Programs & Examples On #Staging

Staging is the process of deploying to an intermediate, usually internal, repository so that deployed artifacts can be tested and later promoted to higher levels so that they can finally be release to public repositories

git add only modified changes and ignore untracked files

Not sure if this is a feature or a bug but this worked for us:

git commit '' -m "Message"

Note the empty file list ''. Git interprets this to commit all modified tracked files, even if they are not staged, and ignore untracked files.

How do I remove a single file from the staging area (undo git add)?

When you do git status, Git tells you how to unstage:

Changes to be committed: (use "git reset HEAD <file>..." to unstage).

So git reset HEAD <file> worked for me and the changes were un-touched.

Remove new lines from string and replace with one empty space

Many of these solutions didn't work for me. This did the trick though:-

$svgxml = preg_replace("/(*BSR_ANYCRLF)\R/",'',$svgxml);

Here is the reference:- PCRE and New Lines

Android Studio - debug keystore

It is at the same location: ~/.android/debug.keystore

How to join on multiple columns in Pyspark?

An alternative approach would be:

df1 = sqlContext.createDataFrame(
    [(1, "a", 2.0), (2, "b", 3.0), (3, "c", 3.0)],
    ("x1", "x2", "x3"))

df2 = sqlContext.createDataFrame(
    [(1, "f", -1.0), (2, "b", 0.0)], ("x1", "x2", "x4"))

df = df1.join(df2, ['x1','x2'])
df.show()

which outputs:

+---+---+---+---+
| x1| x2| x3| x4|
+---+---+---+---+
|  2|  b|3.0|0.0|
+---+---+---+---+

With the main advantage being that the columns on which the tables are joined are not duplicated in the output, reducing the risk of encountering errors such as org.apache.spark.sql.AnalysisException: Reference 'x1' is ambiguous, could be: x1#50L, x1#57L.


Whenever the columns in the two tables have different names, (let's say in the example above, df2 has the columns y1, y2 and y4), you could use the following syntax:

df = df1.join(df2.withColumnRenamed('y1','x1').withColumnRenamed('y2','x2'), ['x1','x2'])

PHP - Debugging Curl

To just get the info of a CURL request do this:

$response = curl_exec($ch);

$info = curl_getinfo($ch);
var_dump($info);

How do I create a HTTP Client Request with a cookie?

You can do that using Requestify, a very simple and cool HTTP client I wrote for nodeJS, it support easy use of cookies and it also supports caching.

To perform a request with a cookie attached just do the following:

var requestify = require('requestify');
requestify.post('http://google.com', {}, {
    cookies: {
        sessionCookie: 'session-cookie-data'   
    }
});

Base64 String throwing invalid character error

You say

The string is exactly what was written to the file (with the addition of a "\0" at the end, but I don't think that even does anything).

In fact, it does do something (it causes your code to throw a FormatException:"Invalid character in a Base-64 string") because the Convert.FromBase64String does not consider "\0" to be a valid Base64 character.

  byte[] data1 = Convert.FromBase64String("AAAA\0"); // Throws exception
  byte[] data2 = Convert.FromBase64String("AAAA");   // Works

Solution: Get rid of the zero termination. (Maybe call .Trim("\0"))

Notes:

The MSDN docs for Convert.FromBase64String say it will throw a FormatException when

The length of s, ignoring white space characters, is not zero or a multiple of 4.

-or-

The format of s is invalid. s contains a non-base 64 character, more than two padding characters, or a non-white space character among the padding characters.

and that

The base 64 digits in ascending order from zero are the uppercase characters 'A' to 'Z', lowercase characters 'a' to 'z', numerals '0' to '9', and the symbols '+' and '/'.

How to implement a read only property

You can do this:

public int Property { get { ... } private set { ... } }

onchange equivalent in angular2

You can use:

<input (input)="saverange()>

Read url to string in few lines of java code

If you have the input stream (see Joe's answer) also consider ioutils.toString( inputstream ).

http://commons.apache.org/io/api-1.4/org/apache/commons/io/IOUtils.html#toString(java.io.InputStream)

Vue.js—Difference between v-model and v-bind

v-model
it is two way data binding, it is used to bind html input element when you change input value then bounded data will be change.

v-model is used only for HTML input elements

ex: <input type="text" v-model="name" > 

v-bind
it is one way data binding,means you can only bind data to input element but can't change bounded data changing input element. v-bind is used to bind html attribute
ex:
<input type="text" v-bind:class="abc" v-bind:value="">

<a v-bind:href="home/abc" > click me </a>

MySQL - How to increase varchar size of an existing column in a database without breaking existing data?

use this syntax: alter table table_name modify column col_name varchar (10000);

java.lang.NoClassDefFoundError: org/hamcrest/SelfDescribing

I had the same problem, the solution is to add in build path/plugin the jar org.hamcrest.core_1xx, you can find it in eclipse/plugins.

How to find the highest value of a column in a data frame in R?

max(may$Ozone, na.rm = TRUE)

Without $Ozone it will filter in the whole data frame, this can be learned in the swirl library.

I'm studying this course on Coursera too ~

Get Root Directory Path of a PHP project

Summary

This example assumes you always know where the apache root folder is '/var/www/' and you are trying to find the next folder path (e.g. '/var/www/my_website_folder'). Also this works from a script or the web browser which is why there is additional code.

Code PHP7

function getHtmlRootFolder(string $root = '/var/www/') {

    // -- try to use DOCUMENT_ROOT first --
    $ret = str_replace(' ', '', $_SERVER['DOCUMENT_ROOT']);
    $ret = rtrim($ret, '/') . '/';

    // -- if doesn't contain root path, find using this file's loc. path --
    if (!preg_match("#".$root."#", $ret)) {
      $root = rtrim($root, '/') . '/';
      $root_arr = explode("/", $root);
      $pwd_arr = explode("/", getcwd());
      $ret = $root . $pwd_arr[count($root_arr) - 1];
    }

    return (preg_match("#".$root."#", $ret)) ? rtrim($ret, '/') . '/' : null;
}

Example

echo getHtmlRootFolder();

Output:

/var/www/somedir/

Details:

Basically first tries to get DOCUMENT_ROOT if it contains '/var/www/' then use it, else get the current dir (which much exist inside the project) and gets the next path value based on count of the $root path. Note: added rtrim statements to ensure the path returns ending with a '/' in all cases . It doesn't check for it requiring to be larger than /var/www/ it can also return /var/www/ as a possible response.

Shortcut for echo "<pre>";print_r($myarray);echo "</pre>";

You can create Shortcut key in Sublime Text Editor using Preferences -> Key Bindings

Now add below code on right-side of Key Bindings within square bracket []

{ 
    "keys": ["ctrl+shift+c"],
    "command": "insert_snippet",
    "args": { "contents": "echo \"<pre>\";\nprint_r(${0:\\$variable_to_debug});\necho \"</pre>\";\ndie();\n" }
}

Enjoy your ctrl+shift+c shortcut as a Pretty Print of PHP.

Set the table column width constant regardless of the amount of text in its cells?

See: http://www.html5-tutorials.org/tables/changing-column-width/

After the table tag, use the col element. you don't need a closing tag.

For example, if you had three columns:

<table>
  <colgroup>
    <col style="width:40%">
    <col style="width:30%">
    <col style="width:30%">
  </colgroup>  
  <tbody>
    ...
  </tbody>
</table>

wildcard * in CSS for classes

If you don't need the unique identifier for further styling of the divs and are using HTML5 you could try and go with custom Data Attributes. Read on here or try a google search for HTML5 Custom Data Attributes

How to make external HTTP requests with Node.js

You can use the built-in http module to do an http.request().

However if you want to simplify the API you can use a module such as superagent

How to get index in Handlebars each helper?

In the newer versions of Handlebars index (or key in the case of object iteration) is provided by default with the standard each helper.


snippet from : https://github.com/wycats/handlebars.js/issues/250#issuecomment-9514811

The index of the current array item has been available for some time now via @index:

{{#each array}}
    {{@index}}: {{this}}
{{/each}}

For object iteration, use @key instead:

{{#each object}}
    {{@key}}: {{this}}
{{/each}} 

How to set background color of view transparent in React Native

You should be aware of the current conflicts that exists with iOS and RGBA backgrounds.

Summary: public React Native currently exposes the iOS layer shadow properties more-or-less directly, however there are a number of problems with this:

1) Performance when using these properties is poor by default. That's because iOS calculates the shadow by getting the exact pixel mask of the view, including any tranlucent content, and all of its subviews, which is very CPU and GPU-intensive. 2) The iOS shadow properties do not match the syntax or semantics of the CSS box-shadow standard, and are unlikely to be possible to implement on Android. 3) We don't expose the layer.shadowPath property, which is crucial to getting good performance out of layer shadows.

This diff solves problem number 1) by implementing a default shadowPath that matches the view border for views with an opaque background. This improves the performance of shadows by optimizing for the common usage case. I've also reinstated background color propagation for views which have shadow props - this should help ensure that this best-case scenario occurs more often.

For views with an explicit transparent background, the shadow will continue to work as it did before ( shadowPath will be left unset, and the shadow will be derived exactly from the pixels of the view and its subviews). This is the worst-case path for performance, however, so you should avoid it unless absolutely necessary. Support for this may be disabled by default in future, or dropped altogether.

For translucent images, it is suggested that you bake the shadow into the image itself, or use another mechanism to pre-generate the shadow. For text shadows, you should use the textShadow properties, which work cross-platform and have much better performance.

Problem number 2) will be solved in a future diff, possibly by renaming the iOS shadowXXX properties to boxShadowXXX, and changing the syntax and semantics to match the CSS standards.

Problem number 3) is now mostly moot, since we generate the shadowPath automatically. In future, we may provide an iOS-specific prop to set the path explicitly if there's a demand for more precise control of the shadow.

Reviewed By: weicool

Commit: https://github.com/facebook/react-native/commit/e4c53c28aea7e067e48f5c8c0100c7cafc031b06

WAMP error: Forbidden You don't have permission to access /phpmyadmin/ on this server

Even I faced the same issue with my domain. If I gave an IP address it was working. But with a domain name it was not.

Then I checked my DNS A record. The domain had multiple entries with different IP addresses assigned. I removed all the wrong values, and it worked. Just one more check list if anyone faces a similar issue.

How to customise file type to syntax associations in Sublime Text?

There is a quick method to set the syntax: Ctrl+Shift+P,then type in the input box

ss + (which type you want set)

eg: ss html +Enter

and ss means "set syntax"

it is really quicker than check in the menu's checkbox.

Disable and enable buttons in C#

Change this

button2.Enabled == true

to

button2.Enabled = true;

C# : Out of Memory exception

My Development Team resolved this situation:

We added the following Post-Build script into the .exe project and compiled again, setting the target to x86 and increasing by 1.5 gb and also x64 Platform target increasing memory using 3.2 gb. Our application is 32 bit.

