Programs & Examples On #Date conversion

Conversion failed when converting date and/or time from character string in SQL SERVER 2008

If you're trying to insert in to last_accessed_on, which is a DateTime2, then your issue is with the fact that you are converting it to a varchar in a format that SQL doesn't understand.

If you modify your code to this, it should work, note the format of your date has been changed to: YYYY-MM-DD hh:mm:ss:

UPDATE  student_queues 
SET  Deleted=0, 
     last_accessed_by='raja', 
     last_accessed_on=CONVERT(datetime2,'2014-07-23 09:37:00')
WHERE std_id IN ('2144-384-11564') AND reject_details='REJECT'

Or if you want to use CAST, replace with:

CAST('2014-07-23 09:37:00.000' AS datetime2)

This is using the SQL ISO Date Format.

Go / golang time.Now().UnixNano() convert to milliseconds?

At https://github.com/golang/go/issues/44196 randall77 suggested

time.Now().Sub(time.Unix(0,0)).Milliseconds()

which exploits the fact that Go's time.Duration already have Milliseconds method.

sql server Get the FULL month name from a date

select datename(DAY,GETDATE()) +'-'+ datename(MONTH,GETDATE()) +'- '+ 
       datename(YEAR,GETDATE()) as 'yourcolumnname'

How to get the integer value of day of week

The correct way to get the integer value of an Enum such as DayOfWeek as a string is:

DayOfWeek.ToString("d")

Convert one date format into another in PHP

I know this is old, but, in running into a vendor that inconsistently uses 5 different date formats in their APIs (and test servers with a variety of PHP versions from the 5's through the latest 7's), I decided to write a universal converter that works with a myriad of PHP versions.

This converter will take virtually any input, including any standard datetime format (including with or without milliseconds) and any Epoch Time representation (including with or without milliseconds) and convert it to virtually any other format.

To call it:

$TheDateTimeIWant=convertAnyDateTome_toMyDateTime([thedateIhave],[theformatIwant]);

Sending null for the format will make the function return the datetime in Epoch/Unix Time. Otherwise, send any format string that date() supports, as well as with ".u" for milliseconds (I handle milliseconds as well, even though date() returns zeros).

Here's the code:

        <?php   
        function convertAnyDateTime_toMyDateTime($dttm,$dtFormat)
        {
            if (!isset($dttm))
            {
                return "";
            }
            $timepieces = array();
            if (is_numeric($dttm))
            {
                $rettime=$dttm;
            }
            else
            {
                $rettime=strtotime($dttm);
                if (strpos($dttm,".")>0 and strpos($dttm,"-",strpos($dttm,"."))>0)
                {
                    $rettime=$rettime.substr($dttm,strpos($dttm,"."),strpos($dttm,"-",strpos($dttm,"."))-strpos($dttm,"."));
                    $timepieces[1]="";
                }
                else if (strpos($dttm,".")>0 and strpos($dttm,"-",strpos($dttm,"."))==0)
                {               
                    preg_match('/([0-9]+)([^0-9]+)/',substr($dttm,strpos($dttm,"."))." ",$timepieces);
                    $rettime=$rettime.".".$timepieces[1];
                }
            }

            if (isset($dtFormat))
            {
                // RETURN as ANY date format sent
                if (strpos($dtFormat,".u")>0)       // Deal with milliseconds
                {
                    $rettime=date($dtFormat,$rettime);              
                    $rettime=substr($rettime,0,strripos($rettime,".")+1).$timepieces[1];                
                }
                else                                // NO milliseconds wanted
                {
                    $rettime=date($dtFormat,$rettime);
                }
            }
            else
            {
                // RETURN Epoch Time (do nothing, we already built Epoch Time)          
            }
            return $rettime;    
        }
    ?>

Here's some sample calls - you will note it also handles any time zone data (though as noted above, any non GMT time is returned in your time zone).

        $utctime1="2018-10-30T06:10:11.2185007-07:00";
        $utctime2="2018-10-30T06:10:11.2185007";
        $utctime3="2018-10-30T06:10:11.2185007 PDT";
        $utctime4="2018-10-30T13:10:11.2185007Z";
        $utctime5="2018-10-30T13:10:11Z";
        $dttm="10/30/2018 09:10:11 AM EST";

        echo "<pre>";
        echo "<b>Epoch Time to a standard format</b><br>";
        echo "<br>Epoch Tm: 1540905011    to STD DateTime     ----RESULT: ".convertAnyDateTime_toMyDateTime("1540905011","Y-m-d H:i:s")."<hr>";
        echo "<br>Epoch Tm: 1540905011          to UTC        ----RESULT: ".convertAnyDateTime_toMyDateTime("1540905011","c");
        echo "<br>Epoch Tm: 1540905011.2185007  to UTC        ----RESULT: ".convertAnyDateTime_toMyDateTime("1540905011.2185007","c")."<hr>";
        echo "<b>Returned as Epoch Time (the number of seconds that have elapsed since 00:00:00 Thursday, 1 January 1970, Coordinated Universal Time (UTC), minus leap seconds.)";
        echo "</b><br>";
        echo "<br>UTCTime1: ".$utctime1." ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime1,null);
        echo "<br>UTCTime2: ".$utctime2."       ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime2,null);
        echo "<br>UTCTime3: ".$utctime3."   ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime3,null);
        echo "<br>UTCTime4: ".$utctime4."      ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime4,null);
        echo "<br>UTCTime5: ".$utctime5."              ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime5,null);
        echo "<br>NO MILIS: ".$dttm."        ----RESULT: ".convertAnyDateTime_toMyDateTime($dttm,null);
        echo "<hr>";
        echo "<hr>";
        echo "<b>Returned as whatever datetime format one desires</b>";
        echo "<br>UTCTime1: ".$utctime1." ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime1,"Y-m-d H:i:s")."              Y-m-d H:i:s";
        echo "<br>UTCTime2: ".$utctime2."       ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime2,"Y-m-d H:i:s.u")."      Y-m-d H:i:s.u";
        echo "<br>UTCTime3: ".$utctime3."   ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime3,"Y-m-d H:i:s.u")."      Y-m-d H:i:s.u";
        echo "<p><b>Returned as ISO8601</b>";
        echo "<br>UTCTime3: ".$utctime3."   ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime3,"c")."        ISO8601";
        echo "</pre>";

Here's the output:

Epoch Tm: 1540905011                        ----RESULT: 2018-10-30 09:10:11

Epoch Tm: 1540905011          to UTC        ----RESULT: 2018-10-30T09:10:11-04:00
Epoch Tm: 1540905011.2185007  to UTC        ----RESULT: 2018-10-30T09:10:11-04:00
Returned as Epoch Time (the number of seconds that have elapsed since 00:00:00 Thursday, 1 January 1970, Coordinated Universal Time (UTC), minus leap seconds.)

UTCTime1: 2018-10-30T06:10:11.2185007-07:00 ----RESULT: 1540905011.2185007
UTCTime2: 2018-10-30T06:10:11.2185007       ----RESULT: 1540894211.2185007
UTCTime3: 2018-10-30T06:10:11.2185007 PDT   ----RESULT: 1540905011.2185007
UTCTime4: 2018-10-30T13:10:11.2185007Z      ----RESULT: 1540905011.2185007
UTCTime5: 2018-10-30T13:10:11Z              ----RESULT: 1540905011
NO MILIS: 10/30/2018 09:10:11 AM EST        ----RESULT: 1540908611
Returned as whatever datetime format one desires
UTCTime1: 2018-10-30T06:10:11.2185007-07:00 ----RESULT: 2018-10-30 09:10:11              Y-m-d H:i:s
UTCTime2: 2018-10-30T06:10:11.2185007       ----RESULT: 2018-10-30 06:10:11.2185007      Y-m-d H:i:s.u
UTCTime3: 2018-10-30T06:10:11.2185007 PDT   ----RESULT: 2018-10-30 09:10:11.2185007      Y-m-d H:i:s.u
Returned as ISO8601
UTCTime3: 2018-10-30T06:10:11.2185007 PDT   ----RESULT: 2018-10-30T09:10:11-04:00        ISO8601

The only thing not in this version is the ability to select the time zone you want the returned datetime to be in. Originally, I wrote this to change any datetime to Epoch Time, so, I didn't need time zone support. It's trivial to add though.

Converting unix time into date-time via excel

  • To convert the epoch(Unix-Time) to regular time like for the below timestamp

    Ex: 1517577336206

  • First convert the value with the following function like below

    =LEFT(A1,10) & "." & RIGHT(A1,3)

  • The output will be like below

    Ex: 1517577336.206

  • Now Add the formula like below

    =(((B1/60)/60)/24)+DATE(1970,1,1)

  • Now format the cell like below or required format(Custom format)

    m/d/yyyy h:mm:ss.000

Now example time comes like

2/2/2018 13:15:36.206

The three zeros are for milliseconds

How to convert a string Date to long millseconds

SimpleDateFormat formatter = new SimpleDateFormat("dd-MMM-yyyy");
Date date = (Date)formatter.parse("12-December-2012");
long mills = date.getTime();

Convert String XML fragment to Document Node in Java

...and if you're using purely XOM, something like this:

    String xml = "<fakeRoot>" + xml + "</fakeRoot>";
    Document doc = new Builder( false ).build( xml, null );
    Nodes children = doc.getRootElement().removeChildren();
    for( int ix = 0; ix < children.size(); ix++ ) {
        otherDocumentElement.appendChild( children.get( ix ) );
    }

XOM uses fakeRoot internally to do pretty much the same, so it should be safe, if not exactly elegant.

Javascript to stop HTML5 video playback on modal window close

When you close the video you just need to pause it.

$("#closeSimple").click(function() {
    $("div#simpleModal").removeClass("show");
    $("#videoContainer")[0].pause();
    return false;                   
});

<video id="videoContainer" width="320" height="240" src="Davis_5109iPadFig3.m4v" controls="controls"> </video>

Also, for reference, here's the Opera documentation for scripting video controls.

How to check file input size with jQuery?

You actually don't have access to filesystem (for example reading and writing local files), however, due to HTML5 File Api specification, there are some file properties that you do have access to, and the file size is one of them.

For the HTML below

<input type="file" id="myFile" />

try the following:

//binds to onchange event of your input field
$('#myFile').bind('change', function() {

  //this.files[0].size gets the size of your file.
  alert(this.files[0].size);

});

As it is a part of the HTML5 specification, it will only work for modern browsers (v10 required for IE) and I added here more details and links about other file information you should know: http://felipe.sabino.me/javascript/2012/01/30/javascipt-checking-the-file-size/


Old browsers support

Be aware that old browsers will return a null value for the previous this.files call, so accessing this.files[0] will raise an exception and you should check for File API support before using it

Going through a text file line by line in C

In addition to the other answers, on a recent C library (Posix 2008 compliant), you could use getline. See this answer (to a related question).

Compare DATETIME and DATE ignoring time portion

Use the CAST to the new DATE data type in SQL Server 2008 to compare just the date portion:

IF CAST(DateField1 AS DATE) = CAST(DateField2 AS DATE)

How to completely uninstall kubernetes

In my "Ubuntu 16.04", I use next steps to completely remove and clean Kubernetes (installed with "apt-get"):

kubeadm reset
sudo apt-get purge kubeadm kubectl kubelet kubernetes-cni kube*   
sudo apt-get autoremove  
sudo rm -rf ~/.kube

And restart the computer.

java.net.UnknownHostException: Unable to resolve host "<url>": No address associated with hostname and End of input at character 0 of

I encountered this error when running my Android app on my home WiFi, then trying to run it on different WiFi without closing my simulator.

Simply closing the simulator and re-launching the app worked for me!

How to add image to canvas

here is the sample code to draw image on canvas-

$("#selectedImage").change(function(e) {

var URL = window.URL;
var url = URL.createObjectURL(e.target.files[0]);
img.src = url;

img.onload = function() {
    var canvas = document.getElementById("myCanvas");
    var ctx = canvas.getContext("2d");        

    ctx.clearRect(0, 0, canvas.width, canvas.height);
    ctx.drawImage(img, 0, 0, 500, 500);
}});

In the above code selectedImage is an input control which can be used to browse image on system. For more details of sample code to draw image on canvas while maintaining the aspect ratio:

http://newapputil.blogspot.in/2016/09/show-image-on-canvas-html5.html

Sharing a URL with a query string on Twitter

I reference all the methods.

Encode the query twice is the fast solution.

const query = a=123&b=456;
const url = `https://example.com/test?${encodeURIComponent(encodeURIComponent(query),)}`;


const twitterSharingURL=`https://twitter.com/intent/tweet?&url=${url}`

Java - Including variables within strings?

you can use String format to include variables within strings

i use this code to include 2 variable in string:

String myString = String.format("this is my string %s %2d", variable1Name, variable2Name);

How to loop over a Class attributes in Java?

Simple way to iterate over class fields and obtain values from object:

 Class<?> c = obj.getClass();
 Field[] fields = c.getDeclaredFields();
 Map<String, Object> temp = new HashMap<String, Object>();

 for( Field field : fields ){
      try {
           temp.put(field.getName().toString(), field.get(obj));
      } catch (IllegalArgumentException e1) {
      } catch (IllegalAccessException e1) {
      }
 }

how to configure hibernate config file for sql server

Properties that are database specific are:

  • hibernate.connection.driver_class: JDBC driver class
  • hibernate.connection.url: JDBC URL
  • hibernate.connection.username: database user
  • hibernate.connection.password: database password
  • hibernate.dialect: The class name of a Hibernate org.hibernate.dialect.Dialect which allows Hibernate to generate SQL optimized for a particular relational database.

