value="submit" id="submit" />
</form>

To upload a file, it is essential to set enctype="multipart/form-data" on your form

You need that form type and then some php to process the file :)

You should probably check out Uploadify if you want something very customisable out of the box.

How to break lines in PowerShell?

Try "`n" with double quotes. (not single quotes '`n' )

For a complete list of escaping characters see:

Help about_Escape_character

The code should be

$str += "`n"

How to define custom configuration variables in rails

In Rails 3.0.5, the following approach worked for me:

In config/environments/development.rb, write

config.custom_config_key = :config_value

The value custom_config_key can then be referenced from other files using

Rails.application.config.custom_config_key

How to use onClick event on react Link component?

You should use this:

<Link to={this.props.myroute} onClick={hello}>Here</Link>

Or (if method hello lays at this class):

<Link to={this.props.myroute} onClick={this.hello}>Here</Link>

Update: For ES6 and latest if you want to bind some param with click method, you can use this:

    const someValue = 'some';  
....  
    <Link to={this.props.myroute} onClick={() => hello(someValue)}>Here</Link>

Best way to copy a database (SQL Server 2008)

Below is what I do to copy a database from production env to my local env:

  1. Create an empty database in your local sql server
  2. Right click on the new database -> tasks -> import data
  3. In the SQL Server Import and Export Wizard, select product env's servername as data source. And select your new database as the destination data.

Where are static methods and static variables stored in Java?

Prior to Java 8:

The static variables were stored in the permgen space(also called the method area).

PermGen Space is also known as Method Area

PermGen Space used to store 3 things

  1. Class level data (meta-data)
  2. interned strings
  3. static variables

From Java 8 onwards

The static variables are stored in the Heap itself.From Java 8 onwards the PermGen Space have been removed and new space named as MetaSpace is introduced which is not the part of Heap any more unlike the previous Permgen Space. Meta-Space is present on the native memory (memory provided by the OS to a particular Application for its own usage) and it now only stores the class meta-data.

The interned strings and static variables are moved into the heap itself.

For official information refer : JEP 122:Remove the Permanent Gen Space

jQuery autoComplete view all on click?

 
<input type="text" name="q" id="q" placeholder="Selecciona..."/>


<script type="text/javascript">
//Mostrar el autocompletado con el evento focus
//Duda o comentario: http://WilzonMB.com
$(function () {
    var availableTags = [
        "MongoDB",
        "ExpressJS",
        "Angular",
        "NodeJS",
        "JavaScript",                
        "jQuery",
        "jQuery UI",
        "PHP",
        "Zend Framework",
        "JSON",
        "MySQL",
        "PostgreSQL",
        "SQL Server",
        "Oracle",
        "Informix",
        "Java",
        "Visual basic",
        "Yii",
        "Technology",
        "WilzonMB.com"
    ];
    $("#q").autocomplete({
        source: availableTags,
        minLength: 0
    }).focus(function(){            
       $(this).autocomplete('search', $(this).val())
     });
});
</script>

http://jsfiddle.net/wimarbueno/6zz8euqe/

ImportError: No module named _ssl

I am writing this solution for those who are still facing such issue and cant find the solution.

in my case, I am using

shared hosting (Cpanel Access) Linux CentOS.

I was facing this issue

No module named '_ssl'

I tried for all possible solutions but as you know sometimes things don't work for you and in hosting you don't have access to fully root and run queries. even my hosting provider did for me.. but NO GOOD RESULT.

so how I solved if you are using shared hosting and you have deployed your Django App using

Setup Python App

You only have to downgrade your Python Version, I downgraded from

Python 3.7.3

(As Python 3.7 does not have SSL module in it) To

Python 3.6.8

through Setup Python App.

Hope it will be helpful for someone with the same issue,

How do we control web page caching, across all browsers?

I've had best and most consistent results across all browsers by setting Pragma: no-cache

How do you kill a Thread in Java?

The question is rather vague. If you meant “how do I write a program so that a thread stops running when I want it to”, then various other responses should be helpful. But if you meant “I have an emergency with a server I cannot restart right now and I just need a particular thread to die, come what may”, then you need an intervention tool to match monitoring tools like jstack.

For this purpose I created jkillthread. See its instructions for usage.

How to check object is nil or not in swift?

Swift 4 You cannot compare Any to nil.Because an optional can be nil and hence it always succeeds to true. The only way is to cast it to your desired object and compare it to nil.

if (someone as? String) != nil
{
   //your code`enter code here`
}

Excel Formula to SUMIF date falls in particular month

 
=SUMPRODUCT( (MONTH($A$2:$A$6)=1) * ($B$2:$B$6) )

Explanation:

  • (MONTH($A$2:$A$6)=1) creates an array of 1 and 0, it's 1 when the month is january, thus in your example the returned array would be [1, 1, 1, 0, 0]

  • SUMPRODUCT first multiplies each value of the array created in the above step with values of the array ($B$2:$B$6), then it sums them. Hence in your example it does this: (1 * 430) + (1 * 96) + (1 * 440) + (0 * 72.10) + (0 * 72.30)

This works also in OpenOffice and Google Spreadsheets

How to check if a string is null in python

Try this:

if cookie and not cookie.isspace():
    # the string is non-empty
else:
    # the string is empty

The above takes in consideration the cases where the string is None or a sequence of white spaces.

Make a link use POST instead of GET

HTML + JQuery: A link that submits a hidden form with POST.

Since I spent a lot of time to understand all these answers, and since all of them have some interesting details, here is the combined version that finally worked for me and which I prefer for its simplicity.

My approach is again to create a hidden form and to submit it by clicking a link somewhere else in the page. It doesn't matter where in the body of the page the form will be placed.

The code for the form:

<form id="myHiddenFormId" action="myAction.php" method="post" style="display: none">
  <input type="hidden" name="myParameterName" value="myParameterValue">
</form>

Description:

The display: none hides the form. You can alternatively put it in a div or another element and set the display: none on the element.

The type="hidden" will create an fild that will not be shown but its data will be transmitted to the action eitherways (see W3C). I understand that this is the simplest input type.

The code for the link:

<a href="" onclick="$('#myHiddenFormId').submit(); return false;" title="My link title">My link text</a>

Description:

The empty href just targets the same page. But it doesn't really matter in this case since the return false will stop the browser from following the link. You may want to change this behavior of course. In my specific case, the action contained a redirection at the end.

The onclick was used to avoid using href="javascript:..." as noted by mplungjan. The $('#myHiddenFormId').submit(); was used to submit the form (instead of defining a function, since the code is very small).

This link will look exactly like any other <a> element. You can actually use any other element instead of the <a> (for example a <span> or an image).

How to insert a line break before an element using CSS

assuming you want the line height to be 20 px

  .restart:before { 
     content: 'First Line';
     padding-bottom:20px;
  }
  .restart:after { 
    content: 'Second-line';
    position:absolute;
    top:40px;
  }

How do I remove documents using Node.js Mongoose?

If you don't feel like iterating, try FBFriendModel.find({ id:333 }).remove( callback ); or FBFriendModel.find({ id:333 }).remove().exec();

mongoose.model.find returns a Query, which has a remove function.

Update for Mongoose v5.5.3 - remove() is now deprecated. Use deleteOne(), deleteMany() or findOneAndDelete() instead.

Find where python is installed (if it isn't default dir)

Have a look at sys.path:

>>> import sys
>>> print(sys.path)

Creating an index on a table variable

It should be understood that from a performance standpoint there are no differences between @temp tables and #temp tables that favor variables. They reside in the same place (tempdb) and are implemented the same way. All the differences appear in additional features. See this amazingly complete writeup: https://dba.stackexchange.com/questions/16385/whats-the-difference-between-a-temp-table-and-table-variable-in-sql-server/16386#16386

Although there are cases where a temp table can't be used such as in table or scalar functions, for most other cases prior to v2016 (where even filtered indexes can be added to a table variable) you can simply use a #temp table.

The drawback to using named indexes (or constraints) in tempdb is that the names can then clash. Not just theoretically with other procedures but often quite easily with other instances of the procedure itself which would try to put the same index on its copy of the #temp table.

To avoid name clashes, something like this usually works:

declare @cmd varchar(500)='CREATE NONCLUSTERED INDEX [ix_temp'+cast(newid() as varchar(40))+'] ON #temp (NonUniqueIndexNeeded);';
exec (@cmd);

This insures the name is always unique even between simultaneous executions of the same procedure.

Sending and Receiving SMS and MMS in Android (pre Kit Kat Android 4.4)

There is not official api support which means that it is not documented for the public and the libraries may change at any time. I realize you don't want to leave the application but here's how you do it with an intent for anyone else wondering.

public void sendData(int num){
    String fileString = "..."; //put the location of the file here
    Intent mmsIntent = new Intent(Intent.ACTION_SEND);
    mmsIntent.putExtra("sms_body", "text");
    mmsIntent.putExtra("address", num);
    mmsIntent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(new File(fileString)));
    mmsIntent.setType("image/jpeg");
    startActivity(Intent.createChooser(mmsIntent, "Send"));

}

I haven't completely figured out how to do things like track the delivery of the message but this should get it sent.

You can be alerted to the receipt of mms the same way as sms. The intent filter on the receiver should look like this.

<intent-filter>
    <action android:name="android.provider.Telephony.WAP_PUSH_RECEIVED" />
    <data android:mimeType="application/vnd.wap.mms-message" />
</intent-filter>

jQuery to remove an option from drop down list, given option's text/value

First find the class name for particular select. 

$('#id').val('');
$('#selectoptionclassname').selectpicker('refresh');

getting error HTTP Status 405 - HTTP method GET is not supported by this URL but not used `get` ever?

The problem is that you mapped your servlet to /register.html and it expects POST method, because you implemented only doPost() method. So when you open register.html page, it will not open html page with the form but servlet that handles the form data.

Alternatively when you submit POST form to non-existing URL, web container will display 405 error (method not allowed) instead of 404 (not found).

To fix:

<servlet-mapping>
    <servlet-name>Register</servlet-name>
    <url-pattern>/Register</url-pattern>
</servlet-mapping>

How can I check the system version of Android?

use this class

import android.os.Build;

/**
 * Created by MOMANI on 2016/04/14.
 */
public class AndroidVersionUtil {
    public static int getApiVersion() {
        return android.os.Build.VERSION.SDK_INT;
    }

    public static boolean isApiVersionGraterOrEqual(int thisVersion) {
        return android.os.Build.VERSION.SDK_INT >= thisVersion;
    }
}

Issue in installing php7.2-mcrypt

As an alternative, you can install 7.1 version of mcrypt and create a symbolic link to it:

Install php7.1-mcrypt:

sudo apt install php7.1-mcrypt

Create a symbolic link:

sudo ln -s /etc/php/7.1/mods-available/mcrypt.ini /etc/php/7.2/mods-available

After enabling mcrypt by sudo phpenmod mcrypt, it gets available.

Uncaught TypeError: data.push is not a function

you can use push method only if the object is an array:

var data = new Array();
data.push({"country": "IN"}).

OR

data['country'] = "IN"

if it's just an object you can use

data.country = "IN";

How do I debug Node.js applications?

I wrote a different approach to debug Node.js code which is stable and is extremely simple. It is available at https://github.com/s-a/iron-node.

Enter image description here

An opensource cross-platform visual debugger.

Installation:

npm install iron-node -g;

Debug:

iron-node yourscript.js;

C# Validating input for textbox on winforms

With WinForms you can use the ErrorProvider in conjunction with the Validating event to handle the validation of user input. The Validating event provides the hook to perform the validation and ErrorProvider gives a nice consistent approach to providing the user with feedback on any error conditions.

http://msdn.microsoft.com/en-us/library/system.windows.forms.errorprovider.aspx

npm ERR! Error: EPERM: operation not permitted, rename

Just delete the package folder from the path of npm global packages. then reinstall the package. Note that the packages are globally installed in: C:\Users\your-name\AppData\Roaming\npm\node_modules

Substitute a comma with a line break in a cell

You can also do this without VBA from the find/replace dialogue box. My answer was at https://stackoverflow.com/a/6116681/509840 .

What is the canonical way to trim a string in Ruby without creating a new string?

If you are using Ruby on Rails there is a squish

> @title = " abc "
 => " abc " 

> @title.squish
 => "abc"
> @title
 => " abc "

> @title.squish!
 => "abc"
> @title
 => "abc"

If you are using just Ruby you want to use strip

Herein lies the gotcha.. in your case you want to use strip without the bang !

while strip! certainly does return nil if there was no action it still updates the variable so strip! cannot be used inline. If you want to use strip inline you can use the version without the bang !

strip! using multi line approach

> tokens["Title"] = " abc "
 => " abc "
> tokens["Title"].strip!
 => "abc"
> @title = tokens["Title"]
 => "abc"

strip single line approach... YOUR ANSWER

> tokens["Title"] = " abc "
 => " abc "
> @title = tokens["Title"].strip if tokens["Title"].present?
 => "abc"

Switching between GCC and Clang/LLVM using CMake

According to the help of cmake:

-C <initial-cache>
     Pre-load a script to populate the cache.

     When cmake is first run in an empty build tree, it creates a CMakeCache.txt file and populates it with customizable settings for the project.  This option may be used to specify a  file  from
     which to load cache entries before the first pass through the project's cmake listfiles.  The loaded entries take priority over the project's default values.  The given file should be a CMake
     script containing SET commands that use the CACHE option, not a cache-format file.

You make be able to create files like gcc_compiler.txt and clang_compiler.txt to includes all relative configuration in CMake syntax.

Clang Example (clang_compiler.txt):

 set(CMAKE_C_COMPILER "/usr/bin/clang" CACHE string "clang compiler" FORCE)

Then run it as

GCC:

cmake -C gcc_compiler.txt XXXXXXXX

Clang:

cmake -C clang_compiler.txt XXXXXXXX

Algorithm to detect overlapping periods

I'm building a booking system and found this page. I'm interested in range intersection only, so I built this structure; it is enough to play with DateTime ranges.

You can check Intersection and check if a specific date is in range, and get the intersection type and the most important: you can get intersected Range.

public struct DateTimeRange
{

    #region Construction
    public DateTimeRange(DateTime start, DateTime end) {
        if (start>end) {
            throw new Exception("Invalid range edges.");
        }
        _Start = start;
        _End = end;
    }
    #endregion

    #region Properties
    private DateTime _Start;

    public DateTime Start {
        get { return _Start; }
        private set { _Start = value; }
    }
    private DateTime _End;

    public DateTime End {
        get { return _End; }
        private set { _End = value; }
    }
    #endregion

    #region Operators
    public static bool operator ==(DateTimeRange range1, DateTimeRange range2) {
        return range1.Equals(range2);
    }

    public static bool operator !=(DateTimeRange range1, DateTimeRange range2) {
        return !(range1 == range2);
    }
    public override bool Equals(object obj) {
        if (obj is DateTimeRange) {
            var range1 = this;
            var range2 = (DateTimeRange)obj;
            return range1.Start == range2.Start && range1.End == range2.End;
        }
        return base.Equals(obj);
    }
    public override int GetHashCode() {
        return base.GetHashCode();
    }
    #endregion

    #region Querying
    public bool Intersects(DateTimeRange range) {
        var type = GetIntersectionType(range);
        return type != IntersectionType.None;
    }
    public bool IsInRange(DateTime date) {
        return (date >= this.Start) && (date <= this.End);
    }
    public IntersectionType GetIntersectionType(DateTimeRange range) {
        if (this == range) {
            return IntersectionType.RangesEqauled;
        }
        else if (IsInRange(range.Start) && IsInRange(range.End)) {
            return IntersectionType.ContainedInRange;
        }
        else if (IsInRange(range.Start)) {
            return IntersectionType.StartsInRange;
        }
        else if (IsInRange(range.End)) {
            return IntersectionType.EndsInRange;
        }
        else if (range.IsInRange(this.Start) && range.IsInRange(this.End)) {
            return IntersectionType.ContainsRange;
        }
        return IntersectionType.None;
    }
    public DateTimeRange GetIntersection(DateTimeRange range) {
        var type = this.GetIntersectionType(range);
        if (type == IntersectionType.RangesEqauled || type==IntersectionType.ContainedInRange) {
            return range;
        }
        else if (type == IntersectionType.StartsInRange) {
            return new DateTimeRange(range.Start, this.End);
        }
        else if (type == IntersectionType.EndsInRange) {
            return new DateTimeRange(this.Start, range.End);
        }
        else if (type == IntersectionType.ContainsRange) {
            return this;
        }
        else {
            return default(DateTimeRange);
        }
    }
    #endregion


    public override string ToString() {
        return Start.ToString() + " - " + End.ToString();
    }
}
public enum IntersectionType
{
    /// <summary>
    /// No Intersection
    /// </summary>
    None = -1,
    /// <summary>
    /// Given range ends inside the range
    /// </summary>
    EndsInRange,
    /// <summary>
    /// Given range starts inside the range
    /// </summary>
    StartsInRange,
    /// <summary>
    /// Both ranges are equaled
    /// </summary>
    RangesEqauled,
    /// <summary>
    /// Given range contained in the range
    /// </summary>
    ContainedInRange,
    /// <summary>
    /// Given range contains the range
    /// </summary>
    ContainsRange,
}

How to make Java Set?