Related URLs:

Script:

if exist "$(DevEnvDir)..\tools\vsvars32.bat" (
    call "$(DevEnvDir)..\tools\vsvars32.bat"
    editbin /largeaddressaware "$(TargetPath)"
)

Quickest way to convert XML to JSON in Java

The only problem with JSON in Java is that if your XML has a single child, but is an array, it will convert it to an object instead of an array. This can cause problems if you dynamically always convert from XML to JSON, where if your example XML has only one element, you return an object, but if it has 2+, you return an array, which can cause parsing issues for people using the JSON.

Infoscoop's XML2JSON class has a way of tagging elements that are arrays before doing the conversion, so that arrays can be properly mapped, even if there is only one child in the XML.

Here is an example of using it (in a slightly different language, but you can also see how arrays is used from the nodelist2json() method of the XML2JSON link).

How to run an .ipynb Jupyter Notebook from terminal?

nbconvert allows you to run notebooks with the --execute flag:

jupyter nbconvert --execute <notebook>

If you want to run a notebook and produce a new notebook, you can add --to notebook:

jupyter nbconvert --execute --to notebook <notebook>

Or if you want to replace the existing notebook with the new output:

jupyter nbconvert --execute --to notebook --inplace <notebook>

Since that's a really long command, you can use an alias:

alias nbx="jupyter nbconvert --execute --to notebook"
nbx [--inplace] <notebook>

Bootstrap 3: Scroll bars

You need to use overflow option like below:

.nav{
    max-height: 300px;
    overflow-y: scroll; 
}

Change the height according to amount of items you need to show

Update statement with inner join on Oracle

It works fine oracle

merge into table1 t1
using (select * from table2) t2
on (t1.empid = t2.empid)
when matched then update set t1.salary = t2.salary

Oracle date difference to get number of years

If you just want the difference in years, there's:

SELECT EXTRACT(YEAR FROM date1) - EXTRACT(YEAR FROM date2) FROM mytable

Or do you want fractional years as well?

SELECT (date1 - date2) / 365.242199 FROM mytable

365.242199 is 1 year in days, according to Google.

When is del useful in Python?

I think one of the reasons that del has its own syntax is that replacing it with a function might be hard in certain cases given it operates on the binding or variable and not the value it references. Thus if a function version of del were to be created a context would need to be passed in. del foo would need to become globals().remove('foo') or locals().remove('foo') which gets messy and less readable. Still I say getting rid of del would be good given its seemingly rare use. But removing language features/flaws can be painful. Maybe python 4 will remove it :)

What is the difference between 'java', 'javaw', and 'javaws'?

java: Java application executor which is associated with a console to display output/errors

javaw: (Java windowed) application executor not associated with console. So no display of output/errors. It can be used to silently push the output/errors to text files. It is mostly used to launch GUI-based applications.

javaws: (Java web start) to download and run the distributed web applications. Again, no console is associated.

All are part of JRE and use the same JVM.

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

I have a solution below and its works for me:

app.controller('LoginController', ['$http', '$scope', function ($scope, $http) {
$scope.login = function (credentials) {
$http({
        method: 'jsonp',
        url: 'http://mywebservice',
        params: {
            format: 'jsonp',
            callback: 'JSON_CALLBACK'
        }
    }).then(function (response) {
        alert(response.data);
    });
  }
}]);

in 'http://mywebservice' there must be need a callback parameter which return JSON_CALLBACK with data.
There is a sample example below which works perfect

$scope.url = "https://angularjs.org/greet.php";
    $http({
        method: 'jsonp',
        url: $scope.url,
        params: {
            format: 'jsonp',
            name: 'Super Hero',
            callback: 'JSON_CALLBACK'
        }
    }).then(function (response) {
        alert(response.data);
    });

example output:

{"name":"Super Hero","salutation":"Apa khabar","greeting":"Apa khabar Super Hero!"}

Angular: Cannot Get /

Many answers dont really make sense but still have upvotes, makes me currious why that would still work in some cases.

In angular.json

"serve": {
  "builder": "@angular-devkit/build-angular:dev-server",
  "options": {
    "deployUrl": "/",
    "baseHref": "/",

worked for me.

reading and parsing a TSV file, then manipulating it for saving as CSV (*efficiently*)

You should use the csv module to read the tab-separated value file. Do not read it into memory in one go. Each row you read has all the information you need to write rows to the output CSV file, after all. Keep the output file open throughout.

import csv

with open('sample.txt', newline='') as tsvin, open('new.csv', 'w', newline='') as csvout:
    tsvin = csv.reader(tsvin, delimiter='\t')
    csvout = csv.writer(csvout)

    for row in tsvin:
        count = int(row[4])
        if count > 0:
            csvout.writerows([row[2:4] for _ in range(count)])

or, using the itertools module to do the repeating with itertools.repeat():

from itertools import repeat
import csv

with open('sample.txt', newline='') as tsvin, open('new.csv', 'w', newline='') as csvout:
    tsvin = csv.reader(tsvin, delimiter='\t')
    csvout = csv.writer(csvout)

    for row in tsvin:
        count = int(row[4])
        if count > 0:
            csvout.writerows(repeat(row[2:4], count))

What does "The code generator has deoptimised the styling of [some file] as it exceeds the max of "100KB"" mean?

I tried Ricardo Stuven's way but it didn't work for me. What worked in the end was adding "compact": false to my .babelrc file:

{
    "compact": false,
    "presets": ["latest", "react", "stage-0"]
}

CSS Div width percentage and padding without breaking layout

Try removing the position from header and add overflow to container:

#container {
    position:relative;
    width:80%;
    height:auto;
    overflow:auto;
}
#header {
    width:80%;
    height:50px;
    padding:10px;
}

How to check if a line is blank using regex

The most portable regex would be ^[ \t\n]*$ to match an empty string (note that you would need to replace \t and \n with tab and newline accordingly) and [^ \n\t] to match a non-whitespace string.

How to center body on a page?

Also apply text-align: center; on the html element like so:

html {
  text-align: center;
}

A better approach though is to have an inner container div, which will be centralized, and not the body.

Using Page_Load and Page_PreRender in ASP.Net

Page_Load happens after ViewState and PostData is sent into all of your server side controls by ASP.NET controls being created on the page. Page_Init is the event fired prior to ViewState and PostData being reinstated. Page_Load is where you typically do any page wide initilization. Page_PreRender is the last event you have a chance to handle prior to the page's state being rendered into HTML. Page_Load is the more typical event to work with.

static and extern global variables in C and C++

When you #include a header, it's exactly as if you put the code into the source file itself. In both cases the varGlobal variable is defined in the source so it will work no matter how it's declared.

Also as pointed out in the comments, C++ variables at file scope are not static in scope even though they will be assigned to static storage. If the variable were a class member for example, it would need to be accessible to other compilation units in the program by default and non-class members are no different.

How do I rename both a Git local and remote branch name?

  1. Rename your local branch. If you are on the branch you want to rename:

    git branch -m new-name

If you are on a different branch:

git branch -m old-name new-name
  1. Delete the old-name remote branch and push the new-name local branch.

    git push origin :old-name new-name

  2. Reset the upstream branch for the new-name local branch. Switch to the branch and then:

    git push origin -u new-name

All set!

How do I style radio buttons with images - laughing smiley for good, sad smiley for bad?

Images can be placed in place of radio buttons by using label and span elements.

   <div class="customize-radio">
        <label>Favourite Smiley</label>
        <br>
        <label for="hahaha">
          <input type="radio" name="smiley" id="hahaha">
          <span class="haha-img"></span>
          HAHAHA
        </label>
        <label for="kiss">
          <input type="radio" name="smiley" id="kiss">
          <span class="kiss-img"></span>
          Kiss
        </label>
        <label for="tongueOut">
          <input type="radio" name="smiley" id="tongueOut">
          <span class="tongueout-img"></span>
          TongueOut
        </label>
    </div>

Radio button should be hidden,

.customize-radio label > input[type = 'radio'] {
    visibility: hidden;
    position: absolute;
}

Image can be given in the span tag,

.customize-radio label > input[type = 'radio'] ~ span{
    cursor: pointer;
    width: 27px;
    height: 24px;
    display: inline-block;
    background-size: 27px 24px;
    background-repeat: no-repeat;
}
.haha-img {
    background-image: url('hahabefore.png');
}

.kiss-img{
    background-image: url('kissbefore.png');
}
.tongueout-img{
    background-image: url('tongueoutbefore.png');
}

To change the image on click of radio button, add checked state to the input tag,

.customize-radio label > input[type = 'radio']:checked ~ span.haha-img{
     background-image: url('haha.png');
}
.customize-radio label > input[type = 'radio']:checked ~ span.kiss-img{
    background-image: url('kiss.png');
}
.customize-radio label > input[type = 'radio']:checked ~ span.tongueout-img{
        background-image: url('tongueout.png');
}

If you have any queries, Refer to the following link, As I have taken solution from the below blog, http://frontendsupport.blogspot.com/2018/06/cool-radio-buttons-with-images.html

How to: Install Plugin in Android Studio

  1. Launch Android Studio application
  2. Choose Project Settings
  3. Choose Plugin from disk, if on disk then choose that location of *.jar, in my case is GenyMotion jar
  4. Click on Apply and OK.
  5. Then Android studio will ask for Restart.

That's all Folks! enter image description here

How to get the position of a character in Python?

What happens when the string contains a duplicate character? from my experience with index() I saw that for duplicate you get back the same index.

For example:

s = 'abccde'
for c in s:
    print('%s, %d' % (c, s.index(c)))

would return:

a, 0
b, 1
c, 2
c, 2
d, 4

In that case you can do something like that:

for i, character in enumerate(my_string):
   # i is the position of the character in the string

Populate unique values into a VBA array from Excel

If you don't mind using the Variant data type, then you can use the in-built worksheet function Unique as shown.

sub unique_results_to_array()
    dim rng_data as Range
    set rng_data = activesheet.range("A1:A10") 'enter the range of data here

    dim my_arr() as Variant
    my_arr = WorksheetFunction.Unique(rng_data)
    
    first_val  = my_arr(1,1)
    second_val = my_arr(2,1)
    third_val = my_arr(3,1)   'etc...    

end sub

Create directories using make file

See https://www.oreilly.com/library/view/managing-projects-with/0596006101/ch12.html

REQUIRED_DIRS = ...
_MKDIRS := $(shell for d in $(REQUIRED_DIRS); \
             do                               \
               [[ -d $$d ]] || mkdir -p $$d;  \
             done)

$(objects) : $(sources)

As I use Ubuntu, I also needed add this at the top of my Makefile:

SHELL := /bin/bash # Use bash syntax

Getting Image from API in Angular 4/5+?

angular 5 :

 getImage(id: string): Observable<Blob> {
    return this.httpClient.get('http://myip/image/'+id, {responseType: "blob"});
}

Set cookies for cross origin requests

For express, upgrade your express library to 4.17.1 which is the latest stable version. Then;

In CorsOption: Set origin to your localhost url or your frontend production url and credentials to true e.g

  const corsOptions = {
    origin: config.get("origin"),
    credentials: true,
  };

I set my origin dynamically using config npm module.