To change the database, you must:

  1. Provide an appropriate JDBC driver for the database on the class path,
  2. Change the JDBC properties (driver, url, user, password)
  3. Change the Dialect used by Hibernate to talk to the database

There are two drivers to connect to SQL Server; the open source jTDS and the Microsoft one. The driver class and the JDBC URL depend on which one you use.

With the jTDS driver

The driver class name is net.sourceforge.jtds.jdbc.Driver.

The URL format for sqlserver is:

 jdbc:jtds:sqlserver://<server>[:<port>][/<database>][;<property>=<value>[;...]]

So the Hibernate configuration would look like (note that you can skip the hibernate. prefix in the properties):

<hibernate-configuration>
  <session-factory>
    <property name="connection.driver_class">net.sourceforge.jtds.jdbc.Driver</property>
    <property name="connection.url">jdbc:jtds:sqlserver://<server>[:<port>][/<database>]</property>
    <property name="connection.username">sa</property>
    <property name="connection.password">lal</property>

    <property name="dialect">org.hibernate.dialect.SQLServerDialect</property>

    ...
  </session-factory>
</hibernate-configuration>

With Microsoft SQL Server JDBC 3.0:

The driver class name is com.microsoft.sqlserver.jdbc.SQLServerDriver.

The URL format is:

jdbc:sqlserver://[serverName[\instanceName][:portNumber]][;property=value[;property=value]]

So the Hibernate configuration would look like:

<hibernate-configuration>
  <session-factory>
    <property name="connection.driver_class">com.microsoft.sqlserver.jdbc.SQLServerDriver</property>
    <property name="connection.url">jdbc:sqlserver://[serverName[\instanceName][:portNumber]];databaseName=<databaseName></property>
    <property name="connection.username">sa</property>
    <property name="connection.password">lal</property>

    <property name="dialect">org.hibernate.dialect.SQLServerDialect</property>

    ...
  </session-factory>
</hibernate-configuration>

References

Break statement in javascript array map method

That's not possible using the built-in Array.prototype.map. However, you could use a simple for-loop instead, if you do not intend to map any values:

var hasValueLessThanTen = false;
for (var i = 0; i < myArray.length; i++) {
  if (myArray[i] < 10) {
    hasValueLessThanTen = true;
    break;
  }
}

Or, as suggested by @RobW, use Array.prototype.some to test if there exists at least one element that is less than 10. It will stop looping when some element that matches your function is found:

var hasValueLessThanTen = myArray.some(function (val) { 
  return val < 10;
});

How to change default Anaconda python environment

I got this when installing a library using anaconda. My version went from Python 3.* to 2.7 and a lot of my stuff stopped working. The best solution I found was to first see the most recent version available:

conda search python

Then update to the version you want:

conda install python=3.*.*

Source: http://chris35wills.github.io/conda_python_version/

Other helpful commands:

conda info
python --version

SQL Server JOIN missing NULL values

Try using additional condition in join:

SELECT Table1.Col1, Table1.Col2, Table1.Col3, Table2.Col4
FROM Table1 
INNER JOIN Table2
ON (Table1.Col1 = Table2.Col1 
    OR (Table1.Col1 IS NULL AND Table2.Col1 IS NULL)
   )

Java: Rotating Images

A simple way to do it without the use of such a complicated draw statement:

    //Make a backup so that we can reset our graphics object after using it.
    AffineTransform backup = g2d.getTransform();
    //rx is the x coordinate for rotation, ry is the y coordinate for rotation, and angle
    //is the angle to rotate the image. If you want to rotate around the center of an image,
    //use the image's center x and y coordinates for rx and ry.
    AffineTransform a = AffineTransform.getRotateInstance(angle, rx, ry);
    //Set our Graphics2D object to the transform
    g2d.setTransform(a);
    //Draw our image like normal
    g2d.drawImage(image, x, y, null);
    //Reset our graphics object so we can draw with it again.
    g2d.setTransform(backup);

How do I declare a namespace in JavaScript?

Sample:

var namespace = {};
namespace.module1 = (function(){

    var self = {};
    self.initialized = false;

    self.init = function(){
        setTimeout(self.onTimeout, 1000)
    };

    self.onTimeout = function(){
        alert('onTimeout')
        self.initialized = true;
    };

    self.init(); /* If it needs to auto-initialize, */
    /* You can also call 'namespace.module1.init();' from outside the module. */
    return self;
})()

You can optionally declare a local variable, same, like self and assign local.onTimeout if you want it to be private.

error: Your local changes to the following files would be overwritten by checkout

i had got the same error. Actually i tried to override the flutter Old SDK Package with new Updated Package. so that error occurred.

i opened flutter sdk directory with VS Code and cleaned the project

use this code in VSCode cmd

git clean -dxf

then use git pull

How to change navbar/container width? Bootstrap 3

Container widths will drop down to 940 pixels for viewports less than 992 pixels. If you really don’t want containers larger than 940 pixels wide, then go to the Bootstrap customize page, and set @container-lg-desktop to either @container-desktop or hard-coded 940px.

Easiest way to flip a boolean value?

If you know the values are 0 or 1, you could do flipval ^= 1.

How to prevent downloading images and video files from my website?

It also doesn't hurt to watermark your images with Photoshop or even in Lightroom 3 now. Make sure the watermark is clear and in a conspicuous place on your image. That way if it's downloaded, at least you get the advertising!

Creating a blurring overlay view

You can directly make your Background Blur using "Visual Effect View with Blur" and "Visual Effect View with Blur and Vibrancy".

All you have to do for making Blur Background in iOS Application is...

  1. Go and search for "Visual Effect View with Blur" in Object Library

Step 1 Image

  1. Drag the "Visual Effect View with Blur" in your Storyboard and setup it...

Step 2 Image

  1. Finally... You make your App Background Blur!

Application Layout before clicking on any Button!

Application View After Clicking on Button which makes the whole application background Blur!

What is the "__v" field in Mongoose

Well, I can't see Tony's solution...so I have to handle it myself...


If you don't need version_key, you can just:

var UserSchema = new mongoose.Schema({
    nickname: String,
    reg_time: {type: Date, default: Date.now}
}, {
    versionKey: false // You should be aware of the outcome after set to false
});

Setting the versionKey to false means the document is no longer versioned.

This is problematic if the document contains an array of subdocuments. One of the subdocuments could be deleted, reducing the size of the array. Later on, another operation could access the subdocument in the array at it's original position.

Since the array is now smaller, it may accidentally access the wrong subdocument in the array.

The versionKey solves this by associating the document with the a versionKey, used by mongoose internally to make sure it accesses the right collection version.

More information can be found at: http://aaronheckmann.blogspot.com/2012/06/mongoose-v3-part-1-versioning.html

PSQLException: current transaction is aborted, commands ignored until end of transaction block

I had the same issue but then realised there is a table with the same name in the database. After deleting that I was able to import the file.

How to display the string html contents into webbrowser control?

Instead of navigating to blank, you can do

webBrowser1.DocumentText="0";
webBrowser1.Document.OpenNew(true);
webBrowser1.Document.Write(theHTML);
webBrowser1.Refresh();

No need to wait for events or anything else. You can check the MSDN for OpenNew, while I have tested the initial DocumentText assignment in one of my projects and it works.

What exactly is node.js used for?

What can we build with NodeJS:

  • REST APIs and Backend Applications
  • Real-Time services (Chat, Games etc)
  • Blogs, CMS, Social Applications.
  • Utilities and Tools
  • Anything that is not CPU intensive.

How do you revert to a specific tag in Git?

You can use git checkout.

I tried the accepted solution but got an error, warning: refname '<tagname>' is ambiguous'

But as the answer states, tags do behave like a pointer to a commit, so as you would with a commit hash, you can just checkout the tag. The only difference is you preface it with tags/:

git checkout tags/<tagname>

Search all of Git history for a string?

Git can search diffs with the -S option (it's called pickaxe in the docs)

git log -S password

This will find any commit that added or removed the string password. Here a few options:

  • -p: will show the diffs. If you provide a file (-p file), it will generate a patch for you.
  • -G: looks for differences whose added or removed line matches the given regexp, as opposed to -S, which "looks for differences that introduce or remove an instance of string".
  • --all: searches over all branches and tags; alternatively, use --branches[=<pattern>] or --tags[=<pattern>]

How to embed a Google Drive folder in a website

Google Drive folders can be embedded and displayed in list and grid views:

List view

<iframe src="https://drive.google.com/embeddedfolderview?id=FOLDER-ID#list" style="width:100%; height:600px; border:0;"></iframe>


Grid view

<iframe src="https://drive.google.com/embeddedfolderview?id=FOLDER-ID#grid" style="width:100%; height:600px; border:0;"></iframe>



Q: What is a folder ID (FOLDER-ID) and how can I get it?

A: Go to Google Drive >> open the folder >> look at its URL in the address bar of your browser. For example:

Folder URL: https://drive.google.com/drive/folders/0B1iqp0kGPjWsNDg5NWFlZjEtN2IwZC00NmZiLWE3MjktYTE2ZjZjNTZiMDY2

Folder ID:
0B1iqp0kGPjWsNDg5NWFlZjEtN2IwZC00NmZiLWE3MjktYTE2ZjZjNTZiMDY2

Caveat with folders requiring permission

This technique works best for folders with public access. Folders that are shared only with certain Google accounts will cause trouble when you embed them this way. At the time of this edit, a message "You need permission" appears, with some buttons to help you "Request access" or "Switch accounts" (or possibly sign-in to a Google account). The Javascript in these buttons doesn't work properly inside an IFRAME in Chrome.

Read more at https://productforums.google.com/forum/#!msg/drive/GpVgCobPL2Y/_Xt7sMc1WzoJ

ORA-06508: PL/SQL: could not find program unit being called

I suspect you're only reporting the last error in a stack like this:

ORA-04068: existing state of packages has been discarded
ORA-04061: existing state of package body "schema.package" has been invalidated
ORA-04065: not executed, altered or dropped package body "schema.package"
ORA-06508: PL/SQL: could not find program unit being called: "schema.package"

If so, that's because your package is stateful:

The values of the variables, constants, and cursors that a package declares (in either its specification or body) comprise its package state. If a PL/SQL package declares at least one variable, constant, or cursor, then the package is stateful; otherwise, it is stateless.

When you recompile the state is lost:

If the body of an instantiated, stateful package is recompiled (either explicitly, with the "ALTER PACKAGE Statement", or implicitly), the next invocation of a subprogram in the package causes Oracle Database to discard the existing package state and raise the exception ORA-04068.

After PL/SQL raises the exception, a reference to the package causes Oracle Database to re-instantiate the package, which re-initializes it...

You can't avoid this if your package has state. I think it's fairly rare to really need a package to be stateful though, so you should revisit anything you have declared in the package, but outside a function or procedure, to see if it's really needed at that level. Since you're on 10g though, that includes constants, not just variables and cursors.

But the last paragraph from the quoted documentation means that the next time you reference the package in the same session, you won't get the error and it will work as normal (until you recompile again).

public static const in TypeScript

Just simply 'export' variable and 'import' in your class

export var GOOGLE_API_URL = 'https://www.googleapis.com/admin/directory/v1';

// default err string message
export var errStringMsg = 'Something went wrong';

Now use it as,

import appConstants = require('../core/AppSettings');
console.log(appConstants.errStringMsg);
console.log(appConstants.GOOGLE_API_URL);

Set default syntax to different filetype in Sublime Text 2

In the current version of Sublime Text 2 (Build: 2139), you can set the syntax for all files of a certain file extension using an option in the menu bar. Open a file with the extension you want to set a default for and navigate through the following menus: View -> Syntax -> Open all with current extension as... ->[your syntax choice].

Updated 2012-06-28: Recent builds of Sublime Text 2 (at least since Build 2181) have allowed the syntax to be set by clicking the current syntax type in the lower right corner of the window. This will open the syntax selection menu with the option to Open all with current extension as... at the top of the menu.

Updated 2016-04-19: As of now, this also works for Sublime Text 3.

Check number of arguments passed to a Bash script

If you're only interested in bailing if a particular argument is missing, Parameter Substitution is great:

#!/bin/bash
# usage-message.sh

: ${1?"Usage: $0 ARGUMENT"}
#  Script exits here if command-line parameter absent,
#+ with following error message.
#    usage-message.sh: 1: Usage: usage-message.sh ARGUMENT

How do I use DateTime.TryParse with a Nullable<DateTime>?

DateTime? d=null;
DateTime d2;
bool success = DateTime.TryParse("some date text", out d2);
if (success) d=d2;

(There might be more elegant solutions, but why don't you simply do something as above?)

Is there a CSS selector for the first direct child only?

What you posted literally means "Find any divs that are inside of section divs and are the first child of their parent." The sub contains one tag that matches that description.

It is unclear to me whether you want both children of the main div or not. If so, use this:

div.section > div

If you only want the header, use this:

div.section > div:first-child

Using the > changes the description to: "Find any divs that are the direct descendents of section divs" which is what you want.

Please note that all major browsers support this method, except IE6. If IE6 support is mission-critical, you will have to add classes to the child divs and use that, instead. Otherwise, it's not worth caring about.

For loop for HTMLCollection elements

You want to change it to

var list= document.getElementsByClassName("events");
console.log(list[0].id); //first console output
for (key in list){
    console.log(list[key].id); //second console output
}

Find which commit is currently checked out in Git

Use git show, which also shows you the commit message, and defaults to the current commit when given no arguments.