Like this:

import java.util.*;
Set<Integer> a = new HashSet<Integer>();
a.add( 1);
a.add( 2);
a.add( 3);

Or adding from an Array/ or multiple literals; wrap to a list, first.

Integer[] array = new Integer[]{ 1, 4, 5};
Set<Integer> b = new HashSet<Integer>();
b.addAll( Arrays.asList( b));         // from an array variable
b.addAll( Arrays.asList( 8, 9, 10));  // from literals

To get the intersection:

// copies all from A;  then removes those not in B.
Set<Integer> r = new HashSet( a);
r.retainAll( b);
// and print;   r.toString() implied.
System.out.println("A intersect B="+r);

Hope this answer helps. Vote for it!

jQuery disable/enable submit button

The answers above don't address also checking for menu based cut/paste events. Below's the code that I use to do both. Note the action actually happens with a timeout because the cut and past events actually fire before the change happened, so timeout gives a little time for that to happen.

$( ".your-input-item" ).bind('keyup cut paste',function() {
    var ctl = $(this);
    setTimeout(function() {
        $('.your-submit-button').prop( 'disabled', $(ctl).val() == '');
    }, 100);
});

Run Function After Delay

I searched and found the solution in the following URL is better.

http://www.tutorialrepublic.com/faq/call-a-function-after-some-time-in-jquery.php

It worth to try.

It adds your given function to the queue of functions to be executed on the matched element which is currently this.

 $(this).delay(1000).queue(function() {

     // your Code | Function here
     
     $(this).dequeue();
  
  });

and then execute the next function on the queue for the matched element(s) which is currently this again.

-- EDIT [ POSSIBLE EXPLANATION FOR THE DEQUEUE COMMAND ]

Take a look at the command

We command the jQuery engine to add a function in internal queue and then after a specific amount of time we command it to call that function, BUT so far we never told it to dequeue it from engine. Right?! And then after every thing is done we are dequeue it from jQuery engine manually. I hope the explanation could help.

How to get the xml node value in string

 
XmlDocument d = new XmlDocument();
d.Load(@"D:\Work_Time_Calculator\10-07-2013.xml");
XmlNodeList n = d.GetElementsByTagName("Short_Fall");
if(n != null) {
    Console.WriteLine(n[0].InnerText); //Will output '08:29:57'
}

or you could wrap in foreach loop to print each value

XmlDocument d = new XmlDocument();
d.Load(@"D:\Work_Time_Calculator\10-07-2013.xml");
XmlNodeList n = d.GetElementsByTagName("Short_Fall");
if(n != null) {
    foreach(XmlNode curr in n) {
        Console.WriteLine(curr.InnerText);
    }
}

Cannot open output file, permission denied

The problem is that you don't have the administrator rights to access it as running or compilation of something is being done in the basic C drive. To eliminate this problem, run the devcpp.exe as an administrator. You could also change the permission from properties and allowing access read write modify etc for the system and by the system.

C++ IDE for Macs

If you are looking for a full-fledged IDE like Visual Studio, I think Eclipse might be your best bet.

Eclipse is also highly extensible and configurable.

See here: http://www.eclipse.org/downloads/

Convert UIImage to NSData and convert back to UIImage in Swift?

Use imageWithData: method, which gets translated to Swift as UIImage(data:)

let image : UIImage = UIImage(data: imageData)

Getting a list of files in a directory with a glob

Swift 5

This works for cocoa

        let bundleRoot = Bundle.main.bundlePath
        let manager = FileManager.default
        let dirEnum = manager.enumerator(atPath: bundleRoot)


        while let filename = dirEnum?.nextObject() as? String {
            if filename.hasSuffix(".data"){
                print("Files in resource folder: \(filename)")
            }
        }

ASP.net using a form to insert data into an sql server table

Simple, make a simple asp page with the designer (just for the beginning) Lets say the body is something like this:

<body>
    <form id="form1" runat="server">
    <div>
        <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
        <br />
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
    </div>
    <p>
        <asp:Button ID="Button1" runat="server" Text="Button" />
    </p>
    </form>
</body>

Great, now every asp object IS an object. So you can access it in the asp's CS code. The asp's CS code is triggered by events (mostly). The class will probably inherit from System.Web.UI.Page

If you go to the cs file of the asp page, you'll see a protected void Page_Load(object sender, EventArgs e) ... That's the load event, you can use that to populate data into your objects when the page loads.

Now, go to the button in your designer (Button1) and look at its properties, you can design it, or add events from there. Just change to the events view, and create a method for the event.

The button is a web control Button Add a Click event to the button call it Button1Click:

void Button1Click(Object sender,EventArgs e) { }

Now when you click the button, this method will be called. Because ASP is object oriented, you can think of the page as the actual class, and the objects will hold the actual current data.

So if for example you want to access the text in TextBox1 you just need to call that object in the C# code:

String firstBox = TextBox1.Text;

In the same way you can populate the objects when event occur.

Now that you have the data the user posted in the textboxes , you can use regular C# SQL connections to add the data to your database.

ORA-12514 TNS:listener does not currently know of service requested in connect descriptor

This error can occur when an application makes a new connection for every database interaction or the connections are not closed properly. One of the free tools to monitor and confirm this is Oracle Sql developer (although this is not the only tool you can use to monitor DB sessions).

you can download the tool from oracle site Sql Developer

here is a screenshot of how to monitor you sessions. (if you see many sessions piling up for your application user during when you see the ORA-12514 error then it's a good indication that you may have connection pool problem).

enter image description here

How to use a jQuery plugin inside Vue

run npm install jquery --save

then on your root component, place this

global.jQuery = require('../node_modules/jquery/dist/jquery.js');
var $ = global.jQuery;

Do not forget to export it to enable you to use it with other components

export default {
  name: 'App',
  components: {$}
}

Filter rows which contain a certain string

edit included the newer across() syntax

Here's another tidyverse solution, using filter(across()) or previously filter_at. The advantage is that you can easily extend to more than one column.

Below also a solution with filter_all in order to find the string in any column, using diamonds as example, looking for the string "V"

library(tidyverse)

String in only one column

# for only one column... extendable to more than one creating a column list in `across` or `vars`!
mtcars %>% 
  rownames_to_column("type") %>% 
  filter(across(type, ~ !grepl('Toyota|Mazda', .))) %>%
  head()
#>                type  mpg cyl  disp  hp drat    wt  qsec vs am gear carb
#> 1        Datsun 710 22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
#> 2    Hornet 4 Drive 21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
#> 3 Hornet Sportabout 18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
#> 4           Valiant 18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
#> 5        Duster 360 14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
#> 6         Merc 240D 24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2

The now superseded syntax for the same would be:

mtcars %>% 
  rownames_to_column("type") %>% 
  filter_at(.vars= vars(type), all_vars(!grepl('Toyota|Mazda',.)))

String in all columns:

# remove all rows where any column contains 'V'
diamonds %>%
  filter(across(everything(), ~ !grepl('V', .))) %>%
  head
#> # A tibble: 6 x 10
#>   carat cut     color clarity depth table price     x     y     z
#>   <dbl> <ord>   <ord> <ord>   <dbl> <dbl> <int> <dbl> <dbl> <dbl>
#> 1  0.23 Ideal   E     SI2      61.5    55   326  3.95  3.98  2.43
#> 2  0.21 Premium E     SI1      59.8    61   326  3.89  3.84  2.31
#> 3  0.31 Good    J     SI2      63.3    58   335  4.34  4.35  2.75
#> 4  0.3  Good    J     SI1      64      55   339  4.25  4.28  2.73
#> 5  0.22 Premium F     SI1      60.4    61   342  3.88  3.84  2.33
#> 6  0.31 Ideal   J     SI2      62.2    54   344  4.35  4.37  2.71

The now superseded syntax for the same would be:

diamonds %>% 
  filter_all(all_vars(!grepl('V', .))) %>%
  head

I tried to find an across alternative for the following, but I didn't immediately come up with a good solution:

    #get all rows where any column contains 'V'
    diamonds %>%
    filter_all(any_vars(grepl('V',.))) %>%
      head
    #> # A tibble: 6 x 10
    #>   carat cut       color clarity depth table price     x     y     z
    #>   <dbl> <ord>     <ord> <ord>   <dbl> <dbl> <int> <dbl> <dbl> <dbl>
    #> 1 0.23  Good      E     VS1      56.9    65   327  4.05  4.07  2.31
    #> 2 0.290 Premium   I     VS2      62.4    58   334  4.2   4.23  2.63
    #> 3 0.24  Very Good J     VVS2     62.8    57   336  3.94  3.96  2.48
    #> 4 0.24  Very Good I     VVS1     62.3    57   336  3.95  3.98  2.47
    #> 5 0.26  Very Good H     SI1      61.9    55   337  4.07  4.11  2.53
    #> 6 0.22  Fair      E     VS2      65.1    61   337  3.87  3.78  2.49

Update: Thanks to user Petr Kajzar in this answer, here also an approach for the above:

diamonds %>%
   filter(rowSums(across(everything(), ~grepl("V", .x))) > 0)

Where can I find a list of escape characters required for my JSON ajax return type?

From the spec:

All characters may be placed within the quotation marks except for the characters that must be escaped: quotation mark (U+0022), reverse solidus [backslash] (U+005C), and the control characters U+0000 to U+001F

Just because e.g. Bell (U+0007) doesn't have a single-character escape code does not mean that you don't need to escape it. Use the Unicode escape sequence \u0007.

What is a good pattern for using a Global Mutex in C#?

There is a race condition in the accepted answer when 2 processes running under 2 different users trying to initialize the mutex at the same time. After the first process initializes the mutex, if the second process tries to initialize the mutex before the first process sets the access rule to everyone, an unauthorized exception will be thrown by the second process.

See below for corrected answer:

using System.Runtime.InteropServices;   //GuidAttribute
using System.Reflection;                //Assembly
using System.Threading;                 //Mutex
using System.Security.AccessControl;    //MutexAccessRule
using System.Security.Principal;        //SecurityIdentifier

static void Main(string[] args)
{
    // get application GUID as defined in AssemblyInfo.cs
    string appGuid = ((GuidAttribute)Assembly.GetExecutingAssembly().GetCustomAttributes(typeof(GuidAttribute), false).GetValue(0)).Value.ToString();

    // unique id for global mutex - Global prefix means it is global to the machine
    string mutexId = string.Format( "Global\\{{{0}}}", appGuid );

    bool createdNew;
        // edited by Jeremy Wiebe to add example of setting up security for multi-user usage
        // edited by 'Marc' to work also on localized systems (don't use just "Everyone") 
        var allowEveryoneRule = new MutexAccessRule(new SecurityIdentifier(WellKnownSidType.WorldSid, null), MutexRights.FullControl, AccessControlType.Allow);
        var securitySettings = new MutexSecurity();
        securitySettings.AddAccessRule(allowEveryoneRule);

        using (var mutex = new Mutex(false, mutexId, out createdNew, securitySettings))
        {

        // edited by acidzombie24
        var hasHandle = false;
        try
        {
            try
            {
                // note, you may want to time out here instead of waiting forever
                // edited by acidzombie24
                // mutex.WaitOne(Timeout.Infinite, false);
                hasHandle = mutex.WaitOne(5000, false);
                if (hasHandle == false)
                    throw new TimeoutException("Timeout waiting for exclusive access");
            }
            catch (AbandonedMutexException)
            {
                // Log the fact the mutex was abandoned in another process, it will still get aquired
                hasHandle = true;
            }

            // Perform your work here.
        }
        finally
        {
            // edited by acidzombie24, added if statemnet
            if(hasHandle)
                mutex.ReleaseMutex();
        }
    }
}

jQuery scroll to ID from different page

I would like to recommend using the scrollTo plugin

http://demos.flesler.com/jquery/scrollTo/

You can the set scrollto by jquery css selector.

$('html,body').scrollTo( $(target), 800 );

I have had great luck with the accuracy of this plugin and its methods, where other methods of achieving the same effect like using .offset() or .position() have failed to be cross browser for me in the past. Not saying you can't use such methods, I'm sure there is a way to do it cross browser, I've just found scrollTo to be more reliable.

ssh "permissions are too open" error

As people have said, in Windows, I just dropped my pem file in C:\Users[user].ssh\ and that solved it. Although you can do chmod and other command line options from a bash or powershell prompt that didn't work. I didn't change rsa or anything else. Then when running the connection you have to put the path to the pem file in the .ssh folder:

ssh -i "C:\Users[user].ssh\ubuntukp01.pem" ubuntu@ec[ipaddress].us-west-2.compute.amazonaws.com

Initialize 2D array

How about something like this:

for (int row = 0; row < 3; row ++)
    for (int col = 0; col < 3; col++)
        table[row][col] = (char) ('1' + row * 3 + col);

The following complete Java program:

class Test {
    public static void main(String[] args) {
        char[][] table = new char[3][3];
        for (int row = 0; row < 3; row ++)
            for (int col = 0; col < 3; col++)
                table[row][col] = (char) ('1' + row * 3 + col);

        for (int row = 0; row < 3; row ++)
            for (int col = 0; col < 3; col++)
                System.out.println (table[row][col]);
    }
}

outputs:

1
2
3
4
5
6
7
8
9

This works because the digits in Unicode are consecutive starting at \u0030 (which is what you get from '0').

The expression '1' + row * 3 + col (where you vary row and col between 0 and 2 inclusive) simply gives you a character from 1 to 9.

Obviously, this won't give you the character 10 (since that's two characters) if you go further but it works just fine for the 3x3 case. You would have to change the method of generating the array contents at that point such as with something like:

String[][] table = new String[5][5];
for (int row = 0; row < 5; row ++)
    for (int col = 0; col < 5; col++)
        table[row][col] = String.format("%d", row * 5 + col + 1);

Check if element exists in jQuery

$('elemId').length doesn't work for me.

You need to put # before element id:

$('#elemId').length
---^

With vanilla JavaScript, you don't need the hash (#) e.g. document.getElementById('id_here') , however when using jQuery, you do need to put hash to target elements based on id just like CSS.

Custom date format with jQuery validation plugin

You can create your own custom validation method using the addMethod function. Say you wanted to validate "dd/mm/yyyy":

$.validator.addMethod(
    "australianDate",
    function(value, element) {
        // put your own logic here, this is just a (crappy) example
        return value.match(/^\d\d?\/\d\d?\/\d\d\d\d$/);
    },
    "Please enter a date in the format dd/mm/yyyy."
);

And then on your form add:

$('#myForm')
    .validate({
        rules : {
            myDate : {
                australianDate : true
            }
        }
    })
;

What data type to use in MySQL to store images?