Then , in res.cookie:

For localhost: you do not need to set sameSite and secure option at all, you can set httpOnly to true for http cookie to prevent XSS attack and other useful options depending on your use case.

For production environment, you need to set sameSite to none for cross-origin request and secure to true. Remember sameSite works with express latest version only as at now and latest chrome version only set cookie over https, thus the need for secure option.

Here is how I made mine dynamic

 res
    .cookie("access_token", token, {
      httpOnly: true,
      sameSite: app.get("env") === "development" ? true : "none",
      secure: app.get("env") === "development" ? false : true,
    })

UTF-8 text is garbled when form is posted as multipart/form-data

The filter thing and setting up Tomcat to support UTF-8 URIs is only important if you're passing the via the URL's query string, as you would with a HTTP GET. If you're using a POST, with a query string in the HTTP message's body, what's important is going to be the content-type of the request and this will be up to the browser to set the content-type to UTF-8 and send the content with that encoding.

The only way to really do this is by telling the browser that you can only accept UTF-8 by setting the Accept-Charset header on every response to "UTF-8;q=1,ISO-8859-1;q=0.6". This will put UTF-8 as the best quality and the default charset, ISO-8859-1, as acceptable, but a lower quality.

When you say the file name is garbled, is it garbled in the HttpServletRequest.getParameter's return value?

Removing white space around a saved image in matplotlib

This worked for me plt.savefig(save_path,bbox_inches='tight', pad_inches=0, transparent=True)

Mismatch Detected for 'RuntimeLibrary'

I had this problem along with mismatch in ITERATOR_DEBUG_LEVEL. As a sunday-evening problem after all seemed ok and good to go, I was put out for some time. Working in de VS2017 IDE (Solution Explorer) I had recently added/copied a sourcefile reference to my project (ctrl-drag) from another project. Looking into properties->C/C++/Preprocessor - at source file level, not project level - I noticed that in a Release configuration _DEBUG was specified instead of NDEBUG for this source file. Which was all the change needed to get rid of the problem.

How can I convert an MDB (Access) file to MySQL (or plain SQL file)?

OSX users can follow by Nicolay77 or mikkom that uses the mdbtools utility. You can install it via Homebrew. Just have your homebrew installed and then go

$ homebrew install mdbtools

Then create one of the scripts described by the guys and use it. I've used mikkom's one, converted all my mdb files into sql.

$ ./to_mysql.sh myfile.mdb > myfile.sql

(which btw contains more than 1 table)

How to escape special characters in building a JSON string?

The answer the direct question:
To be safe, replace the required character with \u+4-digit-hex-value

Example: If you want to escape the apostrophe ' replace with \u0027
D'Amico becomes D\u0027Amico

NICE REFERENCE: http://es5.github.io/x7.html#x7.8.4

https://mathiasbynens.be/notes/javascript-escapes

Override body style for content in an iframe

Perhaps it's changed now, but I have used a separate stylesheet with this element:

.feedEkList iframe
{
max-width: 435px!important;
width: 435px!important;
height: 320px!important;
}

to successfully style embedded youtube iframes...see the blog posts on this page.

How to use Global Variables in C#?

A useful feature for this is using static

As others have said, you have to create a class for your globals:

public static class Globals {
    public const float PI = 3.14;
}

But you can import it like this in order to no longer write the class name in front of its static properties:

using static Globals;
[...]
Console.WriteLine("Pi is " + PI);

disable viewport zooming iOS 10+ safari?

It's possible to prevent webpage scaling in safari on iOS 10, but it's going to involve more work on your part. I guess the argument is that a degree of difficulty should stop cargo-cult devs from dropping "user-scalable=no" into every viewport tag and making things needlessly difficult for vision-impaired users.

Still, I would like to see Apple change their implementation so that there is a simple (meta-tag) way to disable double-tap-to-zoom. Most of the difficulties relate to that interaction.

You can stop pinch-to-zoom with something like this:

document.addEventListener('touchmove', function (event) {
  if (event.scale !== 1) { event.preventDefault(); }
}, false);

Note that if any deeper targets call stopPropagation on the event, the event will not reach the document and the scaling behavior will not be prevented by this listener.

Disabling double-tap-to-zoom is similar. You disable any tap on the document occurring within 300 milliseconds of the prior tap:

var lastTouchEnd = 0;
document.addEventListener('touchend', function (event) {
  var now = (new Date()).getTime();
  if (now - lastTouchEnd <= 300) {
    event.preventDefault();
  }
  lastTouchEnd = now;
}, false);

If you don't set up your form elements right, focusing on an input will auto-zoom, and since you have mostly disabled manual zoom, it will now be almost impossible to unzoom. Make sure the input font size is >= 16px.

If you're trying to solve this in a WKWebView in a native app, the solution given above is viable, but this is a better solution: https://stackoverflow.com/a/31943976/661418. And as mentioned in other answers, in iOS 10 beta 6, Apple has now provided a flag to honor the meta tag.

Update May 2017: I replaced the old 'check touches length on touchstart' method of disabling pinch-zoom with a simpler 'check event.scale on touchmove' approach. Should be more reliable for everyone.

The Eclipse executable launcher was unable to locate its companion launcher jar windows

In my case I had to redownload it, something was wrong with the one I downloaded. Its size was far much less than the one on the website.

How to check if array element exists or not in javascript?

This also works fine, testing by type against undefined.

if (currentData[index] === undefined){return}

Test:

_x000D_
_x000D_
const fruits = ["Banana", "Orange", "Apple", "Mango"];_x000D_
_x000D_
if (fruits["Raspberry"] === undefined){_x000D_
  console.log("No Raspberry entry in fruits!")_x000D_
}
_x000D_
_x000D_
_x000D_

cmd line rename file with date and time

Animuson gives a decent way to do it, but no help on understanding it. I kept looking and came across a forum thread with this commands:

Echo Off
IF Not EXIST n:\dbfs\doekasp.txt GOTO DoNothing

copy n:\dbfs\doekasp.txt n:\history\doekasp.txt

Rem rename command is done twice (2) to allow for 1 or 2 digit hour,
Rem If before 10am (1digit) hour Rename starting at location (0) for (2) chars,
Rem will error out, as location (0) will have a space
Rem and space is invalid character for file name,
Rem so second remame will be used.
Rem
Rem if equal 10am or later (2 digit hour) then first remame will work and second will not
Rem as doekasp.txt will not be found (remamed)


ren n:\history\doekasp.txt doekasp-%date:~4,2%-%date:~7,2%-%date:~10,4%_@_%time:~0,2%h%time:~3,2%m%time:~6,2%s%.txt
ren n:\history\doekasp.txt doekasp-%date:~4,2%-%date:~7,2%-%date:~10,4%_@_%time:~1,1%h%time:~3,2%m%time:~6,2%s%.txt

I always name year first YYYYMMDD, but wanted to add time. Here you will see that he has given a reason why 0,2 will not work and 1,1 will, because (space) is an invalid character. This opened my eyes to the issue. Also, by default you're in 24hr mode.

I ended up with:

ren Logs.txt Logs-%date:~10,4%%date:~7,2%%date:~4,2%_%time:~0,2%%time:~3,2%.txt
ren Logs.txt Logs-%date:~10,4%%date:~7,2%%date:~4,2%_%time:~1,1%%time:~3,2%.txt

Output:

Logs-20121707_1019

Pointers, smart pointers or shared pointers?

Sydius outlined the types fairly well:

  • Normal pointers are just that - they point to some thing in memory somewhere. Who owns it? Only the comments will let you know. Who frees it? Hopefully the owner at some point.
  • Smart pointers are a blanket term that cover many types; I'll assume you meant scoped pointer which uses the RAII pattern. It is a stack-allocated object that wraps a pointer; when it goes out of scope, it calls delete on the pointer it wraps. It "owns" the contained pointer in that it is in charge of deleteing it at some point. They allow you to get a raw reference to the pointer they wrap for passing to other methods, as well as releasing the pointer, allowing someone else to own it. Copying them does not make sense.
  • Shared pointers is a stack-allocated object that wraps a pointer so that you don't have to know who owns it. When the last shared pointer for an object in memory is destructed, the wrapped pointer will also be deleted.

How about when you should use them? You will either make heavy use of scoped pointers or shared pointers. How many threads are running in your application? If the answer is "potentially a lot", shared pointers can turn out to be a performance bottleneck if used everywhere. The reason being that creating/copying/destructing a shared pointer needs to be an atomic operation, and this can hinder performance if you have many threads running. However, it won't always be the case - only testing will tell you for sure.

There is an argument (that I like) against shared pointers - by using them, you are allowing programmers to ignore who owns a pointer. This can lead to tricky situations with circular references (Java will detect these, but shared pointers cannot) or general programmer laziness in a large code base.

There are two reasons to use scoped pointers. The first is for simple exception safety and cleanup operations - if you want to guarantee that an object is cleaned up no matter what in the face of exceptions, and you don't want to stack allocate that object, put it in a scoped pointer. If the operation is a success, you can feel free to transfer it over to a shared pointer, but in the meantime save the overhead with a scoped pointer.

The other case is when you want clear object ownership. Some teams prefer this, some do not. For instance, a data structure may return pointers to internal objects. Under a scoped pointer, it would return a raw pointer or reference that should be treated as a weak reference - it is an error to access that pointer after the data structure that owns it is destructed, and it is an error to delete it. Under a shared pointer, the owning object can't destruct the internal data it returned if someone still holds a handle on it - this could leave resources open for much longer than necessary, or much worse depending on the code.

Can't bind to 'ngForOf' since it isn't a known property of 'tr' (final release)

This can also happen if you don't declare a route component in your feature module. So for example:

feature.routing.module.ts:

...
    {
        path: '',
        component: ViewComponent,
    }
...

feature.module.ts:

     imports: [ FeatureRoutingModule ],
     declarations: [],

Notice the ViewComponent is not in the declarations array, whereas it should be.

Generate C# class from XML

To convert XML into a C# Class:

  • Navigate to the Microsoft Visual Studio Marketplace: -- https://marketplace.visualstudio.com
  • In the search bar enter text: -- xml to class code tool
  • Download, install, and use the app

Note: in the fullness of time, this app may be replaced, but chances are, there'll be another tool that does the same thing.

Convert month int to month name

CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName(1);

See Here for more details.

Or

DateTime dt = DateTime.Now;
Console.WriteLine( dt.ToString( "MMMM" ) );

Or if you want to get the culture-specific abbreviated name.