Java: Add elements to arraylist with FOR loop where element name has increasing number

That can't be done with a for-loop, unless you use the Reflection API. However, you can use Arrays.asList instead to accomplish the same:

List<Answer> answers = Arrays.asList(answer1, answer2, answer3);

How to add image that is on my computer to a site in css or html?

No, Not if your website is on a remote server, i.e not on localhost.

JSONP call showing "Uncaught SyntaxError: Unexpected token : "

Working fiddle:

http://jsfiddle.net/repjt/

$.ajax({
    url: 'https://api.flightstats.com/flex/schedules/rest/v1/jsonp/flight/AA/100/departing/2013/10/4?appId=19d57e69&appKey=e0ea60854c1205af43fd7b1203005d59',
    dataType: 'JSONP',
    jsonpCallback: 'callback',
    type: 'GET',
    success: function (data) {
        console.log(data);
    }
});

I had to manually set the callback to callback, since that's all the remote service seems to support. I also changed the url to specify that I wanted jsonp.

How to use QTimer

  1. It's good practice to give a parent to your QTimer to use Qt's memory management system.

  2. update() is a QWidget function - is that what you are trying to call or not? http://qt-project.org/doc/qt-4.8/qwidget.html#update.

  3. If number 2 does not apply, make sure that the function you are trying to trigger is declared as a slot in the header.

  4. Finally if none of these are your issue, it would be helpful to know if you are getting any run-time connect errors.

Pass a string parameter in an onclick function

This is a nice and neat way to send a value or object.

<!DOCTYPE html>
<html>
    <body>
        <h1  onclick="test('wow',this)">Click on this text!</h1>
        <script>
            var test = function(value,object) {
                object.innerHTML= value;
            };
        </script>
    </body>
</html>

Toggle input disabled attribute using jQuery

I guess to get full browser comparability disabled should set by the value disabled or get removed!
Here is a small plugin that I've just made:

(function($) {
    $.fn.toggleDisabled = function() {
        return this.each(function() {
            var $this = $(this);
            if ($this.attr('disabled')) $this.removeAttr('disabled');
            else $this.attr('disabled', 'disabled');
        });
    };
})(jQuery);

Example link.

EDIT: updated the example link/code to maintaining chainability!
EDIT 2:
Based on @lonesomeday comment, here's an enhanced version:

(function($) {
    $.fn.toggleDisabled = function(){
        return this.each(function(){
            this.disabled = !this.disabled;
        });
    };
})(jQuery);

The value violated the integrity constraints for the column

Delete empty rows from Excel after your last row of data!

Some times empty rows in Excel are still considered as data, therefore trying to import them in a table with one or more non nullable columns violates the constrains of the column.

Solution: select all of the empty rows on your sheet, even those after your last row of data, and click delete rows.

Obviously, if some of your data really does vioalte any of your table's constraints, then just fix your data to match the rules of your database..

change <audio> src with javascript

with jQuery:

 $("#playerSource").attr("src", "new_src");

    var audio = $("#player");      

    audio[0].pause();
    audio[0].load();//suspends and restores all audio element

    if (isAutoplay) 
        audio[0].play();

How to automate browsing using python?

I think the best solutions is the mix of requests and BeautifulSoup, I just wanted to update the question so it can be kept updated.

Entity Framework - Include Multiple Levels of Properties

EF Core: Using "ThenInclude" to load mutiple levels: For example:

var blogs = context.Blogs
    .Include(blog => blog.Posts)
        .ThenInclude(post => post.Author)
        .ThenInclude(author => author.Photo)
    .ToList();

ASP.NET Identity - HttpContext has no extension method for GetOwinContext

I had all the correct packages and usings, but had to built first before I could get GetOwinContext() to work.

HTML5 Local storage vs. Session storage

The main difference between localStorage and sessionStorage is that sessionStorage is unique per tab. If you close the tab the sessionStorage gets deleted, localStorage does not. Also you cannot communicate between tabs :)

Another subtle difference is that for example on Safari (8.0.3) localStorage has a limit of 2551 k characters but sessionStorage has unlimited storage

On Chrome (v43) both localStorage and sessionStorage are limited to 5101 k characters (no difference between normal / incognito mode)

On Firefox both localStorage and sessionStorage are limited to 5120 k characters (no difference between normal / private mode )

No difference in speed whatsoever :)

There's also a problem with Mobile Safari and Mobile Chrome, Private Mode Safari & Chrome have a maximum space of 0KB

setting the id attribute of an input element dynamically in IE: alternative for setAttribute method

Use jquery attr method. It works in all browsers.

var hiddenInput = document.createElement("input");
$(hiddenInput).attr({
    'id':'uniqueIdentifier',
    'type': 'hidden',
    'value': ID,
    'class': 'ListItem'
});

Or you could use folowing code:

var e = $('<input id = "uniqueIdentifier" type="hidden" value="' + ID + '" class="ListItem" />');

Java, How to specify absolute value and square roots

Use the java.lang.Math class, and specifically for absolute value and square root:, the abs() and sqrt() methods.

Programmatically add custom event in the iPhone Calendar

Swift 4.0 implementation :

use import in top of page by import EventKit

then

@IBAction func addtoCalendarClicked(sender: AnyObject) {

    let eventStore = EKEventStore()

    eventStore.requestAccess( to: EKEntityType.event, completion:{(granted, error) in

        if (granted) && (error == nil) {
            print("granted \(granted)")
            print("error \(error)")

            let event = EKEvent(eventStore: eventStore)

            event.title = "Event Title"
            event.startDate = Date()
            event.endDate = Date()
            event.notes = "Event Details Here"
            event.calendar = eventStore.defaultCalendarForNewEvents

            var event_id = ""
            do {
                try eventStore.save(event, span: .thisEvent)
                event_id = event.eventIdentifier
            }
            catch let error as NSError {
                print("json error: \(error.localizedDescription)")
            }

            if(event_id != ""){
                print("event added !")
            }
        }
    })
}

Which HTML Parser is the best?

The best I've seen so far is HtmlCleaner:

HtmlCleaner is open-source HTML parser written in Java. HTML found on Web is usually dirty, ill-formed and unsuitable for further processing. For any serious consumption of such documents, it is necessary to first clean up the mess and bring the order to tags, attributes and ordinary text. For the given HTML document, HtmlCleaner reorders individual elements and produces well-formed XML. By default, it follows similar rules that the most of web browsers use in order to create Document Object Model. However, user may provide custom tag and rule set for tag filtering and balancing.

With HtmlCleaner you can locate any element using XPath.

For other html parsers see this SO question.

How to word wrap text in HTML?

You can use a soft hyphen like so:

aaaaaaaaaaaaaaa&shy;aaaaaaaaaaaaaaa

This will appear as

aaaaaaaaaaaaaaa-
aaaaaaaaaaaaaaa

if the containing box isn't big enough, or as

aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

if it is.

Get number days in a specified month using JavaScript?

Date.prototype.monthDays= function(){
    var d= new Date(this.getFullYear(), this.getMonth()+1, 0);
    return d.getDate();
}

What is the preferred/idiomatic way to insert into a map?

If you want to insert element in std::map - use insert() function, and if you want to find element (by key) and assign some to it - use operator[].

For simplify inserting use boost::assign library, like this:

using namespace boost::assign;

// For inserting one element:

insert( function )( 0, 41 );

// For inserting several elements:

insert( function )( 0, 41 )( 0, 42 )( 0, 43 );

Editable 'Select' element

Thanks to @Arraxas's anwser, I customized the arrow and make the input element auto-adaptive to the select element, and it looks good on Chrome, Firefox of my Android mobile phone (set color:transparent for select and some color for option to hide text display of the select because the input and .combobox div:after cannot completely cover select).

_x000D_
_x000D_
/* https://stackoverflow.com/questions/13694271/modify-select-so-only-the-first-one-is-gray/41941056#41941056
select option:first-child, */
.combobox select, .combobox select option { color: #000000; }
.combobox select:invalid, .combobox select option[value=""] { color:grey; }

.combobox {position:absolute; left:80px; top:6px;}
.combobox>div { position:relative; font-size:1em; }
.combobox select {
    font-size:inherit; color:transparent;
    padding:0; -moz-appearance:none; -webkit-appearance:none; appearance:none;
    border:1px solid blueviolet;
}
.combobox input {
    position:absolute;top:1px;left:0px; text-overflow:ellipsis;
    box-sizing:border-box; padding:0px; margin:0px; height:calc(100% - 1px); width:calc(100% - 20px);
    border:1px solid blueviolet; border-right:none; border-top:none;
}
.combobox>div:after{
    position:absolute; top:0px; right:0px; height:100%; width:20px;
    box-sizing:border-box; content:"?"; border:1px solid blueviolet; pointer-events:none;
    display:flex; flex-direction:row; align-items:center; justify-content:center;
}
.combobox select:focus, .combobox input:focus {outline:none;}
_x000D_
<!-- mandatory benefits/social security/welfare -->
<div class="combobox"><div>
    <select id=MandatoryBenefits onchange="this.nextElementSibling.value=this.value" required>
        <option value="" selected>Select ...</option>
        <option value="Pension">Pension %</option>
        <option value="Medical">Medical %</option>
        <option value="Unemployment">Unemployment %</option>
        <option value="Injury">Injury %</option>
        <option value="Maternity">Maternity %</option>
        <option value="Serious Illness">Serious Illness %</option>
        <option value="Housing Fund">Housing Fund %</option>
    </select>
    <input type="text" value="" onchange="this.previousElementSibling.selectedIndex=0"
        oninput="this.previousElementSibling.options[0].value=this.value; this.previousElementSibling.options[0].innerHTML=this.value" />
</div></div>
_x000D_
_x000D_
_x000D_

online demo (@jsbin)

how to run two commands in sudo?

The above answers won't let you quote inside the quotes. This solution will:

sudo -su nobody umask 0000 \; mkdir -p "$targetdir"

Both the umask command and the mkdir-command runs in with the 'nobody' user.

How do I use 'git reset --hard HEAD' to revert to a previous commit?

WARNING: git clean -f will remove untracked files, meaning they're gone for good since they aren't stored in the repository. Make sure you really want to remove all untracked files before doing this.


Try this and see git clean -f.

git reset --hard will not remove untracked files, where as git-clean will remove any files from the tracked root directory that are not under Git tracking.

Alternatively, as @Paul Betts said, you can do this (beware though - that removes all ignored files too)

  • git clean -df
  • git clean -xdf CAUTION! This will also delete ignored files

Convert Java Object to JsonNode in Jackson

As of Jackson 1.6, you can use:

JsonNode node = mapper.valueToTree(map);

or

JsonNode node = mapper.convertValue(object, JsonNode.class);

Source: is there a way to serialize pojo's directly to treemodel?

How can I render HTML from another file in a React component?

If your template.html file is just HTML and not a React component, then you can't require it in the same way you would do with a JS file.

However, if you are using Browserify — there is a transform called stringify which will allow you to require non-js files as strings. Once you have added the transform, you will be able to require HTML files and they will export as though they were just strings.

Once you have required the HTML file, you'll have to inject the HTML string into your component, using the dangerouslySetInnerHTML prop.

var __html = require('./template.html');
var template = { __html: __html };

React.module.exports = React.createClass({
  render: function() {
    return(
      <div dangerouslySetInnerHTML={template} />
    );
  }
});

This goes against a lot of what React is about though. It would be more natural to create your templates as React components with JSX, rather than as regular HTML files.

The JSX syntax makes it trivially easy to express structured data, like HTML, especially when you use stateless function components.

If your template.html file looked something like this

<div class='foo'>
  <h1>Hello</h1>
  <p>Some paragraph text</p>
  <button>Click</button>
</div>

Then you could convert it instead to a JSX file that looked like this.

module.exports = function(props) {
  return (
    <div className='foo'>
      <h1>Hello</h1>
      <p>Some paragraph text</p>
      <button>Click</button>
    </div>
  );
};

Then you can require and use it without needing stringify.

var Template = require('./template');

module.exports = React.createClass({
  render: function() {
    var bar = 'baz';
    return(
      <Template foo={bar}/>
    );
  }
});

It maintains all of the structure of the original file, but leverages the flexibility of React's props model and allows for compile time syntax checking, unlike a regular HTML file.

how to run a winform from console application?

This worked for my needs...

Task mytask = Task.Run(() =>
{
    MyForm form = new MyForm();
    form.ShowDialog();
});

This starts the from in a new thread and does not release the thread until the form is closed. Task is in .Net 4 and later.

Unicode character as bullet for list-item in CSS

This topic may be old, but here's a quick fix ul {list-style:outside none square;} or ul {list-style:outside none disc;} , etc...

then add left padding to list element

ul li{line-height: 1.4;padding-bottom: 6px;}

How to get the top position of an element?

Try: $('#mytable').attr('offsetTop')

Class extending more than one class Java?

In Java multiple inheritance is not permitted. It was excluded from the language as a design decision, primarily to avoid circular dependencies.

Scenario1: As you have learned the following is not possible in Java:

public class Dog extends Animal, Canine{

}

Scenario 2: However the following is possible:

public class Canine extends Animal{

}

public class Dog extends Canine{

}

The difference in these two approaches is that in the second approach there is a clearly defined parent or super class, while in the first approach the super class is ambiguous.