Perfect answer for your question can be found on MYSQL site itself.refer their manual(without using PHP)

http://forums.mysql.com/read.php?20,17671,27914

According to them use LONGBLOB datatype. with that you can only store images less than 1MB only by default,although it can be changed by editing server config file.i would also recommend using MySQL workBench for ease of database management

How to update a pull request from forked repo?

Updating a pull request in GitHub is as easy as committing the wanted changes into existing branch (that was used with pull request), but often it is also wanted to squash the changes into single commit: 

git checkout yourbranch
git rebase -i origin/master

# Edit command names accordingly
  pick   1fc6c95 My pull request
  squash 6b2481b Hack hack - will be discarded
  squash dd1475d Also discarded

git push -f origin yourbranch

...and now the pull request contains only one commit.

Related links about rebasing:

Convert Mercurial project to Git

If you want to import your existing mercurial repository into a 'GitHub' repository, you can now simply use GitHub Importer available here [Login required]. No more messing around with fast-export etc. (although its a very good tool)

You will get all your commits, branches and tags intact. One more cool thing is that you can change the author's email-id as well. Check out below screenshots:

enter image description here

enter image description here

c# datatable insert column at position 0

 
    //Example to define how to do :

    DataTable dt = new DataTable();   

    dt.Columns.Add("ID");
    dt.Columns.Add("FirstName");
    dt.Columns.Add("LastName");
    dt.Columns.Add("Address");
    dt.Columns.Add("City");
           //  The table structure is:
            //ID    FirstName   LastName    Address     City

       //Now we want to add a PhoneNo column after the LastName column. For this we use the                               
             //SetOrdinal function, as iin:
        dt.Columns.Add("PhoneNo").SetOrdinal(3);

            //3 is the position number and positions start from 0.`enter code here`

               //Now the table structure will be:
              // ID      FirstName   LastName    PhoneNo    Address     City

App.Config change value

In addition to the answer by fenix2222 (which worked for me) I had to modify the last line to: 

config.Save(ConfigurationSaveMode.Modified);

Without this, the new value was still being written to the config file but the old value was retrieved when debugging.

Raising a number to a power in Java

Your calculation is likely the culprit. Try using:

bmi = weight / Math.pow(height / 100.0, 2.0);

Because both height and 100 are integers, you were likely getting the wrong answer when dividing. However, 100.0 is a double. I suggest you make weight a double as well. Also, the ^ operator is not for powers. Use the Math.pow() method instead.

c# regex matches example

This pattern should work:

#\d

foreach(var match in System.Text.RegularExpressions.RegEx.Matches(input, "#\d"))
{
    Console.WriteLine(match.Value);
}

(I'm not in front of Visual Studio, but even if that doesn't compile as-is, it should be close enough to tweak into something that works).

Best Timer for using in a Windows service

I agree with previous comment that might be best to consider a different approach. My suggest would be write a console application and use the windows scheduler:

This will:

  • Reduce plumbing code that replicates scheduler behaviour
  • Provide greater flexibility in terms of scheduling behaviour (e.g. only run on weekends) with all scheduling logic abstracted from application code
  • Utilise the command line arguments for parameters without having to setup configuration values in config files etc
  • Far easier to debug/test during development
  • Allow a support user to execute by invoking the console application directly (e.g. useful during support situations)

Positioning background image, adding padding

To add space before background image, one could define the 'width' of element which is using 'background-image' object. And then to define a pixel value in 'background-position' property to create space from left side.

For example, I'd a scenario where I got a navigation menu which had a bullet before link item and the bullet graphic were changeable if corrosponding link turns into an active state. Further, the active link also had a background-color to show, and this background-color had approximate 15px padding both on left and right side of link item (so on left, it includes bullet icon of link too).

While padding-right fulfill the purpose to have background-color stretched upto 15px more on right of link text. The padding-left only added to space between link text and bullet.

So I took the width of background-color object from PSD design (for ex. 82px) and added that to li element (in a class created to show active state) and then I set background-position value to 20px. Which resulted in bullet icon shifted inside from the left edge. And its provided me desired output of having left padding before bullet icon used as background image.

Please note, you may need to adjust your padding / margin values accordingly, which may used either for space between link items or for spacing between bullet icon and link text.

How to retrieve current workspace using Jenkins Pipeline Groovy script?

A quick note for anyone who is using bat in the job and needs to access Workspace:

It won't work.

$WORKSPACE https://issues.jenkins-ci.org/browse/JENKINS-33511 as mentioned here only works with PowerShell. So your code should have powershell for execution

 stage('Verifying Workspace') {
  powershell label: '', script: 'dir $WORKSPACE'
}

What is the (function() { } )() construct in JavaScript?

This is a more in depth explanation of why you would use this:

"The primary reason to use an IIFE is to obtain data privacy. Because JavaScript's var scopes variables to their containing function, any variables declared within the IIFE cannot be accessed by the outside world."

http://adripofjavascript.com/blog/drips/an-introduction-to-iffes-immediately-invoked-function-expressions.html

How to make Java 6, which fails SSL connection with "SSL peer shut down incorrectly", succeed like Java 7?

Remove "SSLv2ClientHello" from the enabled protocols on the client SSLSocket or HttpsURLConnection.

How to upsert (update or insert) in SQL Server 2005

You can use @@ROWCOUNT to check whether row should be inserted or updated:

update table1 
set name = 'val2', itemname = 'val3', itemcatName = 'val4', itemQty = 'val5'
where id = 'val1'
if @@ROWCOUNT = 0
insert into table1(id, name, itemname, itemcatName, itemQty)
values('val1', 'val2', 'val3', 'val4', 'val5')

in this case if update fails, the new row will be inserted

"unrecognized selector sent to instance" error in Objective-C

I got this issue trying some old format code in Swift3, 

let swipeRight = UISwipeGestureRecognizer(target: self, action: #selector(self.respond))

changing the action:"respond:" to action: #selector(self.respond) fixed the issue for me.

Create a rounded button / button with border-radius in Flutter

Now we have Icon Button to achieve rounded button click and overlay. However background color is not yet available but the same can be achieved by Circle avatar widget as follows:

CircleAvatar(
            backgroundColor: const Color(0xffF4F3FA),
            child: IconButton(
              onPressed: () => FlushbarHelper.createInformation(
                      message: 'Work in progress...')
                  .show(context),
              icon: Icon(Icons.more_vert),
            ),
          ),

Hope this helps some one.

Get all directories within directory nodejs

This answer does not use blocking functions like readdirSync or statSync. It does not use external dependencies nor find itself in the depths of callback hell.

Instead we use modern JavaScript conveniences like Promises and and async-await syntaxes. And asynchronous results are processed in parallel; not sequentially -

const { readdir, stat } =
  require ("fs") .promises

const { join } =
  require ("path")

const dirs = async (path = ".") =>
  (await stat (path)) .isDirectory ()
    ? Promise
        .all
          ( (await readdir (path))
              .map (p => dirs (join (path, p)))
          )
        .then
          ( results =>
              [] .concat (path, ...results)
          )
    : []

I'll install an example package, and then test our function -

$ npm install ramda
$ node

Let's see it work -

> dirs (".") .then (console.log, console.error)

[ '.'
, 'node_modules'
, 'node_modules/ramda'
, 'node_modules/ramda/dist'
, 'node_modules/ramda/es'
, 'node_modules/ramda/es/internal'
, 'node_modules/ramda/src'
, 'node_modules/ramda/src/internal'
]

Using a generalised module, Parallel, we can simplify the definition of dirs -

const Parallel =
  require ("./Parallel")

const dirs = async (path = ".") =>
  (await stat (path)) .isDirectory ()
    ? Parallel (readdir (path))
        .flatMap (f => dirs (join (path, f)))
        .then (results => [ path, ...results ])
    : []

The Parallel module used above was a pattern that was extracted from a set of functions designed to solve a similar problem. For more explanation, see this related Q&A.

Create directories using make file

make in, and off itself, handles directory targets just the same as file targets. So, it's easy to write rules like this:

outDir/someTarget: Makefile outDir
    touch outDir/someTarget

outDir:
    mkdir -p outDir

The only problem with that is, that the directories timestamp depends on what is done to the files inside. For the rules above, this leads to the following result:

$ make
mkdir -p outDir
touch outDir/someTarget
$ make
touch outDir/someTarget
$ make
touch outDir/someTarget
$ make
touch outDir/someTarget

This is most definitely not what you want. Whenever you touch the file, you also touch the directory. And since the file depends on the directory, the file consequently appears to be out of date, forcing it to be rebuilt.

However, you can easily break this loop by telling make to ignore the timestamp of the directory. This is done by declaring the directory as an order-only prerequsite:

# The pipe symbol tells make that the following prerequisites are order-only
#                           |
#                           v
outDir/someTarget: Makefile | outDir
    touch outDir/someTarget

outDir:
    mkdir -p outDir

This correctly yields:

$ make
mkdir -p outDir
touch outDir/someTarget
$ make
make: 'outDir/someTarget' is up to date.

TL;DR:

Write a rule to create the directory:

$(OUT_DIR):
    mkdir -p $(OUT_DIR)

And have the targets for the stuff inside depend on the directory order-only:

$(OUT_DIR)/someTarget: ... | $(OUT_DIR)

How do I search an SQL Server database for a string?

Here is how you can search the database in Swift using the FMDB library.

First, go to this link and add this to your project: FMDB. When you have done that, then here is how you do it. For example, you have a table called Person, and you have firstName and secondName and you want to find data by first name, here is a code for that:

    func loadDataByfirstName(firstName : String, completion: @escaping CompletionHandler){
    if isDatabaseOpened {
        let query = "select * from Person where firstName like '\(firstName)'"
        do {
            let results = try database.executeQuery(query, values: [firstName])
            while results.next() {
                let firstName = results.string(forColumn: "firstName") ?? ""
                let lastName = results.string(forColumn: "lastName") ?? ""
                let newPerson = Person(firstName: firstName, lastName: lastName)
                self.persons.append(newPerson)
            }
            completion(true)
        }catch let err {
            completion(false)
            print(err.localizedDescription)
        }
        database.close()
    }
}

Then in your ViewController you will write this to find the person detail you are looking for:

  override func viewWillAppear(_ animated: Bool) {
     super.viewWillAppear(animated)
      SQLManager.instance.openDatabase { (success) in
        if success {
            SQLManager.instance.loadDataByfirstName(firstName: "Hardi") { (success) in
                if success {
                    // You have your data Here
                }
            }
        }
    }
}

WSDL vs REST Pros and Cons

for enterprise systems in which your system is confined within your corporations, its easier and proper to use soap because you are almost in control of clients. it's easier since there a variety of tools which creates classes (proxies) and looks like you are doing your regular OOP which matches your java or .net environment (in which most corporates use).

I would use REST for internet facing applications for exposing interfaces (like twitter api) since clients can be using javascripts or html or others in which typing is not strict. REST being more liberal makes more sense.

Also for internet facing clients (world wide web), its easier to parse json or xml coming out of a rest interface rather than a purely xml coming from a soap interface. it's hard to use proxies on javascript and javascript does not naturally support objects. If you are using REST with javascript, you would just usually parse the json string and you're off. internet facing interfaces are usually very simple (so most of the time its simple parsing) and does not usually demand consistency that is why REST is adequate enough.

For enterprise applications I don't think REST is adequate because transactions, security, strict typing, schemas play a very important in enterprise applications development that is why SOAP is more suited for them.

My conclusion is that SOAP is for Enterprise systems, REST is for the Internet or WWW. You can use it interchangeably but you may find yourself having a difficult time eventually not using the correct tool for the job.

sorry for my bad english.

How to manage local vs production settings in Django?

The problem with most of these solutions is that you either have your local settings applied before the common ones, or after them.

So it's impossible to override things like

  • the env-specific settings define the addresses for the memcached pool, and in the main settings file this value is used to configure the cache backend
  • the env-specific settings add or remove apps/middleware to the default one

at the same time.

One solution can be implemented using "ini"-style config files with the ConfigParser class. It supports multiple files, lazy string interpolation, default values and a lot of other goodies. Once a number of files have been loaded, more files can be loaded and their values will override the previous ones, if any.

You load one or more config files, depending on the machine address, environment variables and even values in previously loaded config files. Then you just use the parsed values to populate the settings.

One strategy I have successfully used has been:

  • Load a default defaults.ini file
  • Check the machine name, and load all files which matched the reversed FQDN, from the shortest match to the longest match (so, I loaded net.ini, then net.domain.ini, then net.domain.webserver01.ini, each one possibly overriding values of the previous). This account also for developers' machines, so each one could set up its preferred database driver, etc. for local development
  • Check if there is a "cluster name" declared, and in that case load cluster.cluster_name.ini, which can define things like database and cache IPs

As an example of something you can achieve with this, you can define a "subdomain" value per-env, which is then used in the default settings (as hostname: %(subdomain).whatever.net) to define all the necessary hostnames and cookie things django needs to work.

This is as DRY I could get, most (existing) files had just 3 or 4 settings. On top of this I had to manage customer configuration, so an additional set of configuration files (with things like database names, users and passwords, assigned subdomain etc) existed, one or more per customer.

One can scale this as low or as high as necessary, you just put in the config file the keys you want to configure per-environment, and once there's need for a new config, put the previous value in the default config, and override it where necessary.

This system has proven reliable and works well with version control. It has been used for long time managing two separate clusters of applications (15 or more separate instances of the django site per machine), with more than 50 customers, where the clusters were changing size and members depending on the mood of the sysadmin...

How can I count the rows with data in an Excel sheet?

Try this scenario:

Array = A1:C7. A1-A3 have values, B2-B6 have value and C1, C3 and C6 have values.

To get a count of the number of rows add a column D (you can hide it after formulas are set up) and in D1 put formula =If(Sum(A1:C1)>0,1,0). Copy the formula from D1 through D7 (for others searching who are not excel literate, the numbers in the sum formula will change to the row you are on and this is fine).

Now in C8 make a sum formula that adds up the D column and the answer should be 6. For visually pleasing purposes hide column D.

What is the proper declaration of main in C++?

The exact wording of the latest published standard (C++14) is:

An implementation shall allow both

  • a function of () returning int and

  • a function of (int, pointer to pointer to char) returning int

as the type of main.

This makes it clear that alternative spellings are permitted so long as the type of main is the type int() or int(int, char**). So the following are also permitted:

  • int main(void)
  • auto main() -> int
  • int main ( )
  • signed int main()
  • typedef char **a; typedef int b, e; e main(b d, a c)

Open a PDF using VBA in Excel

Here is a simplified version of this script to copy a pdf into a XL file.


Sub CopyOnePDFtoExcel()

    Dim ws As Worksheet
    Dim PDF_path As String

    PDF_path = "C:\Users\...\Documents\This-File.pdf"


    'open the pdf file
    ActiveWorkbook.FollowHyperlink PDF_path

    SendKeys "^a", True
    SendKeys "^c"

    Call Shell("TaskKill /F /IM AcroRd32.exe", vbHide)

    Application.ScreenUpdating = False

    Set ws = ThisWorkbook.Sheets("Sheet1")

    ws.Activate
    ws.Range("A1").ClearContents
    ws.Range("A1").Select
    ws.Paste

    Application.ScreenUpdating = True

End Sub

javax.xml.bind.JAXBException: Class *** nor any of its super class is known to this context

This errors occurs when we use same method name for Jaxb2Marshaller for exemple:

    @Bean
    public Jaxb2Marshaller marshallerClient() {
        Jaxb2Marshaller marshaller = new Jaxb2Marshaller();
        // this package must match the package in the <generatePackage> specified in
        // pom.xml
        marshaller.setContextPath("library.io.github.walterwhites.loans");

        return marshaller;
    }

And on other file

    @Bean
    public Jaxb2Marshaller marshallerClient() {
        Jaxb2Marshaller marshaller = new Jaxb2Marshaller();
        // this package must match the package in the <generatePackage> specified in
        // pom.xml
        marshaller.setContextPath("library.io.github.walterwhites.client");

        return marshaller;
    }

Even It's different class, you should named them differently

How to get selenium to wait for ajax response?