GetAbbreviatedMonthName(1);

Reference

<div> cannot appear as a descendant of <p>

I got this warning by using Material UI components, then I test the component="div" as prop to the below code and everything became correct:

import Grid from '@material-ui/core/Grid';
import Typography from '@material-ui/core/Typography';

<Typography component="span">
  <Grid component="span">
    Lorem Ipsum
  </Grid>
</Typography>

Actually, this warning happens because in the Material UI the default HTML tag of Grid component is div tag and the default Typography HTML tag is p tag, So now the warning happens,

Warning: validateDOMnesting(...): <div> cannot appear as a descendant of <p>

How to get duplicate items from a list using LINQ?

Here is one way to do it:

List<String> duplicates = lst.GroupBy(x => x)
                             .Where(g => g.Count() > 1)
                             .Select(g => g.Key)
                             .ToList();

The GroupBy groups the elements that are the same together, and the Where filters out those that only appear once, leaving you with only the duplicates.

Change variable name in for loop using R

Another option is using eval and parse, as in

d = 5
for (i in 1:10){
     eval(parse(text = paste('a', 1:10, ' = d + rnorm(3)', sep='')[i]))
}

jquery datatables default sort

You can use the fnSort function, see the details here:

http://datatables.net/api#fnSort

How to enable/disable bluetooth programmatically in android

Here is a bit more robust way of doing this, also handling the return values of enable()\disable() methods:

public static boolean setBluetooth(boolean enable) {
    BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    boolean isEnabled = bluetoothAdapter.isEnabled();
    if (enable && !isEnabled) {
        return bluetoothAdapter.enable(); 
    }
    else if(!enable && isEnabled) {
        return bluetoothAdapter.disable();
    }
    // No need to change bluetooth state
    return true;
}

And add the following permissions into your manifest file:

<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>

But remember these important points:

This is an asynchronous call: it will return immediately, and clients should listen for ACTION_STATE_CHANGED to be notified of subsequent adapter state changes. If this call returns true, then the adapter state will immediately transition from STATE_OFF to STATE_TURNING_ON, and some time later transition to either STATE_OFF or STATE_ON. If this call returns false then there was an immediate problem that will prevent the adapter from being turned on - such as Airplane mode, or the adapter is already turned on.

UPDATE:

Ok, so how to implement bluetooth listener?:

private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        final String action = intent.getAction();

        if (action.equals(BluetoothAdapter.ACTION_STATE_CHANGED)) {
            final int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE,
                                                 BluetoothAdapter.ERROR);
            switch (state) {
            case BluetoothAdapter.STATE_OFF:
                // Bluetooth has been turned off;
                break;
            case BluetoothAdapter.STATE_TURNING_OFF:
                // Bluetooth is turning off;
                break;
            case BluetoothAdapter.STATE_ON:
                // Bluetooth is on
                break;
            case BluetoothAdapter.STATE_TURNING_ON:
                // Bluetooth is turning on
                break;
            }
        }
    }
};

And how to register/unregister the receiver? (In your Activity class)

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // ...

    // Register for broadcasts on BluetoothAdapter state change
    IntentFilter filter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
    registerReceiver(mReceiver, filter);
}

@Override
public void onStop() {
    super.onStop();

     // ...

    // Unregister broadcast listeners
    unregisterReceiver(mReceiver);
}

How to clean node_modules folder of packages that are not in package.json?

simple just run

rm -r node_modules

in fact, you can delete any folder with this.

like rm -r AnyFolderWhichIsNotDeletableFromShiftDeleteOrDelete.

just open the gitbash move to root of the folder and run this command

Hope this will help.

Getting and removing the first character of a string

removing first characters:

x <- 'hello stackoverflow'
substring(x, 2, nchar(x))

Idea is select all characters starting from 2 to number of characters in x. This is important when you have unequal number of characters in word or phrase.

Selecting the first letter is trivial as previous answers:

substring(x,1,1)

How to prevent null values inside a Map and null fields inside a bean from getting serialized through Jackson

Answer seems to be a little old, What I did was to use this mapper to convert a MAP

      ObjectMapper mapper = new ObjectMapper().configure(SerializationConfig.Feature.WRITE_NULL_MAP_VALUES, false);

a simple Map:

          Map<String, Object> user = new HashMap<String,Object>();
            user.put( "id",  teklif.getAccount().getId() );
            user.put( "fname", teklif.getAccount().getFname());
            user.put( "lname", teklif.getAccount().getLname());
            user.put( "email", teklif.getAccount().getEmail());
            user.put( "test", null);

Use it like this for example:

      String json = mapper.writeValueAsString(user);

Open soft keyboard programmatically

Post this method in your base activity and use it other activities like a charm

public void openKeyboard() {
    InputMethodManager imm =
            (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    if (imm != null) {
        imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0);
    }
}

Why would anybody use C over C++?

Most of the significant features of c++ somehow involve classes or templates. These are wonderful features except for the way the compiler transforms these into object code. Most compilers use name mangling, and the ones that don't do something at least as messy.

If your system lives on its own, as is the case with many applications, then C++ is a fine choice.

If your system needs to interact with software not neccesarily written in C++ (most frequently in assembler, or Fortran Libraries) then you are in a tight spot. To interact with those kinds of cases, you'll need to disable name mangling for those symbols. this is usually done by declaring those objects extern "C", but then they can't be templates, overloaded functions, or classes. If those are likely to be your applications API, then you'll have to wrap them with helper functions, and keep those functions in sync with the actual implementations.

And in reality, the C++ language provides a standard syntax for features that can be easily implemented in pure C.

In short, the overhead of interoperable C++ is too high for most folks to justify.

Convert list or numpy array of single element to float in python

You may want to use the ndarray.item method, as in a.item(). This is also equivalent to (the now deprecated) np.asscalar(a). This has the benefit of working in situations with views and superfluous axes, while the above solutions will currently break. For example,

>>> a = np.asarray(1).view()
>>> a.item()  # correct
1

>>> a[0]  # breaks
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
IndexError: too many indices for array


>>> a = np.asarray([[2]])
>>> a.item()  # correct
2

>>> a[0]  # bad result
array([2])

This also has the benefit of throwing an exception if the array is not a singleton, while the a[0] approach will silently proceed (which may lead to bugs sneaking through undetected).

>>> a = np.asarray([1, 2])
>>> a[0]  # silently proceeds
1
>>> a.item()  # detects incorrect size
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: can only convert an array of size 1 to a Python scalar

Auto select file in Solution Explorer from its open tab

It's in VS2012 - Specifically the 2-Arrow icon at the top of the solution explorer (Left/Right arrows, one above the other). This automatically jumps to the current file.

This icon is only visible if you've got Track Active Item in Solution Explorer disabled.

Checking if a SQL Server login already exists

This works on SQL Server 2000.

use master
select count(*) From sysxlogins WHERE NAME = 'myUsername'

on SQL 2005, change the 2nd line to

select count(*) From syslogins WHERE NAME = 'myUsername'

I'm not sure about SQL 2008, but I'm guessing that it will be the same as SQL 2005 and if not, this should give you an idea of where t start looking.

What is an idiomatic way of representing enums in Go?

I am sure we have a lot of good answers here. But, I just thought of adding the way I have used enumerated types

package main

import "fmt"

type Enum interface {
    name() string
    ordinal() int
    values() *[]string
}

type GenderType uint

const (
    MALE = iota
    FEMALE
)

var genderTypeStrings = []string{
    "MALE",
    "FEMALE",
}

func (gt GenderType) name() string {
    return genderTypeStrings[gt]
}

func (gt GenderType) ordinal() int {
    return int(gt)
}

func (gt GenderType) values() *[]string {
    return &genderTypeStrings
}

func main() {
    var ds GenderType = MALE
    fmt.Printf("The Gender is %s\n", ds.name())
}

This is by far one of the idiomatic ways we could create Enumerated types and use in Go.

Edit:

Adding another way of using constants to enumerate

package main

import (
    "fmt"
)

const (
    // UNSPECIFIED logs nothing
    UNSPECIFIED Level = iota // 0 :
    // TRACE logs everything
    TRACE // 1
    // INFO logs Info, Warnings and Errors
    INFO // 2
    // WARNING logs Warning and Errors
    WARNING // 3
    // ERROR just logs Errors
    ERROR // 4
)

// Level holds the log level.
type Level int

func SetLogLevel(level Level) {
    switch level {
    case TRACE:
        fmt.Println("trace")
        return

    case INFO:
        fmt.Println("info")
        return

    case WARNING:
        fmt.Println("warning")
        return
    case ERROR:
        fmt.Println("error")
        return

    default:
        fmt.Println("default")
        return

    }
}

func main() {

    SetLogLevel(INFO)

}

Hidden Columns in jqGrid

It is a bit old, this post. But this is my code to show/hide the columns. I use the built in function to display the columns and just mark them.

Function that displays columns shown/hidden columns. The #jqGrid is the name of my grid, and the columnChooser is the jqGrid column chooser.

  function showHideColumns() {
        $('#jqGrid').jqGrid('columnChooser', {
            width: 250,
            dialog_opts: {
                modal: true,
                minWidth: 250,
                height: 300,
                show: 'blind',
                hide: 'explode',
                dividerLocation: 0.5
            } });

How to change font size in Eclipse for Java text editors?

On the Eclipse toolbar, select Window ? Preferences, set the font size (General ? Appearance ? Colors and Fonts ? Basic ? Text Font).

Save the preferences.

How to make a HTTP PUT request?

My Final Approach:

    public void PutObject(string postUrl, object payload)
        {
            var request = (HttpWebRequest)WebRequest.Create(postUrl);
            request.Method = "PUT";
            request.ContentType = "application/xml";
            if (payload !=null)
            {
                request.ContentLength = Size(payload);
                Stream dataStream = request.GetRequestStream();
                Serialize(dataStream,payload);
                dataStream.Close();
            }

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            string returnString = response.StatusCode.ToString();
        }

public void Serialize(Stream output, object input)
            {
                var ser = new DataContractSerializer(input.GetType());
                ser.WriteObject(output, input);
            }

How to get String Array from arrays.xml file

Your XML is not entirely clear, but arrays XML can cause force closes if you make them numbers, and/or put white space in their definition.

Make sure they are defined like No Leading or Trailing Whitespace

android.view.InflateException: Binary XML file: Error inflating class fragment

I had this error too, and after very long debugging the problem seamed to be that my MainClass extended Activity instead of FrameActivity, in my case, the xml wasn't a problem. Hope to help you.

How to represent multiple conditions in a shell if statement?

#!/bin/bash

current_usage=$( df -h | grep 'gfsvg-gfslv' | awk {'print $5'} )
echo $current_usage
critical_usage=6%
warning_usage=3%

if [[ ${current_usage%?} -lt ${warning_usage%?} ]]; then
echo OK current usage is $current_usage
elif [[ ${current_usage%?} -ge ${warning_usage%?} ]] && [[ ${current_usage%?} -lt ${critical_usage%?} ]]; then
echo Warning $current_usage
else
echo Critical $current_usage
fi

Good tool to visualise database schema?