Consider if both Animal and Canine had a method drink(). Under the first scenario which parent method would be called if we called Dog.drink()? Under the second scenario, we know calling Dog.drink() would call the Canine classes drink method as long as Dog had not overridden it.

python time + timedelta equivalent

The solution is in the link that you provided in your question:

datetime.combine(date.today(), time()) + timedelta(hours=1)

Full example:

from datetime import date, datetime, time, timedelta

dt = datetime.combine(date.today(), time(23, 55)) + timedelta(minutes=30)
print dt.time()

Output:

00:25:00

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

Use Linebreak:

<TextBlock>
        <Run Text="Line1"/>
        <LineBreak/>
        <Run Text="Line2" FontStyle="Italic" FontSize="9"/>
        <LineBreak/>
        <Run Text="Line3"/>
    </TextBlock>

Refer this: https://social.msdn.microsoft.com/Forums/vstudio/en-US/51a3ffe4-ec82-404a-9a99-6672f2a6842b/how-to-give-multiline-in-textblock?forum=wpf

Thanks,

RDV

Make div 100% Width of Browser Window

There are new units that you can use:

vw - viewport width

vh - viewport height

#neo_main_container1
{
   width: 100%; //fallback
   width: 100vw;
}

Help / MDN

Opera Mini does not support this, but you can use it in all other modern browsers.

CanIUse

enter image description here

How to lazy load images in ListView in Android

URLImageViewHelper is an amazing library that helps you to do that.

What is the http-header "X-XSS-Protection"?

This header is getting somehow deprecated. You can read more about it here - X-XSS-Protection

  • Chrome has removed their XSS Auditor
  • Firefox has not, and will not implement X-XSS-Protection
  • Edge has retired their XSS filter

This means that if you do not need to support legacy browsers, it is recommended that you use Content-Security-Policy without allowing unsafe-inline scripts instead.

change html input type by JS?

This is not supported by some browsers (IE if I recall), but it works in the rest:

document.getElementById("password-field").attributes["type"] = "password";

or

document.getElementById("password-field").attributes["type"] = "text";

Check if a file exists locally using JavaScript only

Since 'Kranu' helpfully advises 'The only interaction with the filesystem is with loading js files . . .', that suggests doing so with error checking would at least tell you if the file does not exist - which may be sufficient for your purposes?

From a local machine, you can check whether a file does not exist by attempting to load it as an external script then checking for an error. For example:

<span>File exists? </span>
<SCRIPT>
    function get_error(x){
        document.getElementsByTagName('span')[0].innerHTML+=x+" does not exist.";
    }
    url="   (put your path/file name in here)    ";
    url+="?"+new Date().getTime()+Math.floor(Math.random()*1000000);
    var el=document.createElement('script');
    el.id="123";
    el.onerror=function(){if(el.onerror)get_error(this.id)}
    el.src=url;
    document.body.appendChild(el);
</SCRIPT>

Some notes...

  • append some random data to the file name (url+="?"+new Date etc) so that the browser cache doesn't serve an old result.
  • set a unique element id (el.id=) if you're using this in a loop, so that the get_error function can reference the correct item.
  • setting the onerror (el.onerror=function) line is a tad complex because one needs it to call the get_error function AND pass el.id - if just a normal reference to the function (eg: el.onerror=get_error) were set, then no el.id parameter could be passed.
  • remember that this only checks if a file does not exist.

How to get a context in a recycler view adapter

Short answer:

Context context;

@Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
    super.onAttachedToRecyclerView(recyclerView);
    context = recyclerView.getContext();
}

Explanation why other answers are not great:

  1. Passing Context to the adapter is completely unnecessary, since RecyclerView you can access it from inside the class
  2. Obtaining Context at ViewHolder level means that you do it every time you bind or create a ViewHolder. You duplicate operations.
  3. I don't think you need to worry about any memory leak. If your adapter lingers outside your Activity lifespan (which would be weird) then you already have a leak.

Iterate through dictionary values?

If all your values are unique, you can make a reverse dictionary:

PIXO_reverse = {v: k for k, v in PIX0.items()}

Result:

>>> PIXO_reverse

{'320x240': 'QVGA', '640x480': 'VGA', '800x600': 'SVGA'}

Now you can use the same logic as before.

jQuery select all except first

My answer is focused to a extended case derived from the one exposed at top.

Suppose you have group of elements from which you want to hide the child elements except first. As an example:

<html>
  <div class='some-group'>
     <div class='child child-0'>visible#1</div>
     <div class='child child-1'>xx</div>
     <div class='child child-2'>yy</div>
  </div>
  <div class='some-group'>
     <div class='child child-0'>visible#2</div>
     <div class='child child-1'>aa</div>
     <div class='child child-2'>bb</div>
  </div>
</html>
  1. We want to hide all .child elements on every group. So this will not help because will hide all .child elements except visible#1:

    $('.child:not(:first)').hide();
    
  2. The solution (in this extended case) will be:

    $('.some-group').each(function(i,group){
        $(group).find('.child:not(:first)').hide();
    });
    

Where to place $PATH variable assertions in zsh?

I had similar problem (in bash terminal command was working correctly but zsh showed command not found error)

Solution:


just paste whatever you were earlier pasting in ~/.bashrc to:

~/.zshrc

How do I enable php to work with postgresql?

I have to add in httpd.conf this line (Windows):

LoadFile "C:/Program Files (x86)/PostgreSQL/8.3/bin/libpq.dll"

Add days to JavaScript Date

A solution designed for the pipeline operator:

const addDays = days => date => {
  const result = new Date(date);

  result.setDate(result.getDate() + days);

  return result;
};

Usage:

// Without the pipeline operator...
addDays(7)(new Date());

// And with the pipeline operator...
new Date() |> addDays(7);

If you need more functionality, I suggest looking into the date-fns library.

C++ "Access violation reading location" Error

Vertex *f=(findvertex(from));
if(!f) {
    cerr << "vertex not found" << endl;
    exit(1) // or return;
}

Because findVertex can return NULL if it can't find the vertex.

Otherwise this f->adj; is trying to do

NULL->adj;

Which causes access violation.

How do I obtain the frequencies of each value in an FFT?

Take a look at my answer here.

Answer to comment:

The FFT actually calculates the cross-correlation of the input signal with sine and cosine functions (basis functions) at a range of equally spaced frequencies. For a given FFT output, there is a corresponding frequency (F) as given by the answer I posted. The real part of the output sample is the cross-correlation of the input signal with cos(2*pi*F*t) and the imaginary part is the cross-correlation of the input signal with sin(2*pi*F*t). The reason the input signal is correlated with sin and cos functions is to account for phase differences between the input signal and basis functions.

By taking the magnitude of the complex FFT output, you get a measure of how well the input signal correlates with sinusoids at a set of frequencies regardless of the input signal phase. If you are just analyzing frequency content of a signal, you will almost always take the magnitude or magnitude squared of the complex output of the FFT.

c# why can't a nullable int be assigned null as a value

What Harry S says is exactly right, but

int? accom = (accomStr == "noval" ? null : (int?)Convert.ToInt32(accomStr));

would also do the trick. (We Resharper users can always spot each other in crowds...)

How to use aria-expanded="true" to change a css property

_x000D_
_x000D_
li a[aria-expanded="true"] span{_x000D_
    color: red;_x000D_
}
_x000D_
<li class="active">_x000D_
    <a href="#3a" class="btn btn-default btn-lg" data-toggle="tab" aria-expanded="true">_x000D_
        <span class="network-name">Google+</span>_x000D_
    </a>_x000D_
</li>_x000D_
<li class="active">_x000D_
    <a href="#3a" class="btn btn-default btn-lg" data-toggle="tab" aria-expanded="false">_x000D_
        <span class="network-name">Google+</span>_x000D_
    </a>_x000D_
</li>
_x000D_
_x000D_
_x000D_

_x000D_
_x000D_
li a[aria-expanded="true"]{_x000D_
    background: yellow;_x000D_
}
_x000D_
<li class="active">_x000D_
    <a href="#3a" class="btn btn-default btn-lg" data-toggle="tab" aria-expanded="true">_x000D_
        <span class="network-name">Google+</span>_x000D_
    </a>_x000D_
</li>_x000D_
<li class="active">_x000D_
    <a href="#3a" class="btn btn-default btn-lg" data-toggle="tab" aria-expanded="false">_x000D_
        <span class="network-name">Google+</span>_x000D_
    </a>_x000D_
</li>
_x000D_
_x000D_
_x000D_

Find and replace Android studio

I think the shortcut that you're looking for is:

Ctrl+Shift+R on Windows and Linux/Ubuntu

Cmd+Shift+R on Mac OS X

ref: source

Export a graph to .eps file with R

If you are using ggplot2 to generate a figure, then a ggsave(file="name.eps") will also work.

Make a link open a new window (not tab)

I know that its bit old Q but if u get here by searching a solution so i got a nice one via jquery

  jQuery('a[target^="_new"]').click(function() {
    var width = window.innerWidth * 0.66 ;
    // define the height in
    var height = width * window.innerHeight / window.innerWidth ;
    // Ratio the hight to the width as the user screen ratio
    window.open(this.href , 'newwindow', 'width=' + width + ', height=' + height + ', top=' + ((window.innerHeight - height) / 2) + ', left=' + ((window.innerWidth - width) / 2));

});

it will open all the <a target="_new"> in a new window

EDIT:

1st, I did some little changes in the original code now it open the new window perfectly followed the user screen ratio (for landscape desktops)

but, I would like to recommend you to use the following code that open the link in new tab if you in mobile (thanks to zvona answer in other question):

jQuery('a[target^="_new"]').click(function() {
    return openWindow(this.href);
}


function openWindow(url) {

    if (window.innerWidth <= 640) {
        // if width is smaller then 640px, create a temporary a elm that will open the link in new tab
        var a = document.createElement('a');
        a.setAttribute("href", url);
        a.setAttribute("target", "_blank");

        var dispatch = document.createEvent("HTMLEvents");
        dispatch.initEvent("click", true, true);

        a.dispatchEvent(dispatch);
    }
    else {
        var width = window.innerWidth * 0.66 ;
        // define the height in
        var height = width * window.innerHeight / window.innerWidth ;
        // Ratio the hight to the width as the user screen ratio
        window.open(url , 'newwindow', 'width=' + width + ', height=' + height + ', top=' + ((window.innerHeight - height) / 2) + ', left=' + ((window.innerWidth - width) / 2));
    }
    return false;
}

How to add button tint programmatically

The suggested answer here doesn't work properly on android 5.0 if your XML based color state list references themed attributes.. For instance, I have an xml color state list like so:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:color="?colorPrimary" android:state_enabled="true"/>
    <item android:alpha="0.12" android:color="?attr/colorOnSurface"/>
</selector>

Using this as my backgroundTint from xml works just fine on android 5.0 and everything else. However if I try to set this in code like this:

(Don't do this)

myButton.setSupportButtonTintList(ContextCompat.getColorStateList(myButton.getContext(), R.color.btn_tint_primary));

It actually doesn't matter if I pass the Activity or the button's context to ContextCompat.getColorStateList() method, neither will give me the proper color state list with respect to the theme the button is within. This is because using theme attributes in color state lists wasn't supported until api 23 and ContextCompat does not do anything special to resolve these. Instead you must use AppCompatResources.getColorStateList() which does its own resource parsing/theme attribute resolution on devices < API 23.

Instead, you must use this:

myButton.setSupportBackgroundTintList(AppCompatResources.getColorStateList(myButton.getContext(), R.color.btn_tint_primary));

TLDR: use AppCompatResources and not -ContextCompat- if you'll need resolved themed resources across all API versions of android.

For more information on the topic, see this article.

How to set default value to the input[type="date"]

A possible solution:

document.getElementById("yourDatePicker").valueAsDate = new Date();

Using Moment.js:

var today = moment().format('YYYY-MM-DD');
document.getElementById("datePicker").value = today;

bootstrap.min.js:6 Uncaught Error: Bootstrap dropdown require Popper.js

You need to install popperjs along with bootstrap to get rid of this error.Note that if you are using "bootstrap": "^4.4.1", and @popperjs/core v2.x combinations,bootstrap may not support popperjs version. So downgrade your version.

Option 1: npm install popper.js@^1.12.9 --save

and Add following script between jquery and bootstrap scripts.

"node_modules/popper.js/dist/umd/popper.min.js",

Option 2: Add following script tag to index.html

<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.11.0/umd/popper.min.js" integrity="sha384-b/U6ypiBEHpOf/4+1nzFpr53nxSS+GLCkfwBdFNTxtclqqenISfwAzpKaMNFNmj4" crossorigin="anonymous"></script

undefined reference to boost::system::system_category() when compiling

Linking with a library that defines the missing symbol (-lboost_system) is the obvious solution, but in the particular case of Boost.System, a misfeature in the original design makes it use boost::system::generic_category() and boost::system::system_category() needlessly. Compiling with the flag -DBOOST_SYSTEM_NO_DEPRECATED disables that code and lets a number of programs compile without requiring -lboost_system (that link is of course still needed if you explicitly use some of the library's features).

Starting from Boost 1.66 and this commit, this behavior is now the default, so hopefully fewer and fewer users should need this answer.

As noticed by @AndrewMarshall, an alternative is to define BOOST_ERROR_CODE_HEADER_ONLY which enables a header-only version of the code. This was discouraged by Boost as it can break some functionality. However, since 1.69, header-only seems to have become the default, supposedly making this question obsolete.

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

As Jake points out, TARGET_IPHONE_SIMULATOR is a subset of TARGET_OS_IPHONE.

Also, TARGET_OS_IPHONE is a subset of TARGET_OS_MAC.