Below is my code for fetch. Took me while researching because jQuery.active doesn't work with fetch. Here is the answer helped me proxy fetch, but its only for ajax not fetch mock for selenium

public static void customPatchXMLHttpRequest(WebDriver driver) {
    try {
        if (driver instanceof JavascriptExecutor) {
            JavascriptExecutor jsDriver = (JavascriptExecutor) driver;
            Object numberOfAjaxConnections = jsDriver.executeScript("return window.openHTTPs");
            if (numberOfAjaxConnections instanceof Long) {
                return;
            }
            String script = "  (function() {" + "var oldFetch = fetch;"
                    + "window.openHTTPs = 0; console.log('starting xhttps');" + "fetch = function(input,init ){ "
                    + "window.openHTTPs++; "

                    + "return oldFetch(input,init).then( function (response) {"
                    + "      if (response.status >= 200 && response.status < 300) {"
                    + "          window.openHTTPs--;  console.log('Call completed. Remaining active calls: '+ window.openHTTPs); return response;"
                    + "      } else {"
                    + "          window.openHTTPs--; console.log('Call fails. Remaining active calls: ' + window.openHTTPs);  return response;"
                    + "      };})" + "};" + "var oldOpen = XMLHttpRequest.prototype.open;"
                    + "XMLHttpRequest.prototype.open = function(method, url, async, user, pass) {"
                    + "window.openHTTPs++; console.log('xml ajax called');"
                    + "this.addEventListener('readystatechange', function() {" + "if(this.readyState == 4) {"
                    + "window.openHTTPs--; console.log('xml ajax complete');" + "}" + "}, false);"
                    + "oldOpen.call(this, method, url, async, user, pass);" + "}" +

                    "})();";
            jsDriver.executeScript(script);
        } else {
            System.out.println("Web driver: " + driver + " cannot execute javascript");
        }
    } catch (Exception e) {
        System.out.println(e);
    }
}

String contains another string

You can use .indexOf():

if(str.indexOf(substr) > -1) {

}

Responsive css styles on mobile devices ONLY

Why not use a media query range.

I'm currently working on a responsive layout for my employer and the ranges I'm using are as follows:

You have your main desktop styles in the body of the CSS file (1024px and above) and then for specific screen sizes I'm using:

@media all and (min-width:960px) and (max-width: 1024px) {
  /* put your css styles in here */
}

@media all and (min-width:801px) and (max-width: 959px) {
  /* put your css styles in here */
}

@media all and (min-width:769px) and (max-width: 800px) {
  /* put your css styles in here */
}

@media all and (min-width:569px) and (max-width: 768px) {
  /* put your css styles in here */
}

@media all and (min-width:481px) and (max-width: 568px) {
  /* put your css styles in here */
}

@media all and (min-width:321px) and (max-width: 480px) {
  /* put your css styles in here */
}

@media all and (min-width:0px) and (max-width: 320px) {
  /* put your css styles in here */
}

This will cover pretty much all devices being used - I would concentrate on getting the styling correct for the sizes at the end of the range (i.e. 320, 480, 568, 768, 800, 1024) as for all the others they will just be responsive to the size available.

Also, don't use px anywhere - use em's or %.

C# error: Use of unassigned local variable

The compiler doesn't know that the Environment.Exit() is going to terminate the program; it just sees you executing a static method on a class. Just initialize queue to null when you declare it.

Queue queue = null;

gnuplot plotting multiple line graphs

I think your problem is your version numbers. Try making 8.1 --> 8.01, and so forth. That should put the points in the right order.

Alternatively, you could plot using X, where X is the column number you want, instead of using 1:X. That will plot those values on the y axis and integers on the x axis. Try:

plot "ls.dat" using 2 title 'Removed' with lines, \
     "ls.dat" using 3 title 'Added' with lines, \
     "ls.dat" using 4 title 'Modified' with lines

Making LaTeX tables smaller?

As well as \singlespacing mentioned previously to reduce the height of the table, a useful way to reduce the width of the table is to add \tabcolsep=0.11cm before the \begin{tabular} command and take out all the vertical lines between columns. It's amazing how much space is used up between the columns of text. You could reduce the font size to something smaller than \small but I normally wouldn't use anything smaller than \footnotesize.

How do I format a date in VBA with an abbreviated month?

I'm using 

Sheet1.Range("E2", "E3000").NumberFormat = "dd/mm/yyyy hh:mm:ss"

to format a column

So I guess

Sheet1.Range("E2", "E3000").NumberFormat = "MMM dd yyyy"

would do the trick for you.

More: NumberFormat function.

How do I see what character set a MySQL database / table / column is?

For columns:

SHOW FULL COLUMNS FROM table_name;

Get file name from URL

If you want to get only the filename from a java.net.URL (not including any query parameters), you could use the following function:

public static String getFilenameFromURL(URL url) {
    return new File(url.getPath().toString()).getName();
}

For example, this input URL:

"http://example.com/image.png?version=2&amp;modificationDate=1449846324000"

Would be translated to this output String:

image.png

Guzzlehttp - How get the body of a response from Guzzle 6?

Guzzle implements PSR-7. That means that it will by default store the body of a message in a Stream that uses PHP temp streams. To retrieve all the data, you can use casting operator:

$contents = (string) $response->getBody();

You can also do it with

$contents = $response->getBody()->getContents();

The difference between the two approaches is that getContents returns the remaining contents, so that a second call returns nothing unless you seek the position of the stream with rewind or seek .

$stream = $response->getBody();
$contents = $stream->getContents(); // returns all the contents
$contents = $stream->getContents(); // empty string
$stream->rewind(); // Seek to the beginning
$contents = $stream->getContents(); // returns all the contents

Instead, usings PHP's string casting operations, it will reads all the data from the stream from the beginning until the end is reached.

$contents = (string) $response->getBody(); // returns all the contents
$contents = (string) $response->getBody(); // returns all the contents

Documentation: http://docs.guzzlephp.org/en/latest/psr7.html#responses

How can I tell when a MySQL table was last updated?

In later versions of MySQL you can use the information_schema database to tell you when another table was updated:

SELECT UPDATE_TIME
FROM   information_schema.tables
WHERE  TABLE_SCHEMA = 'dbname'
   AND TABLE_NAME = 'tabname'

This does of course mean opening a connection to the database.

An alternative option would be to "touch" a particular file whenever the MySQL table is updated:

On database updates:

  • Open your timestamp file in O_RDRW mode
  • close it again

or alternatively

  • use touch(), the PHP equivalent of the utimes() function, to change the file timestamp.

On page display:

  • use stat() to read back the file modification time.

How do I fix a "Expected Primary-expression before ')' token" error?

 
showInventory(player);     // I get the error here.

void showInventory(player& obj) {   // By Johnny :D

this means that player is an datatype and showInventory expect an referance to an variable of type player.

so the correct code will be

  void showInventory(player& obj) {   // By Johnny :D
    for(int i = 0; i < 20; i++) {
        std::cout << "\nINVENTORY:\n" + obj.getItem(i);
        i++;
        std::cout << "\t\t\t" + obj.getItem(i) + "\n";
        i++;
    }
    }

players myPlayers[10];

    std::string toDo() //BY KEATON
    {
    std::string commands[5] =   // This is the valid list of commands.
        {"help", "inv"};

    std::string ans;
    std::cout << "\nWhat do you wish to do?\n>> ";
    std::cin >> ans;

    if(ans == commands[0]) {
        helpMenu();
        return NULL;
    }
    else if(ans == commands[1]) {
        showInventory(myPlayers[0]);     // or any other index,also is not necessary to have an array
        return NULL;
    }

}

What are the Differences Between "php artisan dump-autoload" and "composer dump-autoload"?

Laravel's Autoload is a bit different:

1) It will in fact use Composer for some stuff

2) It will call Composer with the optimize flag

3) It will 'recompile' loads of files creating the huge bootstrap/compiled.php

4) And also will find all of your Workbench packages and composer dump-autoload them, one by one.

Recyclerview and handling different type of row inflation

You have to implement getItemViewType() method in RecyclerView.Adapter. By default onCreateViewHolder(ViewGroup parent, int viewType) implementation viewType of this method returns 0. Firstly you need view type of the item at position for the purposes of view recycling and for that you have to override getItemViewType() method in which you can pass viewType which will return your position of item. Code sample is given below

@Override
public MyViewholder onCreateViewHolder(ViewGroup parent, int viewType) {
    int listViewItemType = getItemViewType(viewType);
    switch (listViewItemType) {
         case 0: return new ViewHolder0(...);
         case 2: return new ViewHolder2(...);
    }
}

@Override
public int getItemViewType(int position) {   
    return position;
}

// and in the similar way you can set data according 
// to view holder position by passing position in getItemViewType
@Override
public void onBindViewHolder(MyViewholder viewholder, int position) {
    int listViewItemType = getItemViewType(position);
    // ...
}

How to use CURL via a proxy?

 
root@APPLICATIOSERVER:/var/www/html# php connectiontest.php
61e23468-949e-4103-8e08-9db09249e8s1 OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to 10.172.123.1:80 root@APPLICATIOSERVER:/var/www/html#

Post declaring the proxy settings in the php script file issue has been fixed.

$proxy = '10.172.123.1:80';
curl_setopt($cSession, CURLOPT_PROXY, $proxy); // PROXY details with port

How to parse month full form string using DateFormat in Java?

LocalDate from java.time

Use LocalDate from java.time, the modern Java date and time API, for a date

    DateTimeFormatter dateFormatter = DateTimeFormatter.ofPattern("MMMM d, u", Locale.ENGLISH);
    LocalDate date = LocalDate.parse("June 27, 2007", dateFormatter);
    System.out.println(date);

Output:

2007-06-27

As others have said already, remember to specify an English-speaking locale when your string is in English. A LocalDate is a date without time of day, so a lot better suitable for the date from your string than the old Date class. Despite its name a Date does not represent a date but a point in time that falls on at least two different dates in different time zones of the world.

Only if you need an old-fashioned Date for an API that you cannot afford to upgrade to java.time just now, convert like this:

    Instant startOfDay = date.atStartOfDay(ZoneId.systemDefault()).toInstant();
    Date oldfashionedDate = Date.from(startOfDay);
    System.out.println(oldfashionedDate);

Output in my time zone:

Wed Jun 27 00:00:00 CEST 2007

Link

Oracle tutorial: Date Time explaining how to use java.time.

How to create a file on Android Internal Storage?

I was getting the same exact error as well. Here is the fix. When you are specifying where to write to, Android will automatically resolve your path into either /data/ or /mnt/sdcard/. Let me explain.

If you execute the following statement:

File resolveMe = new File("/data/myPackage/files/media/qmhUZU.jpg");
resolveMe.createNewFile();

It will resolve the path to the root /data/ somewhere higher up in Android.

I figured this out, because after I executed the following code, it was placed automatically in the root /mnt/ without me translating anything on my own. 

File resolveMeSDCard = new File("/sdcard/myPackage/files/media/qmhUZU.jpg");
resolveMeSDCard.createNewFile();

A quick fix would be to change your following code:

File f = new File(getLocalPath().replace("/data/data/", "/"));

Hope this helps

Creating a BAT file for python script

This is the syntax: "python.exe path""python script path"pause

"C:\Users\hp\AppData\Local\Programs\Python\Python37\python.exe" "D:\TS_V1\TS_V2.py"
pause

Basically what will be happening the screen will appear for seconds and then go off take care of these 2 things:

  1. While saving the file you give extension as bat file but save it as a txt file and not all files and Encoding ANSI
  2. If the program still doesn't run save the batch file and the python script in same folder and specify the path of this folder in Environment Variables.

Clear the cache in JavaScript

You can also force the code to be reloaded every hour, like this, in PHP :

<?php
echo '<script language="JavaScript" src="js/myscript.js?token='.date('YmdH').'">';
?>

or

<script type="text/javascript" src="js/myscript.js?v=<?php echo date('YmdHis'); ?>"></script>

Copying files using rsync from remote server to local machine

If you have SSH access, you don't need to SSH first and then copy, just use Secure Copy (SCP) from the destination.

scp user@host:/path/file /localpath/file

Wild card characters are supported, so

scp user@host:/path/folder/* /localpath/folder

will copy all of the remote files in that folder.If copying more then one directory.

note -r will copy all sub-folders and content too.

How to create a QR code reader in a HTML5 website?

The algorithm that drives http://www.webqr.com is a JavaScript implementation of https://github.com/LazarSoft/jsqrcode. I haven't tried how reliable it is yet, but that's certainly the easier plug-and-play solution (client- or server-side) out of the two.

How can I get a file's size in C++?

If you're on Linux, seriously consider just using the g_file_get_contents function from glib. It handles all the code for loading a file, allocating memory, and handling errors.

Mysql: Select rows from a table that are not in another

 
SELECT a.* FROM 
FROM tbl_1 a
MINUS
SELECT b.* FROM 
FROM tbl_2 b

Eclipse does not start when I run the exe?

go to : "C:\workspace.metadata.plugins\org.eclipse.e4.workbench"

if already you save backup file "workbench.xmi" replace it else delete this.

Number of times a particular character appears in a string

You can do it inline, but you have to be careful with spaces in the column data. Better to use datalength()

SELECT 
  ColName, 
  DATALENGTH(ColName) -
  DATALENGTH(REPLACE(Col, 'A', '')) AS NumberOfLetterA
FROM ColName;

-OR- Do the replace with 2 characters

SELECT 
  ColName, 
  -LEN(ColName)
  +LEN(REPLACE(Col, 'A', '><')) AS NumberOfLetterA
FROM ColName;

Bootstrap 3 select input form inline

Thanks to G_money and other suggestions for this excellent solution to input-text with inline dropdown... here's another great solution.

<form class="form-inline" role="form" id="yourformID-form" action="" method="post">
    <div class="input-group">
        <span class="input-group-addon"><i class="fa fa-male"></i></span>

        <div class="form-group">
            <input size="50" maxlength="50" class="form-control" name="q" type="text">          
        </div>

        <div class="form-group">
            <select class="form-control" name="category">
                <option value=""></option>
                <option value="0">select1</option>
                <option value="1">select2</option>
                <option value="2">select3</option>
            </select>           
        </div>
    </div>
</form>

This works with Bootstrap 3: allowing input-text inline with a select dropdown. Here's what it looks like below...

enter image description here

How to add (vertical) divider to a horizontal LinearLayout?

In order to get drawn, divider of LinearLayout must have some height while ColorDrawable (which is essentially #00ff00 as well as any other hardcoded color) doesn't have. Simple (and correct) way to solve this, is to wrap your color into some Drawable with predefined height, such as shape drawable

Python dictionary : TypeError: unhashable type: 'list'

The error you gave is due to the fact that in python, dictionary keys must be immutable types (if key can change, there will be problems), and list is a mutable type.

Your error says that you try to use a list as dictionary key, you'll have to change your list into tuples if you want to put them as keys in your dictionary.

According to the python doc :

The only types of values not acceptable as keys are values containing lists or dictionaries or other mutable types that are compared by value rather than by object identity, the reason being that the efficient implementation of dictionaries requires a key’s hash value to remain constant

Isn't the size of character in Java 2 bytes?