ER/Studio by Embarcadero is one of the costlier ones, but the hierarchical mode it present is by far the best one for understanding database models. It makes query writing the easiest task in the world.

It also is incredible with normalization, denormalization, warehousing, documentation, etc.

The downside is that it is a pretty expensive tool especially when you go multiplatform.

How to draw text using only OpenGL methods?

enter image description here

Use glutStrokeCharacter(GLUT_STROKE_ROMAN, myCharString).

An example: A STAR WARS SCROLLER.

#include <windows.h>
#include <string.h>
#include <GL\glut.h>
#include <iostream.h>
#include <fstream.h>

GLfloat UpwardsScrollVelocity = -10.0;
float view=20.0;

char quote[6][80];
int numberOfQuotes=0,i;

//*********************************************
//*  glutIdleFunc(timeTick);                  *
//*********************************************

void timeTick(void)
{
    if (UpwardsScrollVelocity< -600)
        view-=0.000011;
    if(view < 0) {view=20; UpwardsScrollVelocity = -10.0;}
    //  exit(0);
    UpwardsScrollVelocity -= 0.015;
  glutPostRedisplay();

}


//*********************************************
//* printToConsoleWindow()                *
//*********************************************

void printToConsoleWindow()
{
    int l,lenghOfQuote, i;

    for(  l=0;l<numberOfQuotes;l++)
    {
        lenghOfQuote = (int)strlen(quote[l]);

        for (i = 0; i < lenghOfQuote; i++)
        {
          //cout<<quote[l][i];
        }
          //out<<endl;
    }

}

//*********************************************
//* RenderToDisplay()                       *
//*********************************************

void RenderToDisplay()
{
    int l,lenghOfQuote, i;

    glTranslatef(0.0, -100, UpwardsScrollVelocity);
    glRotatef(-20, 1.0, 0.0, 0.0);
    glScalef(0.1, 0.1, 0.1);



    for(  l=0;l<numberOfQuotes;l++)
    {
        lenghOfQuote = (int)strlen(quote[l]);
        glPushMatrix();
        glTranslatef(-(lenghOfQuote*37), -(l*200), 0.0);
        for (i = 0; i < lenghOfQuote; i++)
        {
            glColor3f((UpwardsScrollVelocity/10)+300+(l*10),(UpwardsScrollVelocity/10)+300+(l*10),0.0);
            glutStrokeCharacter(GLUT_STROKE_ROMAN, quote[l][i]);
        }
        glPopMatrix();
    }

}
//*********************************************
//* glutDisplayFunc(myDisplayFunction);       *
//*********************************************

void myDisplayFunction(void)
{
  glClear(GL_COLOR_BUFFER_BIT);
  glLoadIdentity();
  gluLookAt(0.0, 30.0, 100.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
  RenderToDisplay();
  glutSwapBuffers();
}
//*********************************************
//* glutReshapeFunc(reshape);               *
//*********************************************

void reshape(int w, int h)
{
  glViewport(0, 0, w, h);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(60, 1.0, 1.0, 3200);
  glMatrixMode(GL_MODELVIEW);
}

//*********************************************
//* int main()                                *
//*********************************************


int main()
{
    strcpy(quote[0],"Luke, I am your father!.");
    strcpy(quote[1],"Obi-Wan has taught you well. ");
    strcpy(quote[2],"The force is strong with this one. ");
    strcpy(quote[3],"Alert all commands. Calculate every possible destination along their last known trajectory. ");
    strcpy(quote[4],"The force is with you, young Skywalker, but you are not a Jedi yet.");
    numberOfQuotes=5;

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(800, 400);
    glutCreateWindow("StarWars scroller");
    glClearColor(0.0, 0.0, 0.0, 1.0);
    glLineWidth(3);

    glutDisplayFunc(myDisplayFunction);
    glutReshapeFunc(reshape);
    glutIdleFunc(timeTick);
    glutMainLoop();

    return 0;
}

Splitting a Java String by the pipe symbol using split("|")

Use this code:

public static void main(String[] args) {
    String test = "A|B|C||D";

    String[] result = test.split("\\|");

    for (String s : result) {
        System.out.println(">" + s + "<");
    }
}

How to increment variable under DOS?

Indeed, set in DOS has no option to allow for arithmetic. You could do a giant lookup table, though:

if %COUNTER%==249 set COUNTER=250
...
if %COUNTER%==3 set COUNTER=4
if %COUNTER%==2 set COUNTER=3
if %COUNTER%==1 set COUNTER=2
if %COUNTER%==0 set COUNTER=1

PHP how to get the base domain/url?

2 lines to solve it

$actual_link = (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on' ? "https" : "http") . "://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
$myDomain = preg_replace('/^www\./', '', parse_url($actual_link, PHP_URL_HOST));

How to make a <ul> display in a horizontal row

As @alex said, you could float it right, but if you wanted to keep the markup the same, float it to the left!

#ul_top_hypers li {
    float: left;
}

Format number to always show 2 decimal places

A much more generic solution for rounding to N places

function roundN(num,n){
  return parseFloat(Math.round(num * Math.pow(10, n)) /Math.pow(10,n)).toFixed(n);
}


console.log(roundN(1,2))
console.log(roundN(1.34,2))
console.log(roundN(1.35,2))
console.log(roundN(1.344,2))
console.log(roundN(1.345,2))
console.log(roundN(1.344,3))
console.log(roundN(1.345,3))
console.log(roundN(1.3444,3))
console.log(roundN(1.3455,3))

Output

1.00
1.34
1.35
1.34
1.35
1.344
1.345
1.344
1.346

Drop multiple columns in pandas

Try this

df.drop(df.iloc[:, 1:69], inplace=True, axis=1)

This works for me

How to access Anaconda command prompt in Windows 10 (64-bit)

How to add anaconda installation directory to your PATH variables

1. open environmental variables window

Do this by either going to my computer and then right clicking the background for the context menu > "properties". On the left side open "advanced system settings" or just search for "env..." in start menu ([Win]+[s] keys).

Then click on environment variables

If you struggle with this step read this explanation.

2. Edit Path in the user environmental variables section and add three new entries:

  • D:\path\to\anaconda3
  • D:\path\to\anaconda3\Scripts
  • D:\path\to\anaconda3\Library\bin

D:\path\to\anaconda3 should be the folder where you have installed anaconda

Click [OK] on all opened windows.

If you did everything correctly, you can test a conda command by opening a new powershell window.

conda --version

This should output something like: conda 4.8.2

How to show "if" condition on a sequence diagram?

If else condition, also called alternatives in UML terms can indeed be represented in sequence diagrams. Here is a link where you can find some nice resources on the subject http://www.ibm.com/developerworks/rational/library/3101.html

branching with alt

Why does npm install say I have unmet dependencies?

Take care about your angular version, if you work under angular 2.x.x so maybe you need to upgrade to angular 4.x.x

Some dependencies needs angular 4

Here is a tutorial for how to install angular 4 or update your project.

Combine two tables that have no common fields

Joining Non-Related Tables

enter image description here

Demo SQL Script

IF OBJECT_ID('Tempdb..#T1') IS NOT NULL  DROP TABLE #T1;

CREATE TABLE #T1 (T1_Name VARCHAR(75));

INSERT INTO #T1 (T1_Name) VALUES ('Animal'),('Bat'),('Cat'),('Duet');

SELECT * FROM #T1;

IF OBJECT_ID('Tempdb..#T2') IS NOT NULL  DROP TABLE #T2;

CREATE TABLE #T2 (T2_Class VARCHAR(10));

INSERT INTO #T2 (T2_Class) VALUES ('Z'),('T'),('H'); 

SELECT * FROM #T2;

To Join Non-Related Tables , we are going to introduce one common joining column of Serial Numbers like below.

SQL Script

SELECT T1.T1_Name,ISNULL(T2.T2_Class,'') AS T2_Class FROM
( SELECT T1_Name,ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) AS S_NO FROM #T1) T1
LEFT JOIN
( SELECT T2_Class,ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) AS S_NO FROM #T2) T2
ON t1.S_NO=T2.S_NO;

How to determine an interface{} value's "real" type?

I'm going to offer up a way to return a boolean based on passing an argument of a reflection Kinds to a local type receiver (because I couldn't find anything like this).

First, we declare our anonymous type of type reflect.Value:

type AnonymousType reflect.Value

Then we add a builder for our local type AnonymousType which can take in any potential type (as an interface):

func ToAnonymousType(obj interface{}) AnonymousType {
    return AnonymousType(reflect.ValueOf(obj))
}

Then we add a function for our AnonymousType struct which asserts against a reflect.Kind:

func (a AnonymousType) IsA(typeToAssert reflect.Kind) bool {
    return typeToAssert == reflect.Value(a).Kind()
}

This allows us to call the following:

var f float64 = 3.4

anon := ToAnonymousType(f)

if anon.IsA(reflect.String) {
    fmt.Println("Its A String!")
} else if anon.IsA(reflect.Float32) {
    fmt.Println("Its A Float32!")
} else if anon.IsA(reflect.Float64) {
    fmt.Println("Its A Float64!")
} else {
    fmt.Println("Failed")
}

Can see a longer, working version here:https://play.golang.org/p/EIAp0z62B7

How to remove all elements in String array in java?

Just Re-Initialize the array

example = new String[size]

or If it is inside a running loop,Just Re-declare it again,

**for(int i=1;i<=100;i++) { String example = new String[size] //Your code goes here`` }**

phpMyAdmin access denied for user 'root'@'localhost' (using password: NO)

Edit the file xampp/mysql/bin/my.ini

Add

skip-grant-tables

under [mysqld]

How to convert a 3D point into 2D perspective projection?

I think this will probably answer your question. Here's what I wrote there:

Here's a very general answer. Say the camera's at (Xc, Yc, Zc) and the point you want to project is P = (X, Y, Z). The distance from the camera to the 2D plane onto which you are projecting is F (so the equation of the plane is Z-Zc=F). The 2D coordinates of P projected onto the plane are (X', Y').

Then, very simply:

X' = ((X - Xc) * (F/Z)) + Xc

Y' = ((Y - Yc) * (F/Z)) + Yc

If your camera is the origin, then this simplifies to:

X' = X * (F/Z)

Y' = Y * (F/Z)

Rails: Get Client IP address

Get client ip using command:

request.remote_ip

What exactly do "u" and "r" string flags do, and what are raw string literals?

Let me explain it simply: In python 2, you can store string in 2 different types.

The first one is ASCII which is str type in python, it uses 1 byte of memory. (256 characters, will store mostly English alphabets and simple symbols)

The 2nd type is UNICODE which is unicode type in python. Unicode stores all types of languages.

By default, python will prefer str type but if you want to store string in unicode type you can put u in front of the text like u'text' or you can do this by calling unicode('text')

So u is just a short way to call a function to cast str to unicode. That's it!