So a better approach might be:

#ifdef _WIN64
   //define something for Windows (64-bit)
#elif _WIN32
   //define something for Windows (32-bit)
#elif __APPLE__
    #include "TargetConditionals.h"
    #if TARGET_OS_IPHONE && TARGET_IPHONE_SIMULATOR
        // define something for simulator   
    #elif TARGET_OS_IPHONE
        // define something for iphone  
    #else
        #define TARGET_OS_OSX 1
        // define something for OSX
    #endif
#elif __linux
    // linux
#elif __unix // all unices not caught above
    // Unix
#elif __posix
    // POSIX
#endif

MongoDB - Update objects in a document's array (nested updating)

We can use $set operator to update the nested array inside object filed update the value

db.getCollection('geolocations').update( 
   {
       "_id" : ObjectId("5bd3013ac714ea4959f80115"), 
       "geolocation.country" : "United States of America"
   }, 
   { $set: 
       {
           "geolocation.$.country" : "USA"
       } 
    }, 
   false,
   true
);

How do I write a Windows batch script to copy the newest file from a directory?

Windows shell, one liner:

FOR /F %%I IN ('DIR *.* /B /O:-D') DO COPY %%I <<NewDir>> & EXIT

How to delete a specific line in a file?

The issue with reading lines in first pass and making changes (deleting specific lines) in the second pass is that if you file sizes are huge, you will run out of RAM. Instead, a better approach is to read lines, one by one, and write them into a separate file, eliminating the ones you don't need. I have run this approach with files as big as 12-50 GB, and the RAM usage remains almost constant. Only CPU cycles show processing in progress.

Only numbers. Input number in React

After reading all the answers but none really working for numbers only with copy and paste I came up with this solution.

  • parseInt solution: fails as parseInt("2a") is valid;
  • onKeyup sulution: fails on copy and paste, backspace;
  • key.which solution: will probably fail on copy and paste;
  • type="number" solution: fails on long numbers as javascript converts 40817810000000023511 into 40817810000000023500 because it is 53 bit language
<input
    name="address.line1"
    value={values.address.line1}
    onChange={(event: any) => {
      if (isFinite(event.target.value)) {
      // UPDATE YOUR STATE (i am using formik)
      setFieldValue("address.line1", event.target.value);
    }
  }}
/>

Enable vertical scrolling on textarea

Here's your CSS

element{
  width: 200px;
  height: 300px;
  overflow-y: auto;
}

Can't install any packages in Node.js using "npm install"

Npm repository is currently down. See issue #2694 on npm github

EDIT:
To use a mirror in the meanwhile:

 npm set registry http://ec2-46-137-149-160.eu-west-1.compute.amazonaws.com

you can reset this later with:

 npm set registry https://registry.npmjs.org/

source

What is the difference between _tmain() and main() in C++?

_tmain is a macro that gets redefined depending on whether or not you compile with Unicode or ASCII. It is a Microsoft extension and isn't guaranteed to work on any other compilers.

The correct declaration is

 int _tmain(int argc, _TCHAR *argv[]) 

If the macro UNICODE is defined, that expands to

int wmain(int argc, wchar_t *argv[])

Otherwise it expands to

int main(int argc, char *argv[])

Your definition goes for a bit of each, and (if you have UNICODE defined) will expand to

 int wmain(int argc, char *argv[])

which is just plain wrong.

std::cout works with ASCII characters. You need std::wcout if you are using wide characters.

try something like this

#include <iostream>
#include <tchar.h>

#if defined(UNICODE)
    #define _tcout std::wcout
#else
    #define _tcout std::cout
#endif

int _tmain(int argc, _TCHAR *argv[]) 
{
   _tcout << _T("There are ") << argc << _T(" arguments:") << std::endl;

   // Loop through each argument and print its number and value
   for (int i=0; i<argc; i++)
      _tcout << i << _T(" ") << argv[i] << std::endl;

   return 0;
}

Or you could just decide in advance whether to use wide or narrow characters. :-)

Updated 12 Nov 2013:

Changed the traditional "TCHAR" to "_TCHAR" which seems to be the latest fashion. Both work fine.

End Update

Spring MVC: difference between <context:component-scan> and <annotation-driven /> tags?

<mvc:annotation-driven /> means that you can define spring beans dependencies without actually having to specify a bunch of elements in XML or implement an interface or extend a base class. For example @Repository to tell spring that a class is a Dao without having to extend JpaDaoSupport or some other subclass of DaoSupport. Similarly @Controller tells spring that the class specified contains methods that will handle Http requests without you having to implement the Controller interface or extend a subclass that implements the controller.

When spring starts up it reads its XML configuration file and looks for <bean elements within it if it sees something like <bean class="com.example.Foo" /> and Foo was marked up with @Controller it knows that the class is a controller and treats it as such. By default, Spring assumes that all the classes it should manage are explicitly defined in the beans.XML file.

Component scanning with <context:component-scan base-package="com.mycompany.maventestwebapp" /> is telling spring that it should search the classpath for all the classes under com.mycompany.maventestweapp and look at each class to see if it has a @Controller, or @Repository, or @Service, or @Component and if it does then Spring will register the class with the bean factory as if you had typed <bean class="..." /> in the XML configuration files.

In a typical spring MVC app you will find that there are two spring configuration files, a file that configures the application context usually started with the Spring context listener.

<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

And a Spring MVC configuration file usually started with the Spring dispatcher servlet. For example.

<servlet>
        <servlet-name>main</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>main</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

Spring has support for hierarchical bean factories, so in the case of the Spring MVC, the dispatcher servlet context is a child of the main application context. If the servlet context was asked for a bean called "abc" it will look in the servlet context first, if it does not find it there it will look in the parent context, which is the application context.

Common beans such as data sources, JPA configuration, business services are defined in the application context while MVC specific configuration goes not the configuration file associated with the servlet.

Hope this helps.

Eclipse hangs on loading workbench

I had this problem in Windows 7, this is what fixed it for me.

http://letsgetdugg.com/2009/04/19/recovering-a-corrupt-eclipse-workspace/

cd ~/Documents/workspace/.metalog/.plugins

rm -rf org.eclipse.core.resources

How to get the new value of an HTML input after a keypress has modified it?

Here is a table of the different events and the levels of browser support. You need to pick an event which is supported across at least all modern browsers.

As you will see from the table, the keypress and change event do not have uniform support whereas the keyup event does.

Also make sure you attach the event handler using a cross-browser-compatible method...

How to add border radius on table row

Not trying to take any credits here, all credit goes to @theazureshadow for his reply, but I personally had to adapt it for a table that has some <th> instead of <td> for it's first row's cells.

I'm just posting the modified version here in case some of you want to use @theazureshadow's solution, but like me, have some <th> in the first <tr>. The class "reportTable" only have to be applied to the table itself.:

table.reportTable {
    border-collapse: separate;
    border-spacing: 0;
}

table.reportTable td {
    border: solid gray 1px;
    border-style: solid none none solid;
    padding: 10px;
}

table.reportTable td:last-child {
    border-right: solid gray 1px;
}

table.reportTable tr:last-child td{
    border-bottom: solid gray 1px;
}

table.reportTable th{
    border: solid gray 1px;
    border-style: solid none none solid;
    padding: 10px;
}

table.reportTable th:last-child{
    border-right: solid gray 1px;
    border-top-right-radius: 10px;
}

table.reportTable th:first-child{
    border-top-left-radius: 10px;
}

table.reportTable tr:last-child td:first-child{
    border-bottom-left-radius: 10px;
}   

table.reportTable tr:last-child td:last-child{
    border-bottom-right-radius: 10px;
}

Feel free to adjust the paddings, radiuses, etc to fit your needs. Hope that helps people!

Cannot make Project Lombok work on Eclipse

You not only have to add lombok.jar to the libraries, but also install it by either double-clicking the lombok jar, or from the command line run java -jar lombok.jar. That will show you a nice installer screen. Select your Eclipse installation and install.

Afterwards, you can check if the installer has correctly modified your eclipse.ini:

-vmargs
...
-javaagent:lombok.jar
-Xbootclasspath/a:lombok.jar

If your Eclipse was already running, you have to Exit Eclipse and start it again. (File/Restart is not enough)

If you are starting Eclipse using a shortcut, make sure that either there are no command line arguments filled in, or manually add -javaagent:lombok.jar -Xbootclasspath/a:lombok.jar somewhere after -vmargs.

Recent editions of Lombok also add a line to the About Eclipse screen. If Lombok is active you can find a line like 'Lombok v0.11.6 "Dashing Kakapo" is installed. http://projectlombok.org/' just above the line of buttons.

If for some reason, usually related to customized eclipse builds, you need to use the full path, you can instruct the installer on the command line to do so:

java -Dlombok.installer.fullpath -jar lombok.jar

Basic HTML - how to set relative path to current folder?

<html>
    <head>
        <title>Page</title>
    </head>
    <body>
       <a href="./">Folder directory</a> 
    </body>
</html>

Is there a Java equivalent or methodology for the typedef keyword in C++?

Typedef allows items to be implicitly assigned to types they are not. Some people try to get around this with extensions; read here at IBM for an explanation of why this is a bad idea.

Edit: While strong type inference is a useful thing, I don't think (and hope we won't) see typedef rearing it's ugly head in managed languages (ever?).

Edit 2: In C#, you can use a using statement like this at the top of a source file. It's used so you don't have to do the second item shown. The only time you see the name change is when a scope introduces a name collision between two types. The renaming is limited to one file, outside of which every variable/parameter type which used it is known by its full name.

using Path = System.IO.Path;
using System.IO;

Routing with multiple Get methods in ASP.NET Web API

You might not need to make any change in the routing. Just add following four methods in your customersController.cs file:

public ActionResult Index()
{
}

public ActionResult currentMonth()
{
}

public ActionResult customerById(int id)
{
}


public ActionResult customerByUsername(string userName)
{
}

Put the relevant code in the method. With the default routing supplied, you should get appropriate action result from the controller based on the action and parameters for your given urls.

Modify your default route as:

routes.MapRoute(
    "Default", // Route name
    "{controller}/{action}/{id}", // URL with parameters
    new { controller = "Api", action = "Index", id = UrlParameter.Optional } // Parameter defaults
);

Why would someone use WHERE 1=1 AND <conditions> in a SQL clause?

where 1=0, This is done to check if the table exists. Don't know why 1=1 is used.

How do I create a multiline Python string with inline variables?

f-strings, also called “formatted string literals,” are string literals that have an f at the beginning; and curly braces containing expressions that will be replaced with their values.

f-strings are evaluated at runtime.

So your code can be re-written as:

string1="go"
string2="now"
string3="great"
print(f"""
I will {string1} there
I will go {string2}
{string3}
""")

And this will evaluate to:

I will go there
I will go now
great

You can learn more about it here.

Declaring variable workbook / Worksheet vba

Use Sheets rather than Sheet and activate them sequentially:

Sub kl()
    Dim wb As Workbook
    Dim ws As Worksheet
    Set wb = ActiveWorkbook
    Set ws = Sheets("Sheet1")
    wb.Activate
    ws.Select
End Sub

jQuery bind to Paste Event, how to get the content of the paste

On modern browsers it's easy: just use the input event along with the inputType attribute:

$(document).on('input', 'input, textarea', function(e){
  if (e.originalEvent.inputType == 'insertFromPaste') {
    alert($(this).val());
  }
});

https://codepen.io/anon/pen/jJOWxg

What does the keyword "transient" mean in Java?

Transient variables in Java are never serialized.

Authentication plugin 'caching_sha2_password' cannot be loaded

Open my sql command promt:

step 1

then enter mysql password

step 2

finally use:

ALTER USER 'username'@'ip_address' IDENTIFIED WITH mysql_native_password BY 'password';

refer:https://stackoverflow.com/a/49228443/6097074

Thanks.

How do I extract a substring from a string until the second space is encountered?

Use a regex: .

Match m = Regex.Match(text, @"(.+? .+?) ");
if (m.Success) {
    do_something_with(m.Groups[1].Value);
}

Insert current date/time using now() in a field using MySQL/PHP

NOW() normally works in SQL statements and returns the date and time. Check if your database field has the correct type (datetime). Otherwise, you can always use the PHP date() function and insert:

date('Y-m-d H:i:s')

But I wouldn't recommend this.

Copy or rsync command

Keep in mind that while transferring files internally on a machine i.e not network transfer, using the -z flag can have a massive difference in the time taken for the transfer.

Transfer within same machine

Case 1: With -z flag:
    TAR took: 9.48345208168
    Encryption took: 2.79352903366
    CP took = 5.07273387909
    Rsync took = 30.5113282204

Case 2: Without the -z flag:
    TAR took: 10.7535531521
    Encryption took: 3.0386879921
    CP took = 4.85565590858
    Rsync took = 4.94515299797

How to substring in jquery

Yes you can, although it relies on Javascript's inherent functionality and not the jQuery library.

http://www.w3schools.com/jsref/jsref_substr.asp The substr function will allow you to extract certain parts of the string.

Now, if you're looking for a specific string or character to use to find what part of the string to extract, you can make use of the indexOf function as well. http://www.w3schools.com/jsref/jsref_IndexOf.asp

The question is somewhat vague though; even just link text with 'name' will achieve the desired result. What's the criteria for getting your substring, exactly?

How to run Selenium WebDriver test cases in Chrome

You can use the below code to run test cases in Chrome using Selenium WebDriver:

import java.io.IOException;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;

public class ChromeTest {

    /**
     * @param args
     * @throws InterruptedException
     * @throws IOException
     */
    public static void main(String[] args) throws InterruptedException, IOException {
        // Telling the system where to find the Chrome driver
        System.setProperty(
                "webdriver.chrome.driver",
                "E:/chromedriver_win32/chromedriver.exe");

        WebDriver webDriver = new ChromeDriver();

        // Open google.com
        webDriver.navigate().to("http://www.google.com");

        String html = webDriver.getPageSource();

        // Printing result here.
        System.out.println(html);

        webDriver.close();
        webDriver.quit();
    }
}

How to convert a string of numbers to an array of numbers?