Java allocates 2 of 2 bytes for character as it follows UTF-16. It occupies minimum 2 bytes while storing a character, and maximum of 4 bytes. There is no 1 byte or 3 bytes of storage for character.

Code coverage with Mocha

Blanket.js works perfect too.

npm install --save-dev blanket

in front of your test/tests.js

require('blanket')({
    pattern: function (filename) {
        return !/node_modules/.test(filename);
    }
});

run mocha -R html-cov > coverage.html

How to re import an updated package while in Python Interpreter?

Not sure if this does all expected things, but you can do just like that:

>>> del mymodule
>>> import mymodule

How to force a list to be vertical using html css

I would add this to the LI's CSS

.list-item
{
    float: left;
    clear: left;
}

Use of Java's Collections.singletonList()?

If an Immutable/Singleton collections refers to the one which having only one object and which is not further gets modified, then the same functionality can be achieved by making a collection "UnmodifiableCollection" having only one object. Since the same functionality can be achieved by Unmodifiable Collection with one object, then what special purpose the Singleton Collection serves for?

SQL ORDER BY multiple columns

The results are ordered by the first column, then the second, and so on for as many columns as the ORDER BY clause includes. If you want any results sorted in descending order, your ORDER BY clause must use the DESC keyword directly after the name or the number of the relevant column.

Check out this Example 

SELECT first_name, last_name, hire_date, salary 
FROM employee 
ORDER BY hire_date DESC,last_name ASC;

It will order in succession. Order the Hire_Date first, then LAST_NAME it by Hire_Date .

How to find Max Date in List<Object>?

self-explanatory style

import static java.util.Comparator.naturalOrder;
...

    list.stream()
        .map(User::getDate)
        .max(naturalOrder())
        .orElse(null)          // replace with .orElseThrow() is the list cannot be empty

Convert timestamp to date in Oracle SQL

This may not be the correct way to do it. But I have solved the problem using substring function.

Select max(start_ts), min(start_ts)from db where SUBSTR(start_ts, 0,9) ='13-may-2016'

using this I was able to retrieve the max and min timestamp.

How do you right-justify text in an HTML textbox?

Apply style="text-align: right" to the input tag. This will allow entry to be right-justified, and (at least in Firefox 3, IE 7 and Safari) will even appear to flow from the right.

How do malloc() and free() work?

Your program crashes because it used memory that does not belong to you. It may be used by someone else or not - if you are lucky you crash, if not the problem may stay hidden for a long time and come back and bite you later.

As far as malloc/free implementation goes - entire books are devoted to the topic. Basically the allocator would get bigger chunks of memory from the OS and manage them for you. Some of the problems an allocator must address are:

  • How to get new memory
  • How to store it - ( list or other structure, multiple lists for memory chunks of different size, and so on )
  • What to do if the user requests more memory than currently available ( request more memory from OS, join some of the existing blocks, how to join them exactly, ... )
  • What to do when the user frees memory
  • Debug allocators may give you bigger chunk that you requested and fill it some byte pattern, when you free the memory the allocator can check if wrote outside of the block ( which is probably happening in your case) ...

Why is Github asking for username/password when following the instructions on screen and pushing a new repo?

an additional note:

if you have already added a remote ($git remote add origin ... ) and need to change that particular remote then do a remote remove first ($ git remote rm origin), before re-adding the new and improved repo URL (where "origin" was the name for the remote repo).

so to use the original example :

$ git remote add origin https://github.com/WEMP/project-slideshow.git
$ git remote rm origin
$ git remote add origin https://[email protected]/WEMP/project-slideshow.git

Where can I find the Tomcat 7 installation folder on Linux AMI in Elastic Beanstalk?

Not sure if this would be helpful. I am using a similar Amazon Linux AMI, which has tomcat7 living under /usr/share/tomcat7.

If tomcat is already running on your machine you can try:

ps -ef | grep tomcat

or

ps -ef | grep java

to check where it's running from.

How to replace text of a cell based on condition in excel

You can use the IF statement in a new cell to replace text, such as:

=IF(A4="C", "Other", A4)

This will check and see if cell value A4 is "C", and if it is, it replaces it with the text "Other"; otherwise, it uses the contents of cell A4.

EDIT

Assuming that the Employee_Count values are in B1-B10, you can use this:

=IF(B1=LARGE($B$1:$B$10, 10), "Other", B1)

This function doesn't even require the data to be sorted; the LARGE function will find the 10th largest number in the series, and then the rest of the formula will compare against that.

How to create windows service from java jar?

The easiest solution I found for this so far is the Non-Sucking Service Manager

Usage would be 

nssm install <servicename> "C:\Program Files\Java\jre7\java.exe" "-jar <path-to-jar-file>"

How can I check if a program exists from a Bash script?

Command -v works fine if the POSIX_BUILTINS option is set for the <command> to test for, but it can fail if not. (It has worked for me for years, but I recently ran into one where it didn't work.)

I find the following to be more failproof:

test -x "$(which <command>)"

Since it tests for three things: path, existence and execution permission.

How to display a readable array - Laravel

actually a much easier way to get a readable array of what you (probably) want to see, is instead of using

dd($users);

or 

dd(User::all());

use this 

dd($users->toArray());

or

 dd(User::all()->toArray());

which is a lot nicer to debug with.

EDIT - additional, this also works nicely in your views / templates so if you pass the get all users to your template, you can then dump it into your blade template

{{ dd($users->toArray()) }}

What does the shrink-to-fit viewport meta attribute do?

As stats on iOS usage, indicating that iOS 9.0-9.2.x usage is currently at 0.17%. If these numbers are truly indicative of global use of these versions, then it’s even more likely to be safe to remove shrink-to-fit from your viewport meta tag.

After 9.2.x. IOS remove this tag check on its' browser.

You can check this page https://www.scottohara.me/blog/2018/12/11/shrink-to-fit.html

Select records from NOW() -1 Day

Didn't see any answers correctly using DATE_ADD or DATE_SUB:

Subtract 1 day from NOW()

...WHERE DATE_FIELD >= DATE_SUB(NOW(), INTERVAL 1 DAY)

Add 1 day from NOW()

...WHERE DATE_FIELD >= DATE_ADD(NOW(), INTERVAL 1 DAY)

What is the convention for word separator in Java package names?

The official naming conventions aren't that strict, they don't even 'forbid' camel case notation except for prefix (com in your example).

But I personally would avoid upper case letters and hyphenations, even numbers. I'd choose com.stackoverflow.mypackage like Bragboy suggested too.

(hyphenations '-' are not legal in package names)

EDIT

Interesting - the language specification has something to say about naming conventions too.

In Chapter 7.7 Unique Package Names we see examples with package names that consist of upper case letters (so CamelCase notation would be OK) and they suggest to replace hyphonation by an underscore ("mary-lou" -> "mary_lou") and prefix java keywords with an underscore ("com.example.enum" -> "com.example._enum")

Some more examples for upper case letters in package names can be found in chapter 6.8.1 Package Names.

What is the definition of "interface" in object oriented programming

In short, The basic problem an interface is trying to solve is to separate how we use something from how it is implemented. But you should consider interface is not a contract. Read more here.

Auto-fit TextView for Android

There's now an official solution to this problem. Autosizing TextViews introduced with Android O are available in the Support Library 26 and is backwards compatible all the way down to Android 4.0.

https://developer.android.com/preview/features/autosizing-textview.html

I'm not sure why https://stackoverflow.com/a/42940171/47680 which also included this information was deleted by an admin.

How to iterate through a list of objects in C++

Since C++ 11, you could do the following:

for(const auto& student : data)
{
  std::cout << student.name << std::endl;
}

Static variables in JavaScript

In JavaScript everything is either a primitive type or an object. Functions are objects — (key value pairs).

When you create a function you create two objects. One object that represents the function itself and the other that represents the prototype of the function.

Function is basically in that sense an object with the properties:

function name, 
arguments length 
and the functional prototype.

So where to set the static property: Two places, either inside the function object or inside the function prototype object.

Here is a snippet that creates that end even instantiates two instances, using the new JavaScript keyword.

_x000D_
_x000D_ 
function C () { // function_x000D_
  var privateProperty = "42";  _x000D_
  this.publicProperty = "39";  _x000D_
  _x000D_
  this.privateMethod = function(){ _x000D_
   console.log(privateProperty);_x000D_
  };_x000D_
}_x000D_
_x000D_
C.prototype.publicMethod = function () {    _x000D_
  console.log(this.publicProperty);_x000D_
};_x000D_
_x000D_
C.prototype.staticPrototypeProperty = "4";_x000D_
C.staticProperty = "3";_x000D_
_x000D_
_x000D_
var i1 = new C(); // instance 1_x000D_
var i2 = new C(); // instance 2_x000D_
_x000D_
i1.privateMethod();_x000D_
i1.publicMethod();_x000D_
_x000D_
console.log(i1.__proto__.staticPrototypeProperty);_x000D_
i1.__proto__.staticPrototypeProperty = "2";_x000D_
console.log(i2.__proto__.staticPrototypeProperty);_x000D_
_x000D_
console.log(i1.__proto__.constructor.staticProperty);_x000D_
i1.__proto__.constructor.staticProperty = "9";_x000D_
console.log(i2.__proto__.constructor.staticProperty);
_x000D_
_x000D_
_x000D_

The main idea is that instances i1 and i2 are using the same static properties.

Create a pointer to two-dimensional array

To fully understand this, you must grasp the following concepts:

Arrays are not pointers!

First of all (And it's been preached enough), arrays are not pointers. Instead, in most uses, they 'decay' to the address to their first element, which can be assigned to a pointer:

int a[] = {1, 2, 3};

int *p = a; // p now points to a[0]

I assume it works this way so that the array's contents can be accessed without copying all of them. That's just a behavior of array types and is not meant to imply that they are same thing.

Multidimensional arrays

Multidimensional arrays are just a way to 'partition' memory in a way that the compiler/machine can understand and operate on.

For instance, int a[4][3][5] = an array containing 4*3*5 (60) 'chunks' of integer-sized memory.

The advantage over using int a[4][3][5] vs plain int b[60] is that they're now 'partitioned' (Easier to work with their 'chunks', if needed), and the program can now perform bound checking.

In fact, int a[4][3][5] is stored exactly like int b[60] in memory - The only difference is that the program now manages it as if they're separate entities of certain sizes (Specifically, four groups of three groups of five).

Keep in mind: Both int a[4][3][5] and int b[60] are the same in memory, and the only difference is how they're handled by the application/compiler

{
  {1, 2, 3, 4, 5}
  {6, 7, 8, 9, 10}
  {11, 12, 13, 14, 15}
}
{
  {16, 17, 18, 19, 20}
  {21, 22, 23, 24, 25}
  {26, 27, 28, 29, 30}
}
{
  {31, 32, 33, 34, 35}
  {36, 37, 38, 39, 40}
  {41, 42, 43, 44, 45}
}
{
  {46, 47, 48, 49, 50}
  {51, 52, 53, 54, 55}
  {56, 57, 58, 59, 60}
}

From this, you can clearly see that each "partition" is just an array that the program keeps track of.

Syntax

Now, arrays are syntactically different from pointers. Specifically, this means the compiler/machine will treat them differently. This may seem like a no brainer, but take a look at this:

int a[3][3];

printf("%p %p", a, a[0]);

The above example prints the same memory address twice, like this:

0x7eb5a3b4 0x7eb5a3b4

However, only one can be assigned to a pointer so directly:

int *p1 = a[0]; // RIGHT !

int *p2 = a; // WRONG !

Why can't a be assigned to a pointer but a[0] can?

This, simply, is a consequence of multidimensional arrays, and I'll explain why:

At the level of 'a', we still see that we have another 'dimension' to look forward to. At the level of 'a[0]', however, we're already in the top dimension, so as far as the program is concerned we're just looking at a normal array.

You may be asking:

Why does it matter if the array is multidimensional in regards to making a pointer for it?

It's best to think this way:

A 'decay' from a multidimensional array is not just an address, but an address with partition data (AKA it still understands that its underlying data is made of other arrays), which consists of boundaries set by the array beyond the first dimension.

This 'partition' logic cannot exist within a pointer unless we specify it:

int a[4][5][95][8];

int (*p)[5][95][8];

p = a; // p = *a[0] // p = a+0

Otherwise, the meaning of the array's sorting properties are lost.

Also note the use of parenthesis around *p: int (*p)[5][95][8] - That's to specify that we're making a pointer with these bounds, not an array of pointers with these bounds: int *p[5][95][8]

Conclusion

Let's review:

  • Arrays decay to addresses if they have no other purpose in the used context
  • Multidimensional arrays are just arrays of arrays - Hence, the 'decayed' address will carry the burden of "I have sub dimensions"
  • Dimension data cannot exist in a pointer unless you give it to it.

In brief: multidimensional arrays decay to addresses that carry the ability to understand their contents.

What is a simple C or C++ TCP server and client example?

I've used Beej's Guide to Network Programming in the past. It's in C, not C++, but the examples are good. Go directly to section 6 for the simple client and server example programs.

Set background color in PHP?

just insert the following line and use any color you like

    echo "<body style='background-color:pink'>";

How to minify php page html output?

Thanks to Andrew. Here's what a did to use this in cakePHP:

  1. Download minify-2.1.7
  2. Unpack the file and copy min subfolder to cake's Vendor folder

  3. Creates MinifyCodeHelper.php in cake's View/Helper like this:

    App::import('Vendor/min/lib/Minify/', 'HTML');
App::import('Vendor/min/lib/Minify/', 'CommentPreserver');
App::import('Vendor/min/lib/Minify/CSS/', 'Compressor');
App::import('Vendor/min/lib/Minify/', 'CSS');
App::import('Vendor/min/lib/', 'JSMin');
class MinifyCodeHelper extends Helper {
    public function afterRenderFile($file, $data) {
        if( Configure::read('debug') < 1 ) //works only e production mode
            $data = Minify_HTML::minify($data, array(
                'cssMinifier' => array('Minify_CSS', 'minify'),
                'jsMinifier' => array('JSMin', 'minify')
            ));
        return $data;
    }
}

  4. Enabled my Helper in AppController

    public $helpers = array ('Html','...','MinifyCode');

5... Voila!

My conclusion: If apache's deflate and headers modules is disabled in your server your gain is 21% less size and 0.35s plus in request to compress (this numbers was in my case).

But if you had enable apache's modules the compressed response has no significant difference (1.3% to me) and the time to compress is the samne (0.3s to me).

So... why did I do that? 'couse my project's doc is all in comments (php, css and js) and my final user dont need to see this ;)

JSON Structure for List of Objects

As others mentioned, Justin's answer was close, but not quite right. I tested this using Visual Studio's "Paste JSON as C# Classes"

{
    "foos" : [
        {
            "prop1":"value1",
            "prop2":"value2"
        },
        {
            "prop1":"value3", 
            "prop2":"value4"
        }
    ]
}

Install tkinter for Python

The situation on macOS is still a bit complicated, but do-able:

Python.org strongly suggest downloading tkinter from ActiveState, but you should read their license first (hint: don't redistribute or want Support).

When the download is opened OS X 10.11 rejected it because it couldn't find my receipt: "ActiveTcl-8.6.pkg can’t be opened because it is from an unidentified developer".

I followed an OSXDaily fix from 2012 which suggested allowing from anywhere. But OS X has now added an "Open Anyway" option to allow (e.g.) Active-Tcl as a once off, and the "Anywhere" option has gained a timeout.

New warning for "Anywhere"

How to do scanf for single char in C

You have to use a valid variable. ch is not a valid variable for this program. Use char Aaa; 

char aaa;
scanf("%c",&Aaa);

Tested and it works.

javascript pushing element at the beginning of an array

Use .unshift() to add to the beginning of an array.

TheArray.unshift(TheNewObject);

See MDN for doc on unshift() and here for doc on other array methods.