Now the r part, you put it in front of the text to tell the computer that the text is raw text, backslash should not be an escaping character. r'\n' will not create a new line character. It's just plain text containing 2 characters.

If you want to convert str to unicode and also put raw text in there, use ur because ru will raise an error.

NOW, the important part:

You cannot store one backslash by using r, it's the only exception. So this code will produce error: r'\'

To store a backslash (only one) you need to use '\\'

If you want to store more than 1 characters you can still use r like r'\\' will produce 2 backslashes as you expected.

I don't know the reason why r doesn't work with one backslash storage but the reason isn't described by anyone yet. I hope that it is a bug.

Use grep --exclude/--include syntax to not grep through certain files

grep 2.5.3 introduced the --exclude-dir parameter which will work the way you want.

grep -rI --exclude-dir=\.svn PATTERN .

You can also set an environment variable: GREP_OPTIONS="--exclude-dir=\.svn"

I'll second Andy's vote for ack though, it's the best.

How to print matched regex pattern using awk?

It sounds like you are trying to emulate GNU's grep -o behaviour. This will do that providing you only want the first match on each line:

awk 'match($0, /regex/) {
    print substr($0, RSTART, RLENGTH)
}
' file

Here's an example, using GNU's awk implementation ():

awk 'match($0, /a.t/) {
    print substr($0, RSTART, RLENGTH)
}
' /usr/share/dict/words | head
act
act
act
act
aft
ant
apt
art
art
art

Read about match, substr, RSTART and RLENGTH in the awk manual.

After that you may wish to extend this to deal with multiple matches on the same line.

Tool for sending multipart/form-data request

UPDATE: I have created a video on sending multipart/form-data requests to explain this better.


Actually, Postman can do this. Here is a screenshot

Newer version : Screenshot captured from postman chrome extension enter image description here

Another version

enter image description here

Older version

enter image description here

Make sure you check the comment from @maxkoryukov

Be careful with explicit Content-Type header. Better - do not set it's value, the Postman is smart enough to fill this header for you. BUT, if you want to set the Content-Type: multipart/form-data - do not forget about boundary field.

Why can't I find SQL Server Management Studio after installation?

It appears that SQL Server 2008 R2 can be downloaded with or without the management tools. I honestly have NO IDEA why someone would not want the management tools. But either way, the options are here:

http://www.microsoft.com/sqlserver/en/us/editions/express.aspx

and the one for 64 bit WITH the management tools (management studio) is here:

http://www.microsoft.com/sqlserver/en/us/editions/express.aspx

From the first link I presented, the 3rd and 4th include the management studio for 32 and 64 bit respectively.

Update or Insert (multiple rows and columns) from subquery in PostgreSQL

UPDATE table1 SET (col1, col2) = (col2, col3) FROM othertable WHERE othertable.col1 = 123;

Get immediate first child element

Both these will give you the first child node:

console.log(parentElement.firstChild); // or
console.log(parentElement.childNodes[0]);

If you need the first child that is an element node then use:

console.log(parentElement.children[0]);

Edit

Ah, I see your problem now; parentElement is an array.

If you know that getElementsByClassName will only return one result, which it seems you do, you should use [0] to dearray (yes, I made that word up) the element:

var parentElement = document.getElementsByClassName("uniqueClassName")[0];

How to convert std::chrono::time_point to calendar datetime string with fractional seconds?

This worked for me for a format like YYYY.MM.DD-HH.MM.SS.fff. Attempting to make this code capable of accepting any string format will be like reinventing the wheel (i.e. there are functions for all this in Boost.

std::chrono::system_clock::time_point string_to_time_point(const std::string &str)
{
    using namespace std;
    using namespace std::chrono;

    int yyyy, mm, dd, HH, MM, SS, fff;

    char scanf_format[] = "%4d.%2d.%2d-%2d.%2d.%2d.%3d";

    sscanf(str.c_str(), scanf_format, &yyyy, &mm, &dd, &HH, &MM, &SS, &fff);

    tm ttm = tm();
    ttm.tm_year = yyyy - 1900; // Year since 1900
    ttm.tm_mon = mm - 1; // Month since January 
    ttm.tm_mday = dd; // Day of the month [1-31]
    ttm.tm_hour = HH; // Hour of the day [00-23]
    ttm.tm_min = MM;
    ttm.tm_sec = SS;

    time_t ttime_t = mktime(&ttm);

    system_clock::time_point time_point_result = std::chrono::system_clock::from_time_t(ttime_t);

    time_point_result += std::chrono::milliseconds(fff);
    return time_point_result;
}

std::string time_point_to_string(std::chrono::system_clock::time_point &tp)
{
    using namespace std;
    using namespace std::chrono;

    auto ttime_t = system_clock::to_time_t(tp);
    auto tp_sec = system_clock::from_time_t(ttime_t);
    milliseconds ms = duration_cast<milliseconds>(tp - tp_sec);

    std::tm * ttm = localtime(&ttime_t);

    char date_time_format[] = "%Y.%m.%d-%H.%M.%S";

    char time_str[] = "yyyy.mm.dd.HH-MM.SS.fff";

    strftime(time_str, strlen(time_str), date_time_format, ttm);

    string result(time_str);
    result.append(".");
    result.append(to_string(ms.count()));

    return result;
}

Bundler: Command not found

I had the exact same issue and was able to resolve it by running

rbenv rehash

After that bundle worked as expected. Upon taking a look at the rbenv wiki entry it does mention that rehash should be run when an installed gem provides commands.

Installs shims for all Ruby executables known to rbenv (i.e., ~/.rbenv/versions//bin/). Run this command after you install a new version of Ruby, or install a gem that provides commands.

Apparently this is such an annoyance that some folks have written a gem to make sure you never need to run rehash again. rbenv-gem-rehash

What is __future__ in Python used for and how/when to use it, and how it works

With __future__ module's inclusion, you can slowly be accustomed to incompatible changes or to such ones introducing new keywords.

E.g., for using context managers, you had to do from __future__ import with_statement in 2.5, as the with keyword was new and shouldn't be used as variable names any longer. In order to use with as a Python keyword in Python 2.5 or older, you will need to use the import from above.

Another example is

from __future__ import division
print 8/7  # prints 1.1428571428571428
print 8//7 # prints 1

Without the __future__ stuff, both print statements would print 1.

The internal difference is that without that import, / is mapped to the __div__() method, while with it, __truediv__() is used. (In any case, // calls __floordiv__().)

Apropos print: print becomes a function in 3.x, losing its special property as a keyword. So it is the other way round.

>>> print

>>> from __future__ import print_function
>>> print
<built-in function print>
>>>

Get div height with plain JavaScript

<div id="item">show taille height</div>
<script>
    alert(document.getElementById('item').offsetHeight);
</script>

Jsfiddle

How can I use pickle to save a dict?

import pickle

dictobj = {'Jack' : 123, 'John' : 456}

filename = "/foldername/filestore"

fileobj = open(filename, 'wb')

pickle.dump(dictobj, fileobj)

fileobj.close()

Settings to Windows Firewall to allow Docker for Windows to share drive

I found it quite easy. Just go to you network connections. You can go Control Panel/Network and Sharing. You will find various connections. Search for Docker connection. Select which ever is default. After selecting network, go to Properties. In the properties section enable the option Hyper-V Extensible Virtual Switch. This will help virtual container to use network card.

Jquery change <p> text programmatically

"saving" is something wholly different from changing paragraph content with jquery.

If you need to save changes you will have to write them to your server somehow (likely form submission along with all the security and input sanitizing that entails). If you have information that is saved on the server then you are no longer changing the content of a paragraph, you are drawing a paragraph with dynamic content (either from a database or a file which your server altered when you did the "saving").

Judging by your question, this is a topic on which you will have to do MUCH more research.

Input page (input.html):

<form action="/saveMyParagraph.php">
    <input name="pContent" type="text"></input>
</form>

Saving page (saveMyParagraph.php) and Ouput page (output.php):

Inserting Data Into a MySQL Database using PHP

Can we create an instance of an interface in Java?

Normaly, you can create a reference for an interface. But you cant create an instance for interface.

Performing Breadth First Search recursively

Here is a BFS recursive traversal Python implementation, working for a graph with no cycle.

def bfs_recursive(level):
    '''
     @params level: List<Node> containing the node for a specific level.
    '''
    next_level = []
    for node in level:
        print(node.value)
        for child_node in node.adjency_list:
            next_level.append(child_node)
    if len(next_level) != 0:
        bfs_recursive(next_level)


class Node:
    def __init__(self, value):
        self.value = value
        self.adjency_list = []

What is the difference between bottom-up and top-down?

Simply saying top down approach uses recursion for calling Sub problems again and again
where as bottom up approach use the single without calling any one and hence it is more efficient.

Get Current date in epoch from Unix shell script

Update: The answer previously posted here linked to a custom script that is no longer available, solely because the OP indicated that date +'%s' didn't work for him. Please see UberAlex' answer and cadrian's answer for proper solutions. In short:

  1. For the number of seconds since the Unix epoch use date(1) as follows:

    date +'%s'
    
  2. For the number of days since the Unix epoch divide the result by the number of seconds in a day (mind the double parentheses!):

    echo $(($(date +%s) / 60 / 60 / 24))
    

What does it mean when an HTTP request returns status code 0?

In my case, the error occurred in a page requested with HTTP protocol, with a Javascript inside it trying to make an HTTPS request. And vice-versa.

After page loading, press F12 (or Ctrl + U) and take a look at the HTML code of your page. If you see something like that in your code:

<!-- javascript request inside the page -->
<script>
var ajaxurl = "https://example.com/wp-admin/admin-ajax.php";
(...)
</script>

And your page was requested this way:

http://example.com/example-page/2019/09/13/my-post/#elf_l1_Lw

You certainly will face this error.

To fix it, set the protocol of the Javascript request equal to the protocol of page request.

This situation involving different protocols, for page and js requests, was mentioned before in the answer of Brad Parks but, I guess the diagnostic technique presented here is easier, for the majority of users.

Return value using String result=Command.ExecuteScalar() error occurs when result returns null

Use SQL server isnull function

public string absentDayNo(DateTime sdate, DateTime edate, string idemp)
{ 
    string result="0";
    string myQuery="select isnull(COUNT(idemp_atd),0) as absentDayNo from td_atd where ";
    myQuery +=" absentdate_atd between '"+sdate+"' and '"+edate+" ";
    myQuery +=" and idemp_atd='"+idemp+"' group by idemp_atd ";

    SqlCommand cmd = new SqlCommand(myQuery, conn);
    conn.Open();
    //System.NullReferenceException occurs when their is no data/result
    string getValue = cmd.ExecuteScalar().ToString();
    if (getValue != null)
    {
        result = getValue.ToString();
    }
    conn.Close();
    return result;
}

Is it possible to disable the network in iOS Simulator?