My 2 cents for golfers:

b="1,2,3,4".split`,`.map(x=>+x)

backquote is string litteral so we can omit the parenthesis (because of the nature of split function) but it is equivalent to split(','). The string is now an array, we just have to map each value with a function returning the integer of the string so x=>+x (which is even shorter than the Number function (5 chars instead of 6)) is equivalent to :

function(x){return parseInt(x,10)}// version from techfoobar
(x)=>{return parseInt(x)}         // lambda are shorter and parseInt default is 10
(x)=>{return +x}                  // diff. with parseInt in SO but + is better in this case
x=>+x                             // no multiple args, just 1 function call

I hope it is a bit more clear.

must appear in the GROUP BY clause or be used in an aggregate function

In Postgres, you can also use the special DISTINCT ON (expression) syntax:

SELECT DISTINCT ON (cname) 
    cname, wmname, avg
FROM 
    makerar 
ORDER BY 
    cname, avg DESC ;

Run script on mac prompt "Permission denied"

Check the permissions on your Ruby script (may not have execute permission), your theme file and directory (in case it can't read the theme or tries to create other themes in there), and the directory you're in when you run the script (in case it makes temporary files in the current directory rather then /tmp).

Any one of them could be causing you grief.

Converting a datetime string to timestamp in Javascript

For those of us using non-ISO standard date formats, like civilian vernacular 01/01/2001 (mm/dd/YYYY), including time in a 12hour date format with am/pm marks, the following function will return a valid Date object:

function convertDate(date) {

    // # valid js Date and time object format (YYYY-MM-DDTHH:MM:SS)
    var dateTimeParts = date.split(' ');

    // # this assumes time format has NO SPACE between time and am/pm marks.
    if (dateTimeParts[1].indexOf(' ') == -1 && dateTimeParts[2] === undefined) {

        var theTime = dateTimeParts[1];

        // # strip out all except numbers and colon
        var ampm = theTime.replace(/[0-9:]/g, '');

        // # strip out all except letters (for AM/PM)
        var time = theTime.replace(/[[^a-zA-Z]/g, '');

        if (ampm == 'pm') {

            time = time.split(':');

            // # if time is 12:00, don't add 12
            if (time[0] == 12) {
                time = parseInt(time[0]) + ':' + time[1] + ':00';
            } else {
                time = parseInt(time[0]) + 12 + ':' + time[1] + ':00';
            }

        } else { // if AM

            time = time.split(':');

            // # if AM is less than 10 o'clock, add leading zero
            if (time[0] < 10) {
                time = '0' + time[0] + ':' + time[1] + ':00';
            } else {
                time = time[0] + ':' + time[1] + ':00';
            }
        }
    }
    // # create a new date object from only the date part
    var dateObj = new Date(dateTimeParts[0]);

    // # add leading zero to date of the month if less than 10
    var dayOfMonth = (dateObj.getDate() < 10 ? ("0" + dateObj.getDate()) : dateObj.getDate());

    // # parse each date object part and put all parts together
    var yearMoDay = dateObj.getFullYear() + '-' + (dateObj.getMonth() + 1) + '-' + dayOfMonth;

    // # finally combine re-formatted date and re-formatted time!
    var date = new Date(yearMoDay + 'T' + time);

    return date;
}

Usage:

date = convertDate('11/15/2016 2:00pm');

How to negate 'isblank' function

If you're trying to just count how many of your cells in a range are not blank try this:

=COUNTA(range)

Example: (assume that it starts from A1 downwards):

---------    
Something 
---------
Something
---------

---------
Something
---------

---------
Something
---------

=COUNTA(A1:A6) returns 4 since there are two blank cells in there.

How to get the URL of the current page in C#

You may at times need to get different values from URL.

Below example shows different ways of extracting different parts of URL

EXAMPLE: (Sample URL)

http://localhost:60527/WebSite1test/Default2.aspx?QueryString1=1&QueryString2=2

CODE

Response.Write("<br/> " + HttpContext.Current.Request.Url.Host);
Response.Write("<br/> " + HttpContext.Current.Request.Url.Authority);
Response.Write("<br/> " + HttpContext.Current.Request.Url.Port);
Response.Write("<br/> " + HttpContext.Current.Request.Url.AbsolutePath);
Response.Write("<br/> " + HttpContext.Current.Request.ApplicationPath);
Response.Write("<br/> " + HttpContext.Current.Request.Url.AbsoluteUri);
Response.Write("<br/> " + HttpContext.Current.Request.Url.PathAndQuery);

OUTPUT

localhost
localhost:60527
60527
/WebSite1test/Default2.aspx
/WebSite1test
http://localhost:60527/WebSite1test/Default2.aspx?QueryString1=1&QueryString1=2
/WebSite1test/Default2.aspx?QueryString1=1&QueryString2=2

You can copy paste above sample code & run it in asp.net web form application with different URL.

I also recommend reading ASP.Net Routing in case you may use ASP Routing then you don't need to use traditional URL with query string.

http://msdn.microsoft.com/en-us/library/cc668201%28v=vs.100%29.aspx

Node.js Port 3000 already in use but it actually isn't?

For windows user, Just simple stop all processes of Node.js in Task Manager

Hope it will help

Please help me convert this script to a simple image slider

Problems only surface when I am I trying to give the first loaded content an active state

Does this mean that you want to add a class to the first button?

$('.o-links').click(function(e) {   // ... }).first().addClass('O_Nav_Current'); 

instead of using IDs for the slider's items and resetting html contents you can use classes and indexes:

CSS:

.image-area {     width: 100%;     height: auto;     display: none; }  .image-area:first-of-type {     display: block; } 

JavaScript:

var $slides = $('.image-area'),     $btns = $('a.o-links');  $btns.on('click', function (e) {     var i = $btns.removeClass('O_Nav_Current').index(this);     $(this).addClass('O_Nav_Current');      $slides.filter(':visible').fadeOut(1000, function () {         $slides.eq(i).fadeIn(1000);     });      e.preventDefault();  }).first().addClass('O_Nav_Current'); 

http://jsfiddle.net/RmF57/

Convert UTC to local time in Rails 3

There is actually a nice Gem called local_time by basecamp to do all of that on client side only, I believe:

https://github.com/basecamp/local_time

When should I use the new keyword in C++?

Method 1 (using new)

  • Allocates memory for the object on the free store (This is frequently the same thing as the heap)
  • Requires you to explicitly delete your object later. (If you don't delete it, you could create a memory leak)
  • Memory stays allocated until you delete it. (i.e. you could return an object that you created using new)
  • The example in the question will leak memory unless the pointer is deleted; and it should always be deleted, regardless of which control path is taken, or if exceptions are thrown.

Method 2 (not using new)

  • Allocates memory for the object on the stack (where all local variables go) There is generally less memory available for the stack; if you allocate too many objects, you risk stack overflow.
  • You won't need to delete it later.
  • Memory is no longer allocated when it goes out of scope. (i.e. you shouldn't return a pointer to an object on the stack)

As far as which one to use; you choose the method that works best for you, given the above constraints.

Some easy cases:

  • If you don't want to worry about calling delete, (and the potential to cause memory leaks) you shouldn't use new.
  • If you'd like to return a pointer to your object from a function, you must use new

Assigning strings to arrays of characters

To expand on Sparr's answer

Initialization and assignment are two distinct operations that happen to use the same operator ("=") here.

Think of it like this:

Imagine that there are 2 functions, called InitializeObject, and AssignObject. When the compiler sees thing = value, it looks at the context and calls one InitializeObject if you're making a new thing. If you're not, it instead calls AssignObject.

Normally this is fine as InitializeObject and AssignObject usually behave the same way. Except when dealing with char arrays (and a few other edge cases) in which case they behave differently. Why do this? Well that's a whole other post involving the stack vs the heap and so on and so forth.

PS: As an aside, thinking of it in this way will also help you understand copy constructors and other such things if you ever venture into C++

UnicodeDecodeError: 'utf8' codec can't decode bytes in position 3-6: invalid data

Paste this on your command line:

export LC_CTYPE="en_US.UTF-8" 

Unable to add window -- token null is not valid; is your activity running?

If you use another view make sure to use view.getContext() instead of this or getApplicationContext()

-bash: export: `=': not a valid identifier

Try to surround the path with quotes, and remove the spaces

export PYTHONPATH="/home/user/my_project":$PYTHONPATH

And don't forget to preserve previous content suffixing by :$PYTHONPATH (which is the value of the variable)

Execute the following command to check everything is configured correctly:

echo $PYTHONPATH

Getting pids from ps -ef |grep keyword

Try

ps -ef | grep "KEYWORD" | awk '{print $2}'

That command should give you the PID of the processes with KEYWORD in them. In this instance, awk is returning what is in the 2nd column from the output.

INSERT INTO...SELECT for all MySQL columns

More Examples & Detail

    INSERT INTO vendors (
     name, 
     phone, 
     addressLine1,
     addressLine2,
     city,
     state,
     postalCode,
     country,
     customer_id
 )
 SELECT 
     name,
     phone,
     addressLine1,
     addressLine2,
     city,
     state ,
     postalCode,
     country,
     customer_id
 FROM 
     customers;

Python: Get relative path from comparing two absolute paths

A write-up of jme's suggestion, using pathlib, in Python 3.

from pathlib import Path
parent = Path(r'/a/b')
son = Path(r'/a/b/c/d')            
?
if parent in son.parents or parent==son:
    print(son.relative_to(parent)) # returns Path object equivalent to 'c/d'

JSONException: Value of type java.lang.String cannot be converted to JSONObject

This is simple way (thanks Gson)

JsonParser parser = new JsonParser();
String retVal = parser.parse(param).getAsString();

https://gist.github.com/MustafaFerhan/25906d2be6ca109f61ce#file-evaluatejavascript-string-problem

Property 'value' does not exist on type 'Readonly<{}>'

If you don't want to pass interface state or props model you can try this

class App extends React.Component <any, any>

Neither BindingResult nor plain target object for bean name available as request attribute

I had a similar problem in IntelliJ IDEA. My code was 100% correct, but after starting the Tomcat, you receive an exception. java.lang.IllegalStateException: Neither BindingResult

I just removed and added again Tomcat configuration. And it worked for me.

A picture Tomcat configuration

enter image description here

How to pass query parameters with a routerLink

<a [routerLink]="['../']" [queryParams]="{name: 'ferret'}" [fragment]="nose">Ferret Nose</a>
foo://example.com:8042/over/there?name=ferret#nose
\_/   \______________/\_________/ \_________/ \__/
 |           |            |            |        |
scheme    authority      path        query   fragment

For more info - https://angular.io/guide/router#query-parameters-and-fragments

Terminating idle mysql connections

Manual cleanup:

You can KILL the processid.

mysql> show full processlist;
+---------+------------+-------------------+------+---------+-------+-------+-----------------------+
| Id      | User       | Host              | db   | Command | Time  | State | Info                  |
+---------+------------+-------------------+------+---------+-------+-------+-----------------------+
| 1193777 | TestUser12 | 192.168.1.11:3775 | www  | Sleep   | 25946 |       | NULL                  |
+---------+------------+-------------------+------+---------+-------+-------+-----------------------+

mysql> kill 1193777;

But:

  • the php application might report errors (or the webserver, check the error logs)
  • don't fix what is not broken - if you're not short on connections, just leave them be.

Automatic cleaner service ;)

Or you configure your mysql-server by setting a shorter timeout on wait_timeout and interactive_timeout

mysql> show variables like "%timeout%";
+--------------------------+-------+
| Variable_name            | Value |
+--------------------------+-------+
| connect_timeout          | 5     |
| delayed_insert_timeout   | 300   |
| innodb_lock_wait_timeout | 50    |
| interactive_timeout      | 28800 |
| net_read_timeout         | 30    |
| net_write_timeout        | 60    |
| slave_net_timeout        | 3600  |
| table_lock_wait_timeout  | 50    |
| wait_timeout             | 28800 |
+--------------------------+-------+
9 rows in set (0.00 sec)

Set with:

set global wait_timeout=3;
set global interactive_timeout=3;

(and also set in your configuration file, for when your server restarts)

But you're treating the symptoms instead of the underlying cause - why are the connections open? If the PHP script finished, shouldn't they close? Make sure your webserver is not using connection pooling...

Read a zipped file as a pandas DataFrame

For "zip" files, you can use import zipfile and your code will be working simply with these lines:

import zipfile
import pandas as pd
with zipfile.ZipFile("Crime_Incidents_in_2013.zip") as z:
   with z.open("Crime_Incidents_in_2013.csv") as f:
      train = pd.read_csv(f, header=0, delimiter="\t")
      print(train.head())    # print the first 5 rows

And the result will be:

X,Y,CCN,REPORT_DAT,SHIFT,METHOD,OFFENSE,BLOCK,XBLOCK,YBLOCK,WARD,ANC,DISTRICT,PSA,NEIGHBORHOOD_CLUSTER,BLOCK_GROUP,CENSUS_TRACT,VOTING_PRECINCT,XCOORD,YCOORD,LATITUDE,LONGITUDE,BID,START_DATE,END_DATE,OBJECTID
0  -77.054968548763071,38.899775938598317,0925135...                                                                                                                                                               
1  -76.967309569035052,38.872119553647011,1003352...                                                                                                                                                               
2  -76.996184958456539,38.927921847721443,1101010...                                                                                                                                                               
3  -76.943077541353617,38.883686046653935,1104551...                                                                                                                                                               
4  -76.939209158039446,38.892278093281632,1125028...