FYI, just like there's .push() and .pop() for the end of the array, there's .shift() and .unshift() for the beginning of the array.

How to reference image resources in XAML?

One of the benefit of using the resource file is accessing the resources by names, so the image can change, the image name can change, as long as the resource is kept up to date correct image will show up.

Here is a cleaner approach to accomplish this: Assuming Resources.resx is in 'UI.Images' namespace, add the namespace reference in your xaml like this:

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:UI="clr-namespace:UI.Images"

Set your Image source like this:

<Image Source={Binding {x:Static UI:Resources.Search}} /> where 'Search' is name of the resource.

apache server reached MaxClients setting, consider raising the MaxClients setting

Did you consider using nginx (or other event based web server) instead of apache?

nginx shall allow higher number of connections and consume much less resources (as it is event based and does not create separate process per connection). Anyway, you will need some processes, doing real work (like WSGI servers or so) and if they stay on the same server as the front end web server, you only shift the performance problem to a bit different place.

Latest apache version shall allow similar solution (configure it in event based manner), but this is not my area of expertise.

Asserting successive calls to a mock method

Usually, I don't care about the order of the calls, only that they happened. In that case, I combine assert_any_call with an assertion about call_count.

>>> import mock
>>> m = mock.Mock()
>>> m(1)
<Mock name='mock()' id='37578160'>
>>> m(2)
<Mock name='mock()' id='37578160'>
>>> m(3)
<Mock name='mock()' id='37578160'>
>>> m.assert_any_call(1)
>>> m.assert_any_call(2)
>>> m.assert_any_call(3)
>>> assert 3 == m.call_count
>>> m.assert_any_call(4)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "[python path]\lib\site-packages\mock.py", line 891, in assert_any_call
    '%s call not found' % expected_string
AssertionError: mock(4) call not found

I find doing it this way to be easier to read and understand than a large list of calls passed into a single method.

If you do care about order or you expect multiple identical calls, assert_has_calls might be more appropriate.

Edit

Since I posted this answer, I've rethought my approach to testing in general. I think it's worth mentioning that if your test is getting this complicated, you may be testing inappropriately or have a design problem. Mocks are designed for testing inter-object communication in an object oriented design. If your design is not objected oriented (as in more procedural or functional), the mock may be totally inappropriate. You may also have too much going on inside the method, or you might be testing internal details that are best left unmocked. I developed the strategy mentioned in this method when my code was not very object oriented, and I believe I was also testing internal details that would have been best left unmocked.

Proper usage of Optional.ifPresent()

Why write complicated code when you could make it simple?

Indeed, if you are absolutely going to use the Optional class, the most simple code is what you have already written ...

if (user.isPresent())
{
    doSomethingWithUser(user.get());
}

This code has the advantages of being

  1. readable
  2. easy to debug (breakpoint)
  3. not tricky

Just because Oracle has added the Optional class in Java 8 doesn't mean that this class must be used in all situation.

How to set a hidden value in Razor

There is a Hidden helper alongside HiddenFor which lets you set the value. 

@Html.Hidden("RequiredProperty", "default")

EDIT Based on the edit you've made to the question, you could do this, but I believe you're moving into territory where it will be cheaper and more effective, in the long run, to fight for making the code change. As has been said, even by yourself, the controller or view model should be setting the default.

This code:

<ul>
@{
        var stacks = new System.Diagnostics.StackTrace().GetFrames();
        foreach (var frame in stacks)
        {
            <li>@frame.GetMethod().Name - @frame.GetMethod().DeclaringType</li>
        }
}
</ul>

Will give output like this:

Execute - ASP._Page_Views_ViewDirectoryX__SubView_cshtml
ExecutePageHierarchy - System.Web.WebPages.WebPageBase
ExecutePageHierarchy - System.Web.Mvc.WebViewPage
ExecutePageHierarchy - System.Web.WebPages.WebPageBase
RenderView - System.Web.Mvc.RazorView
Render - System.Web.Mvc.BuildManagerCompiledView
RenderPartialInternal - System.Web.Mvc.HtmlHelper
RenderPartial - System.Web.Mvc.Html.RenderPartialExtensions
Execute - ASP._Page_Views_ViewDirectoryY__MainView_cshtml

So assuming the MVC framework will always go through the same stack, you can grab var frame = stacks[8]; and use the declaring type to determine who your parent view is, and then use that determination to set (or not) the default value. You could also walk the stack instead of directly grabbing [8] which would be safer but even less efficient.

How to find the mysql data directory from command line in windows

Use bellow command from CLI interface

[root@localhost~]# mysqladmin variables -p<password> | grep datadir

Using Jquery AJAX function with datatype HTML

Here is a version that uses dataType html, but this is far less explicit, because i am returning an empty string to indicate an error.

Ajax call:

$.ajax({
  type : 'POST',
  url : 'post.php',
  dataType : 'html',
  data: {
      email : $('#email').val()
  },
  success : function(data){
      $('#waiting').hide(500);
      $('#message').removeClass().addClass((data == '') ? 'error' : 'success')
     .html(data).show(500);
      if (data == '') {
          $('#message').html("Format your email correcly");
          $('#demoForm').show(500);
      }
  },
  error : function(XMLHttpRequest, textStatus, errorThrown) {
      $('#waiting').hide(500);
      $('#message').removeClass().addClass('error')
      .text('There was an error.').show(500);
      $('#demoForm').show(500);
  }

});

post.php

<?php
sleep(1);

function processEmail($email) {
    if (preg_match("#^[a-zA-Z0-9_.-]+@[a-zA-Z0-9-]+.[a-zA-Z0-9-.]+$#", $email)) {
        // your logic here (ex: add into database)
        return true;
    }
    return false;
}

if (processEmail($_POST['email'])) {
    echo "<span>Your email is <strong>{$_POST['email']}</strong></span>";
}

Scatter plot and Color mapping in Python

Subplot Colorbar

For subplots with scatter, you can trick a colorbar onto your axes by building the "mappable" with the help of a secondary figure and then adding it to your original plot.

As a continuation of the above example:

import numpy as np
import matplotlib.pyplot as plt

x = np.arange(10)
y = x
t = x
fig, (ax1, ax2) = plt.subplots(1, 2)
ax1.scatter(x, y, c=t, cmap='viridis')
ax2.scatter(x, y, c=t, cmap='viridis_r')


# Build your secondary mirror axes:
fig2, (ax3, ax4) = plt.subplots(1, 2)

# Build maps that parallel the color-coded data
# NOTE 1: imshow requires a 2-D array as input
# NOTE 2: You must use the same cmap tag as above for it match
map1 = ax3.imshow(np.stack([t, t]),cmap='viridis')
map2 = ax4.imshow(np.stack([t, t]),cmap='viridis_r')

# Add your maps onto your original figure/axes
fig.colorbar(map1, ax=ax1)
fig.colorbar(map2, ax=ax2)
plt.show()

Scatter subplots with COLORBAR

Note that you will also output a secondary figure that you can ignore.

node.js - how to write an array to file

We can simply write the array data to the filesystem but this will raise one error in which ',' will be appended to the end of the file. To handle this below code can be used:

var fs = require('fs');

var file = fs.createWriteStream('hello.txt');
file.on('error', function(err) { Console.log(err) });
data.forEach(value => file.write(`${value}\r\n`));
file.end();

\r\n

is used for the new Line.

\n

won't help. Please refer this

How do I convert a string to a double in Python?

The decimal operator might be more in line with what you are looking for:

>>> from decimal import Decimal
>>> x = "234243.434"
>>> print Decimal(x)
234243.434

Concat scripts in order with Gulp

In my gulp setup, I'm specifying the vendor files first and then specifying the (more general) everything, second. And it successfully puts the vendor js before the other custom stuff.

gulp.src([
  // vendor folder first
  path.join(folder, '/vendor/**/*.js'),
  // custom js after vendor
  path.join(folder, '/**/*.js')
])

Scikit-learn: How to obtain True Positive, True Negative, False Positive and False Negative

if you have more than one classes in your classifier, you might want to use pandas-ml at that part. Confusion Matrix of pandas-ml give more detailed information. check that

RESULT

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

CMD (command prompt) can't go to the desktop

You need to use the change directory command 'cd' to change directory

cd C:\Users\MyName\Desktop

you can use cd \d to change the drive as well.

link for additional resources http://ss64.com/nt/cd.html

How to change the colors of a PNG image easily?

Photoshop - right click layer -> blending options -> color overlay change color and save

gnuplot : plotting data from multiple input files in a single graph

You may find that gnuplot's for loops are useful in this case, if you adjust your filenames or graph titles appropriately.

e.g.

filenames = "first second third fourth fifth"
plot for [file in filenames] file."dat" using 1:2 with lines

and

filename(n) = sprintf("file_%d", n)
plot for [i=1:10] filename(i) using 1:2 with lines

How to find the location of the Scheduled Tasks folder

There are multiple issues with the MMC however as on almost every PC in my business the ask scheduler API will not open and has somehow been corrupted. So you cannot edit, delete or otherwise modify tasks that were developed before the API decided not to run anymore. The only way we have found to fix that issue is to totally wipe away a persons profile under the C:\Users\ area and force the system to recreate the log in once the person logs back in. This seems to fix the API issue and it works again, however the tasks are often not visible anymore to that user since the tasks developed are specific to the user and not the machine in Windows 7. The other odd thing is that sometimes, although not with any frequency that can be analyzed, the tasks still run even though the API is corrupted and will not open. The cause of this issue is apparently not known but there are many "fixes" described on various websites, but the user profile deletion and adding anew seems to work every time for at least a little while. The tasks are saved as XML now in WIN 7, so if you do find them in the system32/tasks folder you can delete them, or copy them to a new drive and then import them back into task scheduler. We went with the system scheduler software from Splinterware though since we had the same corruption issue multiple times even with the fix that does not seem to be permanent.

How to set the min and max height or width of a Frame?

There is no single magic function to force a frame to a minimum or fixed size. However, you can certainly force the size of a frame by giving the frame a width and height. You then have to do potentially two more things: when you put this window in a container you need to make sure the geometry manager doesn't shrink or expand the window. Two, if the frame is a container for other widget, turn grid or pack propagation off so that the frame doesn't shrink or expand to fit its own contents.

Note, however, that this won't prevent you from resizing a window to be smaller than an internal frame. In that case the frame will just be clipped.

import Tkinter as tk

root = tk.Tk()
frame1 = tk.Frame(root, width=100, height=100, background="bisque")
frame2 = tk.Frame(root, width=50, height = 50, background="#b22222")

frame1.pack(fill=None, expand=False)
frame2.place(relx=.5, rely=.5, anchor="c")

root.mainloop()

HTML checkbox onclick called in Javascript

How about putting the checkbox into the label, making the label automatically "click sensitive" for the check box, and giving the checkbox a onchange event?

<label ..... ><input type="checkbox" onchange="toggleCheckbox(this)" .....> 

function toggleCheckbox(element)
 {
   element.checked = !element.checked;
 }

This will additionally catch users using a keyboard to toggle the check box, something onclick would not.

"Uncaught Error: [$injector:unpr]" with angular after deployment

This problem occurs when the controller or directive are not specified as a array of dependencies and function. For example

angular.module("appName").directive('directiveName', function () {
    return {
        restrict: 'AE',
        templateUrl: 'calender.html',
        controller: function ($scope) {
            $scope.selectThisOption = function () {
                // some code
            };
        }
    };
});

When minified The '$scope' passed to the controller function is replaced by a single letter variable name . This will render angular clueless of the dependency . To avoid this pass the dependency name along with the function as a array.

angular.module("appName").directive('directiveName', function () {
    return {
        restrict: 'AE',
        templateUrl: 'calender.html'
        controller: ['$scope', function ($scope) { //<-- difference
            $scope.selectThisOption = function () {
                // some code
            };
        }]
    };
});

Objective-C - Remove last character from string

If it's an NSMutableString (which I would recommend since you're changing it dynamically), you can use:

[myString deleteCharactersInRange:NSMakeRange([myRequestString length]-1, 1)];

Difference between adjustResize and adjustPan in android?

You can use android:windowSoftInputMode="stateAlwaysHidden|adjustResize" in AndroidManifest.xml for your current activity, and use android:fitsSystemWindows="true" in styles or rootLayout.

NSAttributedString add text alignment

Swift 4 answer:

// Define paragraph style - you got to pass it along to NSAttributedString constructor
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.alignment = .center

// Define attributed string attributes
let attributes = [NSAttributedStringKey.paragraphStyle: paragraphStyle]

let attributedString = NSAttributedString(string:"Test", attributes: attributes)

Converting BigDecimal to Integer

TL;DR

Use one of these for universal conversion needs

//Java 7 or below
bigDecimal.setScale(0, RoundingMode.DOWN).intValueExact()
//Java 8    
bigDecimal.toBigInteger().intValueExact()

Reasoning

The answer depends on what the requirements are and how you answer these question.

  • Will the BigDecimal potentially have a non-zero fractional part?
  • Will the BigDecimal potentially not fit into the Integer range?
  • Would you like non-zero fractional parts rounded or truncated?
  • How would you like non-zero fractional parts rounded?

If you answered no to the first 2 questions, you could just use BigDecimal.intValueExact() as others have suggested and let it blow up when something unexpected happens.

If you are not absolutely 100% confident about question number 2, then intValue() is always the wrong answer.

Making it better

Let's use the following assumptions based on the other answers.

  • We are okay with losing precision and truncating the value because that's what intValueExact() and auto-boxing do
  • We want an exception thrown when the BigDecimal is larger than the Integer range because anything else would be crazy unless you have a very specific need for the wrap around that happens when you drop the high-order bits.

Given those params, intValueExact() throws an exception when we don't want it to if our fractional part is non-zero. On the other hand, intValue() doesn't throw an exception when it should if our BigDecimal is too large.

To get the best of both worlds, round off the BigDecimal first, then convert. This also has the benefit of giving you more control over the rounding process.

Spock Groovy Test

void 'test BigDecimal rounding'() {
    given:
    BigDecimal decimal = new BigDecimal(Integer.MAX_VALUE - 1.99)
    BigDecimal hugeDecimal = new BigDecimal(Integer.MAX_VALUE + 1.99)
    BigDecimal reallyHuge = new BigDecimal("10000000000000000000000000000000000000000000000")
    String decimalAsBigIntString = decimal.toBigInteger().toString()
    String hugeDecimalAsBigIntString = hugeDecimal.toBigInteger().toString()
    String reallyHugeAsBigIntString = reallyHuge.toBigInteger().toString()

    expect: 'decimals that can be truncated within Integer range to do so without exception'
    //GOOD: Truncates without exception
    '' + decimal.intValue() == decimalAsBigIntString
    //BAD: Throws ArithmeticException 'Non-zero decimal digits' because we lose information
    // decimal.intValueExact() == decimalAsBigIntString
    //GOOD: Truncates without exception
    '' + decimal.setScale(0, RoundingMode.DOWN).intValueExact() == decimalAsBigIntString

    and: 'truncated decimal that cannot be truncated within Integer range throw conversionOverflow exception'
    //BAD: hugeDecimal.intValue() is -2147483648 instead of 2147483648
    //'' + hugeDecimal.intValue() == hugeDecimalAsBigIntString
    //BAD: Throws ArithmeticException 'Non-zero decimal digits' because we lose information
    //'' + hugeDecimal.intValueExact() == hugeDecimalAsBigIntString
    //GOOD: Throws conversionOverflow ArithmeticException because to large
    //'' + hugeDecimal.setScale(0, RoundingMode.DOWN).intValueExact() == hugeDecimalAsBigIntString

    and: 'truncated decimal that cannot be truncated within Integer range throw conversionOverflow exception'
    //BAD: hugeDecimal.intValue() is 0
    //'' + reallyHuge.intValue() == reallyHugeAsBigIntString
    //GOOD: Throws conversionOverflow ArithmeticException because to large
    //'' + reallyHuge.intValueExact() == reallyHugeAsBigIntString
    //GOOD: Throws conversionOverflow ArithmeticException because to large
    //'' + reallyHuge.setScale(0, RoundingMode.DOWN).intValueExact() == reallyHugeAsBigIntString

    and: 'if using Java 8, BigInteger has intValueExact() just like BigDecimal'
    //decimal.toBigInteger().intValueExact() == decimal.setScale(0, RoundingMode.DOWN).intValueExact()
}

How to add a second css class with a conditional value in razor MVC 4

This:

    <div class="details @(Model.Details.Count > 0 ? "show" : "hide")">

will render this:

    <div class="details hide">

and is the mark-up I want.

how to do bitwise exclusive or of two strings in python?