Since Xcode does not provide such feature, you will definitely go for some third party application/ tool. Turning off the MAC network will also help to turn off the iOS Simulator network.

You can turn off you MAC internet from "System Preferences..." > "Network" and turn off the desire network source.

To turnoff you MAC Ethernet internet source: EtherNet Network Source

To turnoff you MAC WiFi internet source(if your MAC is on Wifi Internet): enter image description here

Which port we can use to run IIS other than 80?

Port 8080 might have been used by another process in your computer.

Do netstat in command prompt to find out which server/process is using it.

Have a look at this page (http://en.wikipedia.org/wiki/Port_number) it gives you full explanation on how to use port number

How do I find the MySQL my.cnf location

mysql --help | grep /my.cnf | xargs ls

will tell you where my.cnf is located on Mac/Linux

ls: cannot access '/etc/my.cnf': No such file or directory
ls: cannot access '~/.my.cnf': No such file or directory
 /etc/mysql/my.cnf

In this case, it is in /etc/mysql/my.cnf

ls: /etc/my.cnf: No such file or directory
ls: /etc/mysql/my.cnf: No such file or directory
ls: ~/.my.cnf: No such file or directory
/usr/local/etc/my.cnf

In this case, it is in /usr/local/etc/my.cnf

how to split the ng-repeat data with three columns using bootstrap

I'm new in bootstrap and angularjs, but this could also make Array per 4 items as one group, the result will almost like 3 columns. This trick use bootstrap break line principle.

<div class="row">
 <div class="col-sm-4" data-ng-repeat="item in items">
  <div class="some-special-class">
   {{item.XX}}
  </div>
 </div>
</div>

Jquery select this + class

Use find()

$(this).find(".subclass").css("visibility","visible");

Is It Possible to NSLog C Structs (Like CGRect or CGPoint)?

There are a few functions like:

NSStringFromCGPoint  
NSStringFromCGSize  
NSStringFromCGRect  
NSStringFromCGAffineTransform  
NSStringFromUIEdgeInsets

An example:

NSLog(@"rect1: %@", NSStringFromCGRect(rect1));

fatal: Not a git repository (or any of the parent directories): .git

The command has to be entered in the directory of the repository. The error is complaining that your current directory isn't a git repo

  1. Are you in the right directory? Does typing ls show the right files?
  2. Have you initialized the repository yet? Typed git init? (git-init documentation)

Either of those would cause your error.

getResources().getColor() is deprecated

well it's deprecated in android M so you must make exception for android M and lower. Just add current theme on getColor function. You can get current theme with getTheme().

This will do the trick in fragment, you can replace getActivity() with getBaseContext(), yourContext, etc which hold your current context

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    yourTitle.setTextColor(getActivity().getResources().getColor(android.R.color.white, getActivity().getTheme()));
}else {
    yourTitle.setTextColor(getActivity().getResources().getColor(android.R.color.white));
}

*p.s : color is deprecated in M, but drawable is deprecated in L

Linux find file names with given string recursively

The find command will take long time because it scans real files in file system.

The quickest way is using locate command, which will give result immediately:

locate "John"

If the command is not found, you need to install mlocate package and run updatedb command first to prepare the search database for the first time.

More detail here: https://medium.com/@thucnc/the-fastest-way-to-find-files-by-filename-mlocate-locate-commands-55bf40b297ab

PHP cURL error code 60

The solution is to edit the file php.ini located in your php version(for me it's php7.0.10) not the php.ini of apache. You will find a commented file like this ;curl.cainfo Just change this line like this curl.cainfo = "C:\permCertificate\cacert.pem"

Don't forget to create the "permCertificate" directory and copy the "cacert.pem" file inside it.

Update TensorFlow

To upgrade any python package, use pip install <pkg_name> --upgrade.

So in your case it would be pip install tensorflow --upgrade. Just updated to 1.1.0

What is the right way to debug in iPython notebook?

In Python 3.7 you can use breakpoint() function. Just enter

breakpoint()

wherever you would like runtime to stop and from there you can use the same pdb commands (r, c, n, ...) or evaluate your variables.

What should I use to open a url instead of urlopen in urllib3

In urlip3 there's no .urlopen, instead try this:

import requests
html = requests.get(url)

Checkout one file from Subversion

If you just want to export the file, and you won't need to update it later, you can do it without having to use SVN commands.

Using TortoiseSVN Repository Browser, select the file, right click, and then select "Copy URL to clipboard". Paste that URL to your browser, and after login you should be prompted with the file download.

This way you can also select desired revision and download an older version of the file.

Note that this is valid if your SVN server has a web interface.

How to see my Eclipse version?

Go to the folder in which eclipse is installed then open readme folder followed by the readme txt file. Here you will find all the info you need.

What is time_t ultimately a typedef to?

Under Visual Studio 2008, it defaults to an __int64 unless you define _USE_32BIT_TIME_T. You're better off just pretending that you don't know what it's defined as, since it can (and will) change from platform to platform.

Add floating point value to android resources/values

All the solutions suggest you to use the predefined float value through code.

But in case you are wondering how to reference the predefined float value in XML (for example layouts), then following is an example of what I did and it's working perfectly:

Define resource values as type="integer" but format="float", for example:

<item name="windowWeightSum" type="integer" format="float">6.0</item>
<item name="windowNavPaneSum" type="integer" format="float">1.5</item>
<item name="windowContentPaneSum" type="integer" format="float">4.5</item>

And later use them in your layout using @integer/name_of_resource, for example:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:weightSum="@integer/windowWeightSum"                 // float 6.0
    android:orientation="horizontal">

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="@integer/windowNavPaneSum"        // float 1.5
        android:orientation="vertical">
        <!-- other views -->
    </LinearLayout>

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="@integer/windowContentPaneSum"    // float 4.5
        android:orientation="vertical">
        <!-- other views -->
    </LinearLayout>

</LinearLayout>

How to send email using simple SMTP commands via Gmail?

to send over gmail, you need to use an encrypted connection. this is not possible with telnet alone, but you can use tools like openssl

either connect using the starttls option in openssl to convert the plain connection to encrypted...

openssl s_client -starttls smtp -connect smtp.gmail.com:587 -crlf -ign_eof

or connect to a ssl sockect directly...

openssl s_client -connect smtp.gmail.com:465 -crlf -ign_eof

EHLO localhost

after that, authenticate to the server using the base64 encoded username/password

AUTH PLAIN AG15ZW1haWxAZ21haWwuY29tAG15cGFzc3dvcmQ=

to get this from the commandline:

echo -ne '\[email protected]\00password' | base64
AHVzZXJAZ21haWwuY29tAHBhc3N3b3Jk

then continue with "mail from:" like in your example

example session:

openssl s_client -connect smtp.gmail.com:465 -crlf -ign_eof
[... lots of openssl output ...]
220 mx.google.com ESMTP m46sm11546481eeh.9
EHLO localhost
250-mx.google.com at your service, [1.2.3.4]
250-SIZE 35882577
250-8BITMIME
250-AUTH LOGIN PLAIN XOAUTH
250 ENHANCEDSTATUSCODES
AUTH PLAIN AG5pY2UudHJ5QGdtYWlsLmNvbQBub2l0c25vdG15cGFzc3dvcmQ=
235 2.7.0 Accepted
MAIL FROM: <[email protected]>
250 2.1.0 OK m46sm11546481eeh.9
rcpt to: <[email protected]>
250 2.1.5 OK m46sm11546481eeh.9
DATA
354  Go ahead m46sm11546481eeh.9
Subject: it works

yay!
.
250 2.0.0 OK 1339757532 m46sm11546481eeh.9
quit
221 2.0.0 closing connection m46sm11546481eeh.9
read:errno=0

Import one schema into another new schema - Oracle

The issue was with the dmp file itself. I had to re-export the file and the command works fine. Thank you @Justin Cave

"elseif" syntax in JavaScript

You are missing a space between else and if

It should be else if instead of elseif

if(condition)
{

} 
else if(condition)
{

}
else
{

}

Getting a UnhandledPromiseRejectionWarning when testing using mocha/chai

For those who are looking for the error/warning UnhandledPromiseRejectionWarning outside of a testing environment, It could be probably because nobody in the code is taking care of the eventual error in a promise:

For instance, this code will show the warning reported in this question:

new Promise((resolve, reject) => {
  return reject('Error reason!');
});

(node:XXXX) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): Error: Error reason!

and adding the .catch() or handling the error should solve the warning/error

new Promise((resolve, reject) => {
  return reject('Error reason!');
}).catch(() => { /* do whatever you want here */ });

Or using the second parameter in the then function

new Promise((resolve, reject) => {
  return reject('Error reason!');
}).then(null, () => { /* do whatever you want here */ });

How to download Visual Studio 2017 Community Edition for offline installation?

Here you can download visual studio 2017 initial installer:

https://docs.microsoft.com/en-us/visualstudio/install/create-an-offline-installation-of-visual-studio?view=vs-2017

Run it and after few minutes it will ask what components do you want to install and in the right bottom there will be two option
"Install while downloading"
"Download all, then install"

Select any option and click install.

PHP foreach change original array values

Use &:

foreach($arr as &$value) {
    $value = $newVal;
}

& passes a value of the array as a reference and does not create a new instance of the variable. Thus if you change the reference the original value will change.

PHP documentation for Passing by Reference

Edit 2018

This answer seems to be favored by a lot of people on the internet, which is why I decided to add more information and words of caution.
While pass by reference in foreach (or functions) is a clean and short solution, for many beginners this might be a dangerous pitfall.

  1. Loops in PHP don't have their own scope. - @Mark Amery

    This could be a serious problem when the variables are being reused in the same scope. Another SO question nicely illustrates why that might be a problem.

  2. As foreach relies on the internal array pointer in PHP 5, changing it within the loop may lead to unexpected behavior. - PHP docs for foreach.

    Unsetting a record or changing the hash value (the key) during the iteration on the same loop could lead to potentially unexpected behaviors in PHP < 7. The issue gets even more complicated when the array itself is a reference.

  3. Foreach performance.
    In general, PHP prefers pass by value due to the copy-on-write feature. It means that internally PHP will not create duplicate data unless the copy of it needs to be changed. It is debatable whether pass by reference in foreach would offer a performance improvement. As it is always the case, you need to test your specific scenario and determine which option uses less memory and CPU time. For more information see the SO post linked below by NikiC.

  4. Code readability.
    Creating references in PHP is something that quickly gets out of hand. If you are a novice and don't have full control of what you are doing, it is best to stay away from references. For more information about & operator take a look at this guide: Reference — What does this symbol mean in PHP?
    For those who want to learn more about this part of PHP language: PHP References Explained

A very nice technical explanation by @NikiC of the internal logic of PHP foreach loops:
How does PHP 'foreach' actually work?

How can I scan barcodes on iOS?