Failed to find target with hash string 'android-25'

You don't need to update anything. Just download the SDK for API 25 from Android SDK Manager or by launching Android standalone SDK manager. The error is for missing platform and not for missing tool.Android SDK Manager Android Studio 2.2.2

To show only file name without the entire directory path

Use the basename command:

basename /home/user/new/*.txt

Converting an int or String to a char array on Arduino

You can convert it to char* if you don't need a modifiable string by using:

(char*) yourString.c_str();

This would be very useful when you want to publish a String variable via MQTT in arduino.

How to declare Global Variables in Excel VBA to be visible across the Workbook

Your question is: are these not modules capable of declaring variables at global scope?

Answer: YES, they are "capable"

The only point is that references to global variables in ThisWorkbook or a Sheet module have to be fully qualified (i.e., referred to as ThisWorkbook.Global1, e.g.) References to global variables in a standard module have to be fully qualified only in case of ambiguity (e.g., if there is more than one standard module defining a variable with name Global1, and you mean to use it in a third module).

For instance, place in Sheet1 code

Public glob_sh1 As String

Sub test_sh1()
    Debug.Print (glob_mod)
    Debug.Print (ThisWorkbook.glob_this)
    Debug.Print (Sheet1.glob_sh1)
End Sub

place in ThisWorkbook code

Public glob_this As String

Sub test_this()
    Debug.Print (glob_mod)
    Debug.Print (ThisWorkbook.glob_this)
    Debug.Print (Sheet1.glob_sh1)
End Sub

and in a Standard Module code

Public glob_mod As String

Sub test_mod()
    glob_mod = "glob_mod"
    ThisWorkbook.glob_this = "glob_this"
    Sheet1.glob_sh1 = "glob_sh1"
    Debug.Print (glob_mod)
    Debug.Print (ThisWorkbook.glob_this)
    Debug.Print (Sheet1.glob_sh1)
End Sub

All three subs work fine.

PS1: This answer is based essentially on info from here. It is much worth reading (from the great Chip Pearson).

PS2: Your line Debug.Print ("Hello") will give you the compile error Invalid outside procedure.

PS3: You could (partly) check your code with Debug -> Compile VBAProject in the VB editor. All compile errors will pop.

PS4: Check also Put Excel-VBA code in module or sheet?.

PS5: You might be not able to declare a global variable in, say, Sheet1, and use it in code from other workbook (reading http://msdn.microsoft.com/en-us/library/office/gg264241%28v=office.15%29.aspx#sectionSection0; I did not test this point, so this issue is yet to be confirmed as such). But you do not mean to do that in your example, anyway.

PS6: There are several cases that lead to ambiguity in case of not fully qualifying global variables. You may tinker a little to find them. They are compile errors.

5.7.57 SMTP - Client was not authenticated to send anonymous mail during MAIL FROM error

You seem to be passing the From address as emailAddress, which is not a proper email address. For Office365 the From needs to be a real address on the Office365 system.

You can validate that if you hardcode your email address as the From and your Office 365 password.

Don't leave it there though of course.

How to find Oracle Service Name

Connect to the database with the "system" user, and execute the following command:

show parameter service_name 

Proper usage of .net MVC Html.CheckBoxFor

I was having a problem with ASP.NET MVC 5 where CheckBoxFor would not check my checkboxes on server-side validation failure even though my model clearly had the value set to true. My Razor markup/code looked like:

@Html.CheckBoxFor(model => model.MyBoolValue, new { @class = "mySpecialClass" } )

To get this to work, I had to change this to:

@{
    var checkboxAttributes = Model.MyBoolValue ?
        (object) new { @class = "mySpecialClass", @checked = "checked" } :
        (object) new { @class = "mySpecialClass" };
}
@Html.CheckBox("MyBoolValue", checkboxAttributes)

How to start and stop/pause setInterval?

The reason you're seeing this specific problem:

JSFiddle wraps your code in a function, so start() is not defined in the global scope.

enter image description here


Moral of the story: don't use inline event bindings. Use addEventListener/attachEvent.


Other notes:

Please don't pass strings to setTimeout and setInterval. It's eval in disguise.

Use a function instead, and get cozy with var and white space:

_x000D_
_x000D_
var input = document.getElementById("input"),
  add;

function start() {
  add = setInterval(function() {
    input.value++;
  }, 1000);
}

start();
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="number" id="input" />
<input type="button" onclick="clearInterval(add)" value="stop" />
<input type="button" onclick="start()" value="start" />
_x000D_
_x000D_
_x000D_

Unmarshaling nested JSON objects

This is an example of how to unmarshall JSON responses from the Safebrowsing v4 API sbserver proxy server: https://play.golang.org/p/4rGB5da0Lt

// this example shows how to unmarshall JSON requests from the Safebrowsing v4 sbserver
package main

import (
    "fmt"
    "log"
    "encoding/json"
)

// response from sbserver POST request
type Results struct {
    Matches []Match     
}

// nested within sbserver response
type Match struct {
    ThreatType string 
    PlatformType string 
    ThreatEntryType string 
    Threat struct {
        URL string
    }
}

func main() {
    fmt.Println("Hello, playground")

    // sample POST request
    //   curl -X POST -H 'Content-Type: application/json' 
    // -d '{"threatInfo": {"threatEntries": [{"url": "http://testsafebrowsing.appspot.com/apiv4/ANY_PLATFORM/MALWARE/URL/"}]}}' 
    // http://127.0.0.1:8080/v4/threatMatches:find

    // sample JSON response
    jsonResponse := `{"matches":[{"threatType":"MALWARE","platformType":"ANY_PLATFORM","threatEntryType":"URL","threat":{"url":"http://testsafebrowsing.appspot.com/apiv4/ANY_PLATFORM/MALWARE/URL/"}}]}`

    res := &Results{}
    err := json.Unmarshal([]byte(jsonResponse), res)
        if(err!=nil) {
            log.Fatal(err)
        }

    fmt.Printf("%v\n",res)
    fmt.Printf("\tThreat Type: %s\n",res.Matches[0].ThreatType)
    fmt.Printf("\tPlatform Type: %s\n",res.Matches[0].PlatformType)
    fmt.Printf("\tThreat Entry Type: %s\n",res.Matches[0].ThreatEntryType)
    fmt.Printf("\tURL: %s\n",res.Matches[0].Threat.URL)
}

ipynb import another ipynb file

Please make sure that you also add a __init__.py file in the package where all your other .ipynb files are located.

This is in addition to the nbviewer link that minrk and syi provided above.

I also had some similar problem and then I wrote the solution as well as a link to my public google drive folder which has a working example :)

My Stackoverflow post with step by step experimentation and Solution:

Jupyter Notebook: Import .ipynb file and access it's method in other .ipynb file giving error

Hope this will help others as well. Thanks all!

How can I use a Python script in the command line without cd-ing to its directory? Is it the PYTHONPATH?

With PYTHONPATH set as in your example, you should be able to do

python -m gmbx

-m option will make Python search for your module in paths Python usually searches modules in, including what you added to PYTHONPATH. When you run interpreter like python gmbx.py, it looks for particular file and PYTHONPATH does not apply.

How to remove components created with Angular-CLI

No As of now you can't do this by any command. You've to remove Manually from app.module.ts and app.routing.module.ts if you're using Angular 5

Combine hover and click functions (jQuery)?

  $("#target").on({
        hover: function(){
           //do on mouse hover
        },  
        click: function(){
            //do on mouse click
        }  
    });

react-router - pass props to handler component

This is the solution from Rajesh, without the inconvenient commented by yuji, and updated for React Router 4.

The code would be like this:

<Route path="comments" render={(props) => <Comments myProp="value" {...props}/>}/>

Note that I use render instead of component. The reason is to avoid undesired remounting. I also pass the props to that method, and I use the same props on the Comments component with the object spread operator (ES7 proposal).

Curl setting Content-Type incorrectly

I think you want to specify

-H "Content-Type:text/xml"

with a colon, not an equals.

How to make a Qt Widget grow with the window size?

You need to change the default layout type of top level QWidget object from Break layout type to other layout types (Vertical Layout, Horizontal Layout, Grid Layout, Form Layout). For example: enter image description here

To something like this:

enter image description here

Python-equivalent of short-form "if" in C++

My cryptic version...

a = ['123', '456'][b == True]

How to place the cursor (auto focus) in text box when a page gets loaded without javascript support?

Just add autofocus in first input or textarea.

<input type="text" name="name" id="xax" autofocus="autofocus" />

Is it possible to change the content HTML5 alert messages?

You can use customValidity

$(function(){     var elements = document.getElementsByTagName("input");     for (var i = 0; i < elements.length; i++) {         elements[i].oninvalid = function(e) {             e.target.setCustomValidity("This can't be left blank!");         };     } }); 

I think that will work on at least Chrome and FF, I'm not sure about other browsers

Why this line xmlns:android="http://schemas.android.com/apk/res/android" must be the first in the layout xml file?

xmlns:android This is start tag for define android namespace in Android. This is standerd convention define by android google developer. when you are using and layout default or custom, then must use this namespace.

Defines the Android namespace. This attribute should always be set to "http://schemas.android.com/apk/res/android".

From the <manifest> element documentation.

Converting .NET DateTime to JSON

You can try a 3rd party library like json.net There's documention on the project site. It does say it requires .net 3.5.

Otherwise there's another one called Nii.json which i believe is a port from java. I found a link to it on this blog

Casting interfaces for deserialization in JSON.NET

(Copied from this question)

In cases where I have not had control over the incoming JSON (and so cannot ensure that it includes a $type property) I have written a custom converter that just allows you to explicitly specify the concrete type:

public class Model
{
    [JsonConverter(typeof(ConcreteTypeConverter<Something>))]
    public ISomething TheThing { get; set; }
}

This just uses the default serializer implementation from Json.Net whilst explicitly specifying the concrete type.

An overview are available on this blog post. Source code is below:

public class ConcreteTypeConverter<TConcrete> : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        //assume we can convert to anything for now
        return true;
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        //explicitly specify the concrete type we want to create
        return serializer.Deserialize<TConcrete>(reader);
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        //use the default serialization - it works fine
        serializer.Serialize(writer, value);
    }
}

Conditional logic in AngularJS template

You can use ng-show on every div element in the loop. Is this what you've wanted: http://jsfiddle.net/pGwRu/2/ ?

<div class="from" ng-show="message.from">From: {{message.from.name}}</div>

How do you tell if a checkbox is selected in Selenium for Java?

public boolean getcheckboxvalue(String element)
    {   
        WebElement webElement=driver.findElement(By.xpath(element));
        return webElement.isSelected();
    }

Get current URL path in PHP

You want $_SERVER['REQUEST_URI']. From the docs:

'REQUEST_URI'

The URI which was given in order to access this page; for instance, '/index.html'.

What is the best way to compare floats for almost-equality in Python?

I found the following comparison helpful:

str(f1) == str(f2)

"element.dispatchEvent is not a function" js error caught in firebug of FF3.0

Change the following line

$(document).ready(function() {

To

jQuery.noConflict();
jQuery(document).ready(function($) {

Very Long If Statement in Python

According to PEP8, long lines should be placed in parentheses. When using parentheses, the lines can be broken up without using backslashes. You should also try to put the line break after boolean operators.

Further to this, if you're using a code style check such as pycodestyle, the next logical line needs to have different indentation to your code block.

For example:

if (abcdefghijklmnopqrstuvwxyz > some_other_long_identifier and
        here_is_another_long_identifier != and_finally_another_long_name):
    # ... your code here ...
    pass

Encoding URL query parameters in Java

Unfortunately, URLEncoder.encode() does not produce valid percent-encoding (as specified in RFC 3986).

URLEncoder.encode() encodes everything just fine, except space is encoded to "+". All the Java URI encoders that I could find only expose public methods to encode the query, fragment, path parts etc. - but don't expose the "raw" encoding. This is unfortunate as fragment and query are allowed to encode space to +, so we don't want to use them. Path is encoded properly but is "normalized" first so we can't use it for 'generic' encoding either.

Best solution I could come up with:

return URLEncoder.encode(raw, "UTF-8").replaceAll("\\+", "%20");

If replaceAll() is too slow for you, I guess the alternative is to roll your own encoder...

EDIT: I had this code in here first which doesn't encode "?", "&", "=" properly:

//don't use - doesn't properly encode "?", "&", "="
new URI(null, null, null, raw, null).toString().substring(1);

How can I convert a datetime object to milliseconds since epoch (unix time) in Python?

>>> import datetime
>>> # replace datetime.datetime.now() with your datetime object
>>> int(datetime.datetime.now().strftime("%s")) * 1000 
1312908481000

Or the help of the time module (and without date formatting):

>>> import datetime, time
>>> # replace datetime.datetime.now() with your datetime object
>>> time.mktime(datetime.datetime.now().timetuple()) * 1000
1312908681000.0

Answered with help from: http://pleac.sourceforge.net/pleac_python/datesandtimes.html

Documentation:

Getting the parameters of a running JVM

I am adding this new answer because as per JDK8 documentation jcmd is suggested approach now.

It is suggested to use the latest utility, jcmd instead of the previous jstack, jinfo, and jmap utilities for enhanced diagnostics and reduced performance overhead.