If you want to operate on bytes or words then you'll be better to use Python's array type instead of a string. If you are working with fixed length blocks then you may be able to use H or L format to operate on words rather than bytes, but I just used 'B' for this example:

>>> import array
>>> a1 = array.array('B', 'Hello, World!')
>>> a1
array('B', [72, 101, 108, 108, 111, 44, 32, 87, 111, 114, 108, 100, 33])
>>> a2 = array.array('B', ('secret'*3))
>>> for i in range(len(a1)):
    a1[i] ^= a2[i]


>>> a1.tostring()
';\x00\x0f\x1e\nXS2\x0c\x00\t\x10R'

How to change font-size of a tag using inline css?

use this attribute in style

font-size: 11px !important;//your font size

by !important it override your css

Hibernate JPA Sequence (non-Id)

I fixed the generation of UUID (or sequences) with Hibernate using @PrePersist annotation:

@PrePersist
public void initializeUUID() {
    if (uuid == null) {
        uuid = UUID.randomUUID().toString();
    }
}

Algorithm for solving Sudoku

There are four steps to solve a sudoku puzzle:

  1. Identify all possibilities for each cell (getting from the row, column and box) and try to develop a possible matrix. 2.Check for double pair, if it exists then remove these two values from all the cells in that row/column/box, wherever the pair exists If any cell is having single possiblity then assign that run step 1 again
  2. Check for each cell with each row, column and box. If the cell has one value which does not belong in the other possible values then assign that value to that cell. run step 1 again
  3. If the sudoku is still not solved, then we need to start the following assumption, Assume the first possible value and assign. Then run step 1–3 If still not solved then do it for next possible value and run it in recursion.
  4. If the sudoku is still not solved, then we need to start the following assumption, Assume the first possible value and assign. Then run step 1–3

If still not solved then do it for next possible value and run it in recursion.

import math
import sys


def is_solved(l):
    for x, i in enumerate(l):
        for y, j in enumerate(i):
            if j == 0:
                # Incomplete
                return None
            for p in range(9):
                if p != x and j == l[p][y]:
                    # Error
                    print('horizontal issue detected!', (x, y))
                    return False
                if p != y and j == l[x][p]:
                    # Error
                    print('vertical issue detected!', (x, y))
                    return False
            i_n, j_n = get_box_start_coordinate(x, y)
            for (i, j) in [(i, j) for p in range(i_n, i_n + 3) for q in range(j_n, j_n + 3)
                           if (p, q) != (x, y) and j == l[p][q]]:
                    # Error
                print('box issue detected!', (x, y))
                return False
    # Solved
    return True


def is_valid(l):
    for x, i in enumerate(l):
        for y, j in enumerate(i):
            if j != 0:
                for p in range(9):
                    if p != x and j == l[p][y]:
                        # Error
                        print('horizontal issue detected!', (x, y))
                        return False
                    if p != y and j == l[x][p]:
                        # Error
                        print('vertical issue detected!', (x, y))
                        return False
                i_n, j_n = get_box_start_coordinate(x, y)
                for (i, j) in [(i, j) for p in range(i_n, i_n + 3) for q in range(j_n, j_n + 3)
                               if (p, q) != (x, y) and j == l[p][q]]:
                        # Error
                    print('box issue detected!', (x, y))
                    return False
    # Solved
    return True


def get_box_start_coordinate(x, y):
    return 3 * int(math.floor(x/3)), 3 * int(math.floor(y/3))


def get_horizontal(x, y, l):
    return [l[x][i] for i in range(9) if l[x][i] > 0]


def get_vertical(x, y, l):
    return [l[i][y] for i in range(9) if l[i][y] > 0]


def get_box(x, y, l):
    existing = []
    i_n, j_n = get_box_start_coordinate(x, y)
    for (i, j) in [(i, j) for i in range(i_n, i_n + 3) for j in range(j_n, j_n + 3)]:
        existing.append(l[i][j]) if l[i][j] > 0 else None
    return existing


def detect_and_simplify_double_pairs(l, pl):
    for (i, j) in [(i, j) for i in range(9) for j in range(9) if len(pl[i][j]) == 2]:
        temp_pair = pl[i][j]
        for p in (p for p in range(j+1, 9) if len(pl[i][p]) == 2 and len(set(pl[i][p]) & set(temp_pair)) == 2):
            for q in (q for q in range(9) if q != j and q != p):
                pl[i][q] = list(set(pl[i][q]) - set(temp_pair))
                if len(pl[i][q]) == 1:
                    l[i][q] = pl[i][q].pop()
                    return True
        for p in (p for p in range(i+1, 9) if len(pl[p][j]) == 2 and len(set(pl[p][j]) & set(temp_pair)) == 2):
            for q in (q for q in range(9) if q != i and p != q):
                pl[q][j] = list(set(pl[q][j]) - set(temp_pair))
                if len(pl[q][j]) == 1:
                    l[q][j] = pl[q][j].pop()
                    return True
        i_n, j_n = get_box_start_coordinate(i, j)
        for (a, b) in [(a, b) for a in range(i_n, i_n+3) for b in range(j_n, j_n+3)
                       if (a, b) != (i, j) and len(pl[a][b]) == 2 and len(set(pl[a][b]) & set(temp_pair)) == 2]:
            for (c, d) in [(c, d) for c in range(i_n, i_n+3) for d in range(j_n, j_n+3)
                           if (c, d) != (a, b) and (c, d) != (i, j)]:
                pl[c][d] = list(set(pl[c][d]) - set(temp_pair))
                if len(pl[c][d]) == 1:
                    l[c][d] = pl[c][d].pop()
                    return True
    return False


def update_unique_horizontal(x, y, l, pl):
    tl = pl[x][y]
    for i in (i for i in range(9) if i != y):
        tl = list(set(tl) - set(pl[x][i]))
    if len(tl) == 1:
        l[x][y] = tl.pop()
        return True
    return False


def update_unique_vertical(x, y, l, pl):
    tl = pl[x][y]
    for i in (i for i in range(9) if i != x):
        tl = list(set(tl) - set(pl[i][y]))
    if len(tl) == 1:
        l[x][y] = tl.pop()
        return True
    return False


def update_unique_box(x, y, l, pl):
    tl = pl[x][y]
    i_n, j_n = get_box_start_coordinate(x, y)
    for (i, j) in [(i, j) for i in range(i_n, i_n+3) for j in range(j_n, j_n+3) if (i, j) != (x, y)]:
        tl = list(set(tl) - set(pl[i][j]))
    if len(tl) == 1:
        l[x][y] = tl.pop()
        return True
    return False


def find_and_place_possibles(l):
    while True:
        pl = populate_possibles(l)
        if pl != False:
            return pl


def populate_possibles(l):
    pl = [[[]for j in i] for i in l]
    for (i, j) in [(i, j) for i in range(9) for j in range(9) if l[i][j] == 0]:
        p = list(set(range(1, 10)) - set(get_horizontal(i, j, l) +
                                         get_vertical(i, j, l) + get_box(i, j, l)))
        if len(p) == 1:
            l[i][j] = p.pop()
            return False
        else:
            pl[i][j] = p
    return pl


def find_and_remove_uniques(l, pl):
    for (i, j) in [(i, j) for i in range(9) for j in range(9) if l[i][j] == 0]:
        if update_unique_horizontal(i, j, l, pl) == True:
            return True
        if update_unique_vertical(i, j, l, pl) == True:
            return True
        if update_unique_box(i, j, l, pl) == True:
            return True
    return False


def try_with_possibilities(l):
    while True:
        improv = False
        pl = find_and_place_possibles(l)
        if detect_and_simplify_double_pairs(
                l, pl) == True:
            continue
        if find_and_remove_uniques(
                l, pl) == True:
            continue
        if improv == False:
            break
    return pl


def get_first_conflict(pl):
    for (x, y) in [(x, y) for x, i in enumerate(pl) for y, j in enumerate(i) if len(j) > 0]:
        return (x, y)


def get_deep_copy(l):
    new_list = [i[:] for i in l]
    return new_list


def run_assumption(l, pl):
    try:
        c = get_first_conflict(pl)
        fl = pl[c[0]
                ][c[1]]
        # print('Assumption Index : ', c)
        # print('Assumption List: ',  fl)
    except:
        return False
    for i in fl:
        new_list = get_deep_copy(l)
        new_list[c[0]][c[1]] = i
        new_pl = try_with_possibilities(new_list)
        is_done = is_solved(new_list)
        if is_done == True:
            l = new_list
            return new_list
        else:
            new_list = run_assumption(new_list, new_pl)
            if new_list != False and is_solved(new_list) == True:
                return new_list
    return False


if __name__ == "__main__":
    l = [
        [0, 0, 0, 0, 0, 0, 0, 0, 0],
        [0, 0, 8, 0, 0, 0, 0, 4, 0],
        [0, 0, 0, 0, 0, 0, 0, 0, 0],
        [0, 0, 0, 0, 0, 6, 0, 0, 0],
        [0, 0, 0, 0, 0, 0, 0, 0, 0],
        [0, 0, 0, 0, 0, 0, 0, 0, 0],
        [2, 0, 0, 0, 0, 0, 0, 0, 0],
        [0, 0, 0, 0, 0, 0, 2, 0, 0],
        [0, 0, 0, 0, 0, 0, 0, 0, 0]
    ]
    # This puzzle copied from Hacked rank test case
    if is_valid(l) == False:
        print("Sorry! Invalid.")
        sys.exit()
    pl = try_with_possibilities(l)
    is_done = is_solved(l)
    if is_done == True:
        for i in l:
            print(i)
        print("Solved!!!")
        sys.exit()

    print("Unable to solve by traditional ways")
    print("Starting assumption based solving")
    new_list = run_assumption(l, pl)
    if new_list != False:
        is_done = is_solved(new_list)
        print('is solved ? - ', is_done)
        for i in new_list:
            print(i)
        if is_done == True:
            print("Solved!!! with assumptions.")
        sys.exit()
    print(l)
    print("Sorry! No Solution. Need to fix the valid function :(")
    sys.exit()

How to use Lambda in LINQ select statement

Why not just use all Lambda syntax?

database.Stores.Where(s => s.CompanyID == curCompany.ID)
               .Select(s => new SelectListItem
                   {
                       Value = s.Name,
                       Text = s.ID
                   });

How To have Dynamic SQL in MySQL Stored Procedure

I don't believe MySQL supports dynamic sql. You can do "prepared" statements which is similar, but different.

Here is an example:

mysql> PREPARE stmt FROM 
    -> 'select count(*) 
    -> from information_schema.schemata 
    -> where schema_name = ? or schema_name = ?'
;
Query OK, 0 rows affected (0.00 sec)
Statement prepared
mysql> EXECUTE stmt 
    -> USING @schema1,@schema2
+----------+
| count(*) |
+----------+
|        2 |
+----------+
1 row in set (0.00 sec)
mysql> DEALLOCATE PREPARE stmt;

The prepared statements are often used to see an execution plan for a given query. Since they are executed with the execute command and the sql can be assigned to a variable you can approximate the some of the same behavior as dynamic sql.

Here is a good link about this:

Don't forget to deallocate the stmt using the last line!

Good Luck!

Responding with a JSON object in Node.js (converting object/array to JSON string)

 
const http = require('http');
const url = require('url');

http.createServer((req,res)=>{

    const parseObj =  url.parse(req.url,true);
    const users = [{id:1,name:'soura'},{id:2,name:'soumya'}]

    if(parseObj.pathname == '/user-details' && req.method == "GET") {
        let Id = parseObj.query.id;
        let user_details = {};
        users.forEach((data,index)=>{
            if(data.id == Id){
                user_details = data;
            }
        })
        res.writeHead(200,{'x-auth-token':'Auth Token'})
        res.write(JSON.stringify(user_details)) // Json to String Convert
        res.end();
    }
}).listen(8000);

I have used the above code in my existing project.

jQuery SVG vs. Raphael

Raphael is definitely easier to set up and get going, but note that there are ways of expressing things in SVG that are not possible in Raphael. As noted above there are no "groups". This implies that you can't implement layers of Coordinate Transfomations. Instead there is only one coordinate transform available.

If your design depends on nested coordinate transforms, Raphael is not for you.

Error installing mysql2: Failed to build gem native extension

On Ubuntu/Debian and other distributions using aptitude:

sudo apt-get install libmysql-ruby libmysqlclient-dev

Package libmysql-ruby has been phased out and replaced by ruby-mysql. This is where I found the solution.

If the above command doesn't work because libmysql-ruby cannot be found, the following should be sufficient:

sudo apt-get install libmysqlclient-dev

On Red Hat/CentOS and other distributions using yum:

sudo yum install mysql-devel

On Mac OS X with Homebrew:

brew install mysql

How can I monitor the thread count of a process on linux?

To get the number of threads for a given pid:

$ ps -o nlwp <pid>

Where nlwp stands for Number of Light Weight Processes (threads). Thus ps aliases nlwp to thcount, which means that

$ ps -o thcount <pid>

does also work.

If you want to monitor the thread count, simply use watch:

$ watch ps -o thcount <pid>

To get the sum of all threads running in the system:

$ ps -eo nlwp | tail -n +2 | awk '{ num_threads += $1 } END { print num_threads }'

C# Dictionary get item by index

You can take keys or values per index:

int value = _dict.Values.ElementAt(5);//ElementAt value should be <= _dict.Count - 1
string key = _dict.Keys.ElementAt(5);//ElementAt value should be  < =_dict.Count - 1

Update a dataframe in pandas while iterating row by row

Well, if you are going to iterate anyhow, why don't use the simplest method of all, df['Column'].values[i]

df['Column'] = ''

for i in range(len(df)):
    df['Column'].values[i] = something/update/new_value

Or if you want to compare the new values with old or anything like that, why not store it in a list and then append in the end.

mylist, df['Column'] = [], ''

for <condition>:
    mylist.append(something/update/new_value)

df['Column'] = mylist

What is a tracking branch?

This was how I added a tracking branch so I can pull from it into my new branch:

git branch --set-upstream-to origin/Development new-branch

Error pushing to GitHub - insufficient permission for adding an object to repository database

 
 user@M063:/var/www/html/app/.git/objects$ sudo chmod 777 -R .git/objects
 user@M063:/var/www/html/app/.git/objects$ sudo chown -R user:user .git/objects/

How to change active class while click to another link in bootstrap use jquery?

This will do the trick

 $(document).ready(function () {
        var url = window.location;
        var element = $('ul.nav a').filter(function() {
            return this.href == url || url.href.indexOf(this.href) == 0;
        }).addClass('active').parent().parent().addClass('in').parent();
        if (element.is('li')) {
            element.addClass('active');
        }
    });

How do I disable a Button in Flutter?

Enable and Disable functionality is same for most of the widgets.

Ex, button , switch, checkbox etc.

Just set the onPressed property as shown below

onPressed : null returns Disabled widget

onPressed : (){} or onPressed : _functionName returns Enabled widget

What is a good way to handle exceptions when trying to read a file in python?

I guess I misunderstood what was being asked. Re-re-reading, it looks like Tim's answer is what you want. Let me just add this, however: if you want to catch an exception from open, then open has to be wrapped in a try. If the call to open is in the header of a with, then the with has to be in a try to catch the exception. There's no way around that.

So the answer is either: "Tim's way" or "No, you're doing it correctly.".

Previous unhelpful answer to which all the comments refer:

import os

if os.path.exists(fName):
   with open(fName, 'rb') as f:
       try:
           # do stuff
       except : # whatever reader errors you care about
           # handle error

LINQ query to return a Dictionary<string, string>

Use the ToDictionary method directly.

var result = 
  // as Jon Skeet pointed out, OrderBy is useless here, I just leave it 
  // show how to use OrderBy in a LINQ query
  myClassCollection.OrderBy(mc => mc.SomePropToSortOn)
                   .ToDictionary(mc => mc.KeyProp.ToString(), 
                                 mc => mc.ValueProp.ToString(), 
                                 StringComparer.OrdinalIgnoreCase);

How to reliably open a file in the same directory as a Python script

To quote from the Python documentation:

As initialized upon program startup, the first item of this list, path[0], is the directory containing the script that was used to invoke the Python interpreter. If the script directory is not available (e.g. if the interpreter is invoked interactively or if the script is read from standard input), path[0] is the empty string, which directs Python to search modules in the current directory first. Notice that the script directory is inserted before the entries inserted as a result of PYTHONPATH.

sys.path[0] is what you are looking for.

C# Collection was modified; enumeration operation may not execute

As others have pointed out, you are modifying a collection that you are iterating over and that's what's causing the error. The offending code is below:

foreach (KeyValuePair<int, int> kvp in rankings)
{
    .....

    if((double)(similarModules/modules.Count)>0.6)
    {
        rankings[kvp.Key] = rankings[kvp.Key] + 4;  // <--- This line is the problem
    }
    .....

What may not be obvious from the code above is where the Enumerator comes from. In a blog post from a few years back about Eric Lippert provides an example of what a foreach loop gets expanded to by the compiler. The generated code will look something like:

{
    IEnumerator<int> e = ((IEnumerable<int>)values).GetEnumerator(); // <-- This
                                                       // is where the Enumerator
                                                       // comes from.
    try
    { 
        int m; // OUTSIDE THE ACTUAL LOOP in C# 4 and before, inside the loop in 5
        while(e.MoveNext())
        {
            // loop code goes here
        }
    }
    finally
    { 
      if (e != null) ((IDisposable)e).Dispose();
    }
}

If you look up the MSDN documentation for IEnumerable (which is what GetEnumerator() returns) you will see:

Enumerators can be used to read the data in the collection, but they cannot be used to modify the underlying collection.

Which brings us back to what the error message states and the other answers re-state, you're modifying the underlying collection.

MySQL: #1075 - Incorrect table definition; autoincrement vs another key?

Identified this solution while reading this thread. Figured id post this for the next guy possibly.

When dealing with Laravel migration file from a package, I Ran into this issue.

My old value was

$table->increments('id');

My new

$table->integer('id')->autoIncrement();

How to concatenate two layers in keras?

Adding to the above-accepted answer so that it helps those who are using tensorflow 2.0 


import tensorflow as tf

# some data
c1 = tf.constant([[1, 1, 1], [2, 2, 2]], dtype=tf.float32)
c2 = tf.constant([[2, 2, 2], [3, 3, 3]], dtype=tf.float32)
c3 = tf.constant([[3, 3, 3], [4, 4, 4]], dtype=tf.float32)

# bake layers x1, x2, x3
x1 = tf.keras.layers.Dense(10)(c1)
x2 = tf.keras.layers.Dense(10)(c2)
x3 = tf.keras.layers.Dense(10)(c3)

# merged layer y1
y1 = tf.keras.layers.Concatenate(axis=1)([x1, x2])

# merged layer y2
y2 = tf.keras.layers.Concatenate(axis=1)([y1, x3])

# print info
print("-"*30)
print("x1", x1.shape, "x2", x2.shape, "x3", x3.shape)
print("y1", y1.shape)
print("y2", y2.shape)
print("-"*30)

Result:

------------------------------
x1 (2, 10) x2 (2, 10) x3 (2, 10)
y1 (2, 20)
y2 (2, 30)
------------------------------

How can I split a JavaScript string by white space or comma?

When I want to take into account extra characters like your commas (in my case each token may be entered with quotes), I'd do a string.replace() to change the other delimiters to blanks and then split on whitespace.

Implement Stack using Two Queues

 
queue<int> q1, q2;
int i = 0;

void push(int v) {
  if( q1.empty() && q2.empty() ) {
     q1.push(v);
     i = 0;
  }
  else {
     if( i == 0 ) {
        while( !q1.empty() ) q2.push(q1.pop());
        q1.push(v);
        i = 1-i;
     }
     else {
        while( !q2.empty() ) q1.push(q2.pop());
        q2.push(v);
        i = 1-i;
     }
  }
}

int pop() {
   if( q1.empty() && q2.empty() ) return -1;
   if( i == 1 ) {
      if( !q1.empty() )
           return q1.pop();
      else if( !q2.empty() )
           return q2.pop();
   }
   else {
      if( !q2.empty() )
           return q2.pop();
      else if( !q1.empty() )
           return q1.pop();
   }
}

Background color for Tk in Python

Its been updated so

root.configure(background="red")

is now:

root.configure(bg="red")

How do I generate random integers within a specific range in Java?

Generate a random number for the difference of min and max by using the nextint(n) method and then add min number to the result:

Random rn = new Random();
int result = rn.nextInt(max - min + 1) + min;
System.out.println(result);

Example: Communication between Activity and Service using Messaging

Note: You don't need to check if your service is running, CheckIfServiceIsRunning(), because bindService() will start it if it isn't running.

Also: if you rotate the phone you don't want it to bindService() again, because onCreate() will be called again. Be sure to define onConfigurationChanged() to prevent this.

Group a list of objects by an attribute

Using Java 8

import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import java.util.stream.Stream;

class Student {

    String stud_id;
    String stud_name;
    String stud_location;

    public String getStud_id() {
        return stud_id;
    }

    public String getStud_name() {
        return stud_name;
    }

    public String getStud_location() {
        return stud_location;
    }



    Student(String sid, String sname, String slocation) {

        this.stud_id = sid;
        this.stud_name = sname;
        this.stud_location = slocation;

    }
}

class Temp
{
    public static void main(String args[])
    {

        Stream<Student> studs = 
        Stream.of(new Student("1726", "John", "New York"),
                new Student("4321", "Max", "California"),
                new Student("2234", "Max", "Los Angeles"),
                new Student("7765", "Sam", "California"));
        Map<String, Map<Object, List<Student>>> map= studs.collect(Collectors.groupingBy(Student::getStud_name,Collectors.groupingBy(Student::getStud_location)));
                System.out.println(map);//print by name and then location
    }

}

The result will be:

{
    Max={
        Los Angeles=[Student@214c265e], 
        California=[Student@448139f0]
    }, 
    John={
        New York=[Student@7cca494b]
    }, 
    Sam={
        California=[Student@7ba4f24f]
    }
}

how to empty recyclebin through command prompt?

i use these commands in a batch file to empty recycle bin:

del /q /s %systemdrive%\$Recycle.bin\*
for /d %%x in (%systemdrive%\$Recycle.bin\*) do @rd /s /q "%%x"

How to remove backslash on json_encode() function?

As HungryDB said the easier way for do that is:

$mystring = json_encode($my_json,JSON_UNESCAPED_SLASHES);

Have a look at your php version because this parameter has been added in version 5.4.0

json_encode documentation

How do I create my own URL protocol? (e.g. so://...)

For most Microsoft products (Internet Explorer, Office, "open file" dialogs etc) you can register an application to be run when URI with appropriate prefix is opened. This is a part of more common explanation - how to implement your own protocol.

For Mozilla the explanation is here, Java - here.

How do I disable TextBox using JavaScript?

With the help of jquery it can be done as follows.

$("#color").prop('disabled', true);

How can I generate an ObjectId with mongoose?

I needed to generate mongodb ids on client side.

After digging into the mongodb source code i found they generate ObjectIDs using npm bson lib.

If ever you need only to generate an ObjectID without installing the whole mongodb / mongoose package, you can import the lighter bson library :

const bson = require('bson');
new bson.ObjectId(); // 5cabe64dcf0d4447fa60f5e2

Note: There is also an npm project named bson-objectid being even lighter

Get push notification while App in foreground iOS

As @Danial Martine said iOS won't show a notification banner/alert. That's by design. But if really have to do it then there is one way . I have also achieve this by same.

1.Download the parse frame work from Parse FrameWork

2.Import #import <Parse/Parse.h>

3.Add following code to your didReceiveRemoteNotification Method

 - (void)application:(UIApplication *)application
didReceiveRemoteNotification:(NSDictionary *)userInfo
{
    [PFPush handlePush:userInfo];
}

PFPush will take care how to handle the remote notification . If App is in foreground this shows the alert otherwise it shows the notification at the top.

How to show math equations in general github's markdown(not github's blog)

There is good solution for your problem - use TeXify github plugin (mentioned by Tom Hale answer - but I developed his answer in given link below) - more details about this github plugin and explanation why this is good approach you can find in that answer.

How to display HTML in TextView?

If you want to be able to configure it through xml without any modification in java code you may find this idea helpful. Simply you call init from constructor and set the text as html

public class HTMLTextView extends TextView {
    ... constructors calling init...
    private void init(){
       setText(Html.fromHtml(getText().toString()));
    }    
}

xml: 

<com.package.HTMLTextView
android:text="@string/about_item_1"/>

How do I make a list of data frames?

The other answers show you how to make a list of data.frames when you already have a bunch of data.frames, e.g., d1, d2, .... Having sequentially named data frames is a problem, and putting them in a list is a good fix, but best practice is to avoid having a bunch of data.frames not in a list in the first place.

The other answers give plenty of detail of how to assign data frames to list elements, access them, etc. We'll cover that a little here too, but the Main Point is to say don't wait until you have a bunch of a data.frames to add them to a list. Start with the list.

The rest of the this answer will cover some common cases where you might be tempted to create sequential variables, and show you how to go straight to lists. If you're new to lists in R, you might want to also read What's the difference between [[ and [ in accessing elements of a list?.

Lists from the start

Don't ever create d1 d2 d3, ..., dn in the first place. Create a list d with n elements.

Reading multiple files into a list of data frames

This is done pretty easily when reading in files. Maybe you've got files data1.csv, data2.csv, ... in a directory. Your goal is a list of data.frames called mydata. The first thing you need is a vector with all the file names. You can construct this with paste (e.g., my_files = paste0("data", 1:5, ".csv")), but it's probably easier to use list.files to grab all the appropriate files: my_files <- list.files(pattern = "\\.csv$"). You can use regular expressions to match the files, read more about regular expressions in other questions if you need help there. This way you can grab all CSV files even if they don't follow a nice naming scheme. Or you can use a fancier regex pattern if you need to pick certain CSV files out from a bunch of them.

At this point, most R beginners will use a for loop, and there's nothing wrong with that, it works just fine.

my_data <- list()
for (i in seq_along(my_files)) {
    my_data[[i]] <- read.csv(file = my_files[i])
}

A more R-like way to do it is with lapply, which is a shortcut for the above

my_data <- lapply(my_files, read.csv)

Of course, substitute other data import function for read.csv as appropriate. readr::read_csv or data.table::fread will be faster, or you may also need a different function for a different file type.

Either way, it's handy to name the list elements to match the files

names(my_data) <- gsub("\\.csv$", "", my_files)
# or, if you prefer the consistent syntax of stringr
names(my_data) <- stringr::str_replace(my_files, pattern = ".csv", replacement = "")

Splitting a data frame into a list of data frames

This is super-easy, the base function split() does it for you. You can split by a column (or columns) of the data, or by anything else you want

mt_list = split(mtcars, f = mtcars$cyl)
# This gives a list of three data frames, one for each value of cyl

This is also a nice way to break a data frame into pieces for cross-validation. Maybe you want to split mtcars into training, test, and validation pieces.

groups = sample(c("train", "test", "validate"),
                size = nrow(mtcars), replace = TRUE)
mt_split = split(mtcars, f = groups)
# and mt_split has appropriate names already!

Simulating a list of data frames

Maybe you're simulating data, something like this:

my_sim_data = data.frame(x = rnorm(50), y = rnorm(50))

But who does only one simulation? You want to do this 100 times, 1000 times, more! But you don't want 10,000 data frames in your workspace. Use replicate and put them in a list:

sim_list = replicate(n = 10,
                     expr = {data.frame(x = rnorm(50), y = rnorm(50))},
                     simplify = F)

In this case especially, you should also consider whether you really need separate data frames, or would a single data frame with a "group" column work just as well? Using data.table or dplyr it's quite easy to do things "by group" to a data frame.

I didn't put my data in a list :( I will next time, but what can I do now?

If they're an odd assortment (which is unusual), you can simply assign them:

mylist <- list()
mylist[[1]] <- mtcars
mylist[[2]] <- data.frame(a = rnorm(50), b = runif(50))
...

If you have data frames named in a pattern, e.g., df1, df2, df3, and you want them in a list, you can get them if you can write a regular expression to match the names. Something like

df_list = mget(ls(pattern = "df[0-9]"))
# this would match any object with "df" followed by a digit in its name
# you can test what objects will be got by just running the
ls(pattern = "df[0-9]")
# part and adjusting the pattern until it gets the right objects.

Generally, mget is used to get multiple objects and return them in a named list. Its counterpart get is used to get a single object and return it (not in a list).

Combining a list of data frames into a single data frame

A common task is combining a list of data frames into one big data frame. If you want to stack them on top of each other, you would use rbind for a pair of them, but for a list of data frames here are three good choices:

# base option - slower but not extra dependencies
big_data = do.call(what = rbind, args = df_list)

# data table and dplyr have nice functions for this that
#  - are much faster
#  - add id columns to identify the source
#  - fill in missing values if some data frames have more columns than others
# see their help pages for details
big_data = data.table::rbindlist(df_list)
big_data = dplyr::bind_rows(df_list)

(Similarly using cbind or dplyr::bind_cols for columns.)

To merge (join) a list of data frames, you can see these answers. Often, the idea is to use Reduce with merge (or some other joining function) to get them together.

Why put the data in a list?

Put similar data in lists because you want to do similar things to each data frame, and functions like lapply, sapply do.call, the purrr package, and the old plyr l*ply functions make it easy to do that. Examples of people easily doing things with lists are all over SO.

Even if you use a lowly for loop, it's much easier to loop over the elements of a list than it is to construct variable names with paste and access the objects with get. Easier to debug, too.

Think of scalability. If you really only need three variables, it's fine to use d1, d2, d3. But then if it turns out you really need 6, that's a lot more typing. And next time, when you need 10 or 20, you find yourself copying and pasting lines of code, maybe using find/replace to change d14 to d15, and you're thinking this isn't how programming should be. If you use a list, the difference between 3 cases, 30 cases, and 300 cases is at most one line of code---no change at all if your number of cases is automatically detected by, e.g., how many .csv files are in your directory.

You can name the elements of a list, in case you want to use something other than numeric indices to access your data frames (and you can use both, this isn't an XOR choice).

Overall, using lists will lead you to write cleaner, easier-to-read code, which will result in fewer bugs and less confusion.

How to get the path of running java program

Try this code:

final File f = new File(MyClass.class.getProtectionDomain().getCodeSource().getLocation().getPath());

replace 'MyClass' with your class containing the main method.

Alternatively you can also use 

System.getProperty("java.class.path")

Above mentioned System property provides

Path used to find directories and JAR archives containing class files. Elements of the class path are separated by a platform-specific character specified in the path.separator property.