Below are commands to get your properties/flags you want.

jcmd pid VM.system_properties
jcmd pid VM.flags

We need pid, for this use jcmd -l, like below

username@users-Air:~/javacode$ jcmd -l 
11441 Test 
6294 Test 
29197 jdk.jcmd/sun.tools.jcmd.JCmd -l 

Now time to use these pids to get properties/flags you want

Command: jcmd 11441 VM.system_properties

11441:
#Tue Oct 17 12:44:50 IST 2017
gopherProxySet=false
awt.toolkit=sun.lwawt.macosx.LWCToolkit
file.encoding.pkg=sun.io
java.specification.version=9
sun.cpu.isalist=
sun.jnu.encoding=UTF-8
java.class.path=.
java.vm.vendor=Oracle Corporation
sun.arch.data.model=64
java.vendor.url=http\://java.oracle.com/
user.timezone=Asia/Kolkata
java.vm.specification.version=9
os.name=Mac OS X
sun.java.launcher=SUN_STANDARD
user.country=US
sun.boot.library.path=/Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home/lib
sun.java.command=Test
http.nonProxyHosts=local|*.local|169.254/16|*.169.254/16
jdk.debug=release
sun.cpu.endian=little
user.home=/Users/XXXX
user.language=en
java.specification.vendor=Oracle Corporation
java.home=/Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home
file.separator=/
java.vm.compressedOopsMode=Zero based
line.separator=\n
java.specification.name=Java Platform API Specification
java.vm.specification.vendor=Oracle Corporation
java.awt.graphicsenv=sun.awt.CGraphicsEnvironment
sun.management.compiler=HotSpot 64-Bit Tiered Compilers
ftp.nonProxyHosts=local|*.local|169.254/16|*.169.254/16
java.runtime.version=9+181
user.name=XXXX
path.separator=\:
os.version=10.12.6
java.runtime.name=Java(TM) SE Runtime Environment
file.encoding=UTF-8
java.vm.name=Java HotSpot(TM) 64-Bit Server VM
java.vendor.url.bug=http\://bugreport.java.com/bugreport/
java.io.tmpdir=/var/folders/dm/gd6lc90d0hg220lzw_m7krr00000gn/T/
java.version=9
user.dir=/Users/XXXX/javacode
os.arch=x86_64
java.vm.specification.name=Java Virtual Machine Specification
java.awt.printerjob=sun.lwawt.macosx.CPrinterJob
sun.os.patch.level=unknown
MyParam=2
java.library.path=/Users/XXXX/Library/Java/Extensions\:/Library/Java/Extensions\:/Network/Library/Java/Extensions\:/System/Library/Java/Extensions\:/usr/lib/java\:.
java.vm.info=mixed mode
java.vendor=Oracle Corporation
java.vm.version=9+181
sun.io.unicode.encoding=UnicodeBig
java.class.version=53.0
socksNonProxyHosts=local|*.local|169.254/16|*.169.254/16

Command : jcmd 11441 VM.flags output:

11441:
-XX:CICompilerCount=3 -XX:ConcGCThreads=1 -XX:G1ConcRefinementThreads=4 -XX:G1HeapRegionSize=1048576 -XX:InitialHeapSize=67108864 -XX:MarkStackSize=4194304 -XX:MaxHeapSize=1073741824 -XX:MaxNewSize=643825664 -XX:MinHeapDeltaBytes=1048576 -XX:NonNMethodCodeHeapSize=5830092 -XX:NonProfiledCodeHeapSize=122914074 -XX:ProfiledCodeHeapSize=122914074 -XX:ReservedCodeCacheSize=251658240 -XX:+SegmentedCodeCache -XX:-UseAOT -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseFastUnorderedTimeStamps -XX:+UseG1GC 

For more instructions of usages of jcmd, see my blog post

How to prevent line breaks in list items using CSS

display: inline-block; will prevent break between the words in a list item

 li {
    display: inline-block;
 }

Generating random numbers in Objective-C

For game dev use random() to generate randoms. Probably at least 5x faster than using arc4random(). Modulo bias is not an issue, especially for games, when generating randoms using the full range of random(). Be sure to seed first. Call srandomdev() in AppDelegate. Here's some helper functions:

static inline int random_range(int low, int high){ return (random()%(high-low+1))+low;}
static inline CGFloat frandom(){ return (CGFloat)random()/UINT32_C(0x7FFFFFFF);}
static inline CGFloat frandom_range(CGFloat low, CGFloat high){ return (high-low)*frandom()+low;}

How do I check if a variable is of a certain type (compare two types) in C?

This is crazily stupid, but if you use the code:

fprintf("%x", variable)

and you use the -Wall flag while compiling, then gcc will kick out a warning of that it expects an argument of 'unsigned int' while the argument is of type '____'. (If this warning doesn't appear, then your variable is of type 'unsigned int'.)

Best of luck!

Edit: As was brought up below, this only applies to compile time. Very helpful when trying to figure out why your pointers aren't behaving, but not very useful if needed during run time.

Best algorithm for detecting cycles in a directed graph

The way I do it is to do a Topological Sort, counting the number of vertices visited. If that number is less than the total number of vertices in the DAG, you have a cycle.

undefined reference to `std::ios_base::Init::Init()'

You can resolve this in several ways:

  • Use g++ in stead of gcc: g++ -g -o MatSim MatSim.cpp
  • Add -lstdc++: gcc -g -o MatSim MatSim.cpp -lstdc++
  • Replace <string.h> by <string>

This is a linker problem, not a compiler issue. The same problem is covered in the question iostream linker error – it explains what is going on.

Oracle: Import CSV file

SQL Loader helps load csv files into tables: SQL*Loader

If you want sqlplus only, then it gets a bit complicated. You need to locate your sqlloader script and csv file, then run the sqlldr command.

Append same text to every cell in a column in Excel

It's a simple "&" function.

=cell&"yourtexthere"

Example - your cell says Mickey, and you want Mickey Mouse. Mickey is in A2. In B2, type

=A2&" Mouse"

Then, copy and "paste special" for values.

B2 now reads "Mickey Mouse"

C# - How to get Program Files (x86) on Windows 64 bit

One-liner using the new method in .NET. Will always return x86 Program Files folder.

Environment.Is64BitOperatingSystem ? Environment.GetEnvironmentVariable("ProgramFiles(x86)") : Environment.GetEnvironmentVariable("ProgramFiles"))

SQL Server Convert Varchar to Datetime

You can have all the different styles to datetime conversion :

https://www.w3schools.com/sql/func_sqlserver_convert.asp

This has range of values :-

CONVERT(data_type(length),expression,style)

For style values,
Choose anyone you need like I needed 106.

Array[n] vs Array[10] - Initializing array with variable vs real number

In C++, variable length arrays are not legal. G++ allows this as an "extension" (because C allows it), so in G++ (without being -pedantic about following the C++ standard), you can do:

int n = 10;
double a[n]; // Legal in g++ (with extensions), illegal in proper C++

If you want a "variable length array" (better called a "dynamically sized array" in C++, since proper variable length arrays aren't allowed), you either have to dynamically allocate memory yourself:

int n = 10;
double* a = new double[n]; // Don't forget to delete [] a; when you're done!

Or, better yet, use a standard container:

int n = 10;
std::vector<double> a(n); // Don't forget to #include <vector>

If you still want a proper array, you can use a constant, not a variable, when creating it:

const int n = 10;
double a[n]; // now valid, since n isn't a variable (it's a compile time constant)

Similarly, if you want to get the size from a function in C++11, you can use a constexpr:

constexpr int n()
{
    return 10;
}

double a[n()]; // n() is a compile time constant expression

What exactly is \r in C language?

That is not always true; it only works in Windows.
For interacting with terminal in putty, Linux shell,... it will be used for returning the cursor to the beginning of line. following picture shows the usage of that:

Without '\r':

Data comes without '\r' to the putty terminal, it has just '\n'.
it means that data will be printed just in next line.

enter image description here

With '\r':

Data comes with '\r', i.e. string ends with '\r\n'. So the cursor in putty terminal not only will go to the next line but also at the beginning of line

enter image description here

Hiding an Excel worksheet with VBA

To hide from the UI, use Format > Sheet > Hide

To hide programatically, use the Visible property of the Worksheet object. If you do it programatically, you can set the sheet as "very hidden", which means it cannot be unhidden through the UI.

ActiveWorkbook.Sheets("Name").Visible = xlSheetVeryHidden 
' or xlSheetHidden or xlSheetVisible

You can also set the Visible property through the properties pane for the worksheet in the VBA IDE (ALT+F11).

How to create RecyclerView with multiple view type?

I firstly recommend you to read Hannes Dorfmann's great article about this topic.

When new view type comes, you have to edit your adapter and you have to handle so many mess things. Your adapter should be Open for extension but Closed for modification.

You may check this two project, they can give the idea about how to handle different ViewTypes in Adapter:

How to solve npm install throwing fsevents warning on non-MAC OS?

Switch to PNPM: https://pnpm.js.org/

The fsevents warnings are gone (on Linux).

Even the latest yarn (2.x) shows the warnings.

ASP.NET postback with JavaScript

Using __doPostBack directly is sooooo the 2000s. Anybody coding WebForms in 2018 uses GetPostBackEventReference

(More seriously though, adding this as an answer for completeness. Using the __doPostBack directly is bad practice (single underscore prefix typically indicates a private member and double indicates a more universal private member), though it probably won't change or become obsolete at this point. We have a fully supported mechanism in ClientScriptManager.GetPostBackEventReference.)

Assuming your btnRefresh is inside our UpdatePanel and causes a postback, you can use GetPostBackEventReference like this (inspiration):

function RefreshGrid() {
    <%= ClientScript.GetPostBackEventReference(btnRefresh, String.Empty) %>;
}

Rails 4 - passing variable to partial

Don't use locals in Rails 4.2+

In Rails 4.2 I had to remove the locals part and just use size: 30 instead. Otherwise, it wouldn't pass the local variable correctly.

For example, use this:

<%= render @users, size: 30 %>

Path.Combine absolute with relative path strings

Call Path.GetFullPath on the combined path http://msdn.microsoft.com/en-us/library/system.io.path.getfullpath.aspx

> Path.GetFullPath(Path.Combine(@"C:\blah\",@"..\bling"))
C:\bling

(I agree Path.Combine ought to do this by itself)

Fatal error: Call to undefined function mysqli_connect()

On Raspberry Pi I had to install php5 mysql extension.

apt-get install php5-mysql

After installing the client, the webserver should be restarted. In case you're using apache, the following should work:

sudo service apache2 restart

The service cannot be started, either because it is disabled or because it has no enabled devices associated with it

Oddly enough, the issue for me was I was trying to open 2012 SQL Server Integration Services on SSMS 2008 R2. When I opened the same in SSMS 2012, it connected right away.

Join String list elements with a delimiter in one step

Or Joiner from Google Guava.

Joiner joiner = Joiner.on("+");
String join = joiner.join(joinList);

Printing pointers in C

You can't change the value (i.e., address of) a static array. In technical terms, the lvalue of an array is the address of its first element. Hence s == &s. It's just a quirk of the language.

Running Internet Explorer 6, Internet Explorer 7, and Internet Explorer 8 on the same machine

This does not directly answer your question, but have you had a look at Litmus? We tend to use it mostly for testing HTML/CSS compatibility across multiple browsers (supported by Litmus).

Node.js - use of module.exports as a constructor

CommonJS modules allow two ways to define exported properties. In either case you are returning an Object/Function. Because functions are first class citizens in JavaScript they to can act just like Objects (technically they are Objects). That said your question about using the new keywords has a simple answer: Yes. I'll illustrate...

Module exports

You can either use the exports variable provided to attach properties to it. Once required in another module those assign properties become available. Or you can assign an object to the module.exports property. In either case what is returned by require() is a reference to the value of module.exports.

A pseudo-code example of how a module is defined:

var theModule = {
  exports: {}
};

(function(module, exports, require) {

  // Your module code goes here

})(theModule, theModule.exports, theRequireFunction);

In the example above module.exports and exports are the same object. The cool part is that you don't see any of that in your CommonJS modules as the whole system takes care of that for you all you need to know is there is a module object with an exports property and an exports variable that points to the same thing the module.exports does.

Require with constructors

Since you can attach a function directly to module.exports you can essentially return a function and like any function it could be managed as a constructor (That's in italics since the only difference between a function and a constructor in JavaScript is how you intend to use it. Technically there is no difference.)

So the following is perfectly good code and I personally encourage it:

// My module
function MyObject(bar) {
  this.bar = bar;
}

MyObject.prototype.foo = function foo() {
  console.log(this.bar);
};

module.exports = MyObject;

// In another module:
var MyObjectOrSomeCleverName = require("./my_object.js");
var my_obj_instance = new MyObjectOrSomeCleverName("foobar");
my_obj_instance.foo(); // => "foobar"

Require for non-constructors

Same thing goes for non-constructor like functions:

// My Module
exports.someFunction = function someFunction(msg) {
  console.log(msg);
}

// In another module
var MyModule = require("./my_module.js");
MyModule.someFunction("foobar"); // => "foobar"

R dplyr: Drop multiple columns

Another way is to mutate the undesired columns to NULL, this avoids the embedded parentheses :

head(iris,2) %>% mutate_at(drop.cols, ~NULL)
#   Petal.Length Petal.Width Species
# 1          1.4         0.2  setosa
# 2          1.4         0.2  setosa

Assign format of DateTime with data annotations?

Apply DataAnnotation like:

[DisplayFormat(DataFormatString = "{0:MMM dd, yyyy}")]

Iterate Multi-Dimensional Array with Nested Foreach Statement

Two ways:

  1. Define the array as a jagged array, and use nested foreachs.
  2. Define the array normally, and use foreach on the entire thing.

Example of #2:

int[,] arr = { { 1, 2 }, { 3, 4 } };
foreach(int a in arr)
    Console.Write(a);

Output will be 1234. ie. exactly the same as doing i from 0 to n, and j from 0 to n.