We produced the 'Barcodes' application for the iPhone. It can decode QR Codes. The source code is available from the zxing project; specifically, you want to take a look at the iPhone client and the partial C++ port of the core library. The port is a little old, from circa the 0.9 release of the Java code, but should still work reasonably well.

If you need to scan other formats, like 1D formats, you could continue the port of the Java code within this project to C++.

EDIT: Barcodes and the iphone code in the project were retired around the start of 2014.

Python: 'break' outside loop

break breaks out of a loop, not an if statement, as others have pointed out. The motivation for this isn't too hard to see; think about code like

for item in some_iterable:
    ...
    if break_condition():
        break 

The break would be pretty useless if it terminated the if block rather than terminated the loop -- terminating a loop conditionally is the exact thing break is used for.

How to add Class in <li> using wp_nav_menu() in Wordpress?

None of these responses really seem to answer the question. Here's something similar to what I'm utilizing on a site of mine by targeting a menu item by its title/name:

function add_class_to_menu_item($sorted_menu_objects, $args) {
    $theme_location = 'primary_menu';  // Name, ID, or Slug of the target menu location
    $target_menu_title = 'Link';  // Name/Title of the menu item you want to target
    $class_to_add = 'my_own_class';  // Class you want to add

    if ($args->theme_location == $theme_location) {
        foreach ($sorted_menu_objects as $key => $menu_object) {
            if ($menu_object->title == $target_menu_title) {
                $menu_object->classes[] = $class_to_add;
                break; // Optional.  Leave if you're only targeting one specific menu item
            }
        }
    }

    return $sorted_menu_objects;
}
add_filter('wp_nav_menu_objects', 'add_class_to_menu_item', 10, 2);

How to convert hex strings to byte values in Java

String str[] = {"aa", "55"};

byte b[] = new byte[str.length];

for (int i = 0; i < str.length; i++) {
    b[i] = (byte) Integer.parseInt(str[i], 16);
}

Integer.parseInt(string, radix) converts a string into an integer, the radix paramter specifies the numeral system.

Use a radix of 16 if the string represents a hexadecimal number.
Use a radix of 2 if the string represents a binary number.
Use a radix of 10 (or omit the radix paramter) if the string represents a decimal number.

For further details check the Java docs: https://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html#parseInt(java.lang.String,%20int)

fix java.net.SocketTimeoutException: Read timed out

I don't think it's enough merely to get the response. I think you need to read it (get the entity and read it via EntityUtils.consume()).

e.g. (from the doc)

     System.out.println("<< Response: " + response.getStatusLine());
     System.out.println(EntityUtils.toString(response.getEntity()));

How to disable Python warnings?

This is an old question but there is some newer guidance in PEP 565 that to turn off all warnings if you're writing a python application you should use:

import sys
import warnings

if not sys.warnoptions:
    warnings.simplefilter("ignore")

The reason this is recommended is that it turns off all warnings by default but crucially allows them to be switched back on via python -W on the command line or PYTHONWARNINGS.

Rails select helper - Default selected value, how?

<%= f.select :project_id, options_from_collection_for_select(@project_select,) %>

How do I properly escape quotes inside HTML attributes?

You really should only allow untrusted data into a whitelist of good attributes like: align, alink, alt, bgcolor, border, cellpadding, cellspacing, class, color, cols, colspan, coords, dir, face, height, hspace, ismap, lang, marginheight, marginwidth, multiple, nohref, noresize, noshade, nowrap, ref, rel, rev, rows, rowspan, scrolling, shape, span, summary, tabindex, title, usemap, valign, value, vlink, vspace, width

You really want to keep untrusted data out of javascript handlers as well as id or name attributes (they can clobber other elements in the DOM).

Also, if you are putting untrusted data into a SRC or HREF attribute, then its really a untrusted URL so you should validate the URL, make sure its NOT a javascript: URL, and then HTML entity encode.

More details on all of there here: https://www.owasp.org/index.php/Abridged_XSS_Prevention_Cheat_Sheet

Makefile, header dependencies

This will do the job just fine , and even handle subdirs being specified:

    $(CC) $(CFLAGS) -MD -o $@ $<

tested it with gcc 4.8.3

Count cells that contain any text

Sample file

enter image description here

Note:

  • Tried to find the formula for counting non-blank cells (="" is a blank cell) without a need to use data twice. The solution for : =ARRAYFORMULA(SUM(IFERROR(IF(data="",0,1),1))). For ={SUM(IFERROR(IF(data="",0,1),1))} should work (press Ctrl+Shift+Enter in the formula).

how to call service method from ng-change of select in angularjs?

You have at least two issues in your code:

  • ng-change="getScoreData(Score)

    Angular doesn't see getScoreData method that refers to defined service

  • getScoreData: function (Score, callback)

    We don't need to use callback since GET returns promise. Use then instead.

Here is a working example (I used random address only for simulation):

HTML

<select ng-model="score"
        ng-change="getScoreData(score)" 
        ng-options="score as score.name for score in  scores"></select>
    <pre>{{ScoreData|json}}</pre> 

JS

var fessmodule = angular.module('myModule', ['ngResource']);

fessmodule.controller('fessCntrl', function($scope, ScoreDataService) {

    $scope.scores = [{
        name: 'Bukit Batok Street 1',
        URL: 'http://maps.googleapis.com/maps/api/geocode/json?address=Singapore, SG, Singapore, 153 Bukit Batok Street 1&sensor=true'
    }, {
        name: 'London 8',
        URL: 'http://maps.googleapis.com/maps/api/geocode/json?address=Singapore, SG, Singapore, London 8&sensor=true'
    }];

    $scope.getScoreData = function(score) {
        ScoreDataService.getScoreData(score).then(function(result) {
            $scope.ScoreData = result;
        }, function(result) {
            alert("Error: No data returned");
        });
    };

});

fessmodule.$inject = ['$scope', 'ScoreDataService'];

fessmodule.factory('ScoreDataService', ['$http', '$q', function($http) {

    var factory = {
        getScoreData: function(score) {
            console.log(score);
            var data = $http({
                method: 'GET',
                url: score.URL
            });


            return data;
        }
    }
    return factory;
}]);

Demo Fiddle

range() for floats

A simpler library-less version

Aw, heck -- I'll toss in a simple library-less version. Feel free to improve on it[*]:

def frange(start=0, stop=1, jump=0.1):
    nsteps = int((stop-start)/jump)
    dy = stop-start
    # f(i) goes from start to stop as i goes from 0 to nsteps
    return [start + float(i)*dy/nsteps for i in range(nsteps)]

The core idea is that nsteps is the number of steps to get you from start to stop and range(nsteps) always emits integers so there's no loss of accuracy. The final step is to map [0..nsteps] linearly onto [start..stop].

edit

If, like alancalvitti you'd like the series to have exact rational representation, you can always use Fractions:

from fractions import Fraction

def rrange(start=0, stop=1, jump=0.1):
    nsteps = int((stop-start)/jump)
    return [Fraction(i, nsteps) for i in range(nsteps)]

[*] In particular, frange() returns a list, not a generator. But it sufficed for my needs.

Changing the width of Bootstrap popover

On Bootstrap 4, you can easily review the template option, by overriding the max-width :

$('#myButton').popover({
    placement: 'bottom',
    html: true,
    trigger: 'click',
    template: '<div class="popover" style="max-width: 500px;" role="tooltip"><div class="arrow"></div><h3 class="popover-header"></h3><div class="popover-body"></div></div>'
});

This is a good solution if you have several popovers on page.

How to check if a service is running via batch file and start it, if it is not running?

You can use the following command to see if a service is running or not:

sc query [ServiceName] | findstr /i "STATE"

When I run it for my NOD32 Antivirus, I get:

STATE                       : 4 RUNNING

If it was stopped, I would get:

STATE                       : 1 STOPPED

You can use this in a variable to then determine whether you use NET START or not.

The service name should be the service name, not the display name.

SQL time difference between two dates result in hh:mm:ss

While maybe not the most efficient, this would work:

declare @StartDate datetime, @EndDate datetime

select @StartDate = '10/01/2012 08:40:18.000',@EndDate='10/04/2012 09:52:48.000'

select convert(varchar(5),DateDiff(s, @startDate, @EndDate)/3600)+':'+convert(varchar(5),DateDiff(s, @startDate, @EndDate)%3600/60)+':'+convert(varchar(5),(DateDiff(s, @startDate, @EndDate)%60))

if you can run two selects then this would be better because you only do the datediff once:

declare @StartDate datetime, @EndDate datetime

select @StartDate = '10/01/2012 08:40:18.000',@EndDate='10/04/2012 09:52:48.000'
declare @Sec BIGINT

select @Sec = DateDiff(s, @startDate, @EndDate)

select convert(varchar(5),@sec/3600)+':'+convert(varchar(5),@sec%3600/60)+':'+convert(varchar(5),(@sec%60))

Capture iOS Simulator video for App Preview

In my MBP's Settings > Displays > Display, I see a setting for 'Resolution: Default for Display / Scaled'. I set it to 'More space', then try the various simulators, all of which seem to fit on the enlarged screen at 100%. I suspect that wouldn't work with your FullHD screen though...

An alternative might be to try to install some sort of VNC server solution on the simulator, like https://github.com/wingify/vnc, and record that with a VNC recorder - I believe there's a Python VNC recorder out there.

How to get a list of current open windows/process with Java?

The only way I can think of doing it is by invoking a command line application that does the job for you and then screenscraping the output (like Linux's ps and Window's tasklist).

Unfortunately, that'll mean you'll have to write some parsing routines to read the data from both.

Process proc = Runtime.getRuntime().exec ("tasklist.exe");
InputStream procOutput = proc.getInputStream ();
if (0 == proc.waitFor ()) {
    // TODO scan the procOutput for your data
}

How to convert SSH keypairs generated using PuTTYgen (Windows) into key-pairs used by ssh-agent and Keychain (Linux)

Newer versions of PuTTYgen (mine is 0.64) are able to show the OpenSSH public key to be pasted in the linux system in the .ssh/authorized_keys file, as shown in the following image:

enter image description here

Pointer to incomplete class type is not allowed

Check out if you are missing some import.

Check if inputs are empty using jQuery

how come nobody mentioned

$(this).filter('[value=]').addClass('warning');

seems more jquery-like to me

Error Importing SSL certificate : Not an X.509 Certificate

Does your cacerts.pem file hold a single certificate? Since it is a PEM, have a look at it (with a text editor), it should start with

-----BEGIN CERTIFICATE-----

and end with

-----END CERTIFICATE-----

Finally, to check it is not corrupted, get hold of openssl and print its details using

openssl x509 -in cacerts.pem -text

SQL Server: the maximum number of rows in table

We overflowed an integer primary key once (which is ~2.4 billion rows) on a table. If there's a row limit, you're not likely to ever hit it at a mere 36 million rows per year.

Search text in stored procedure in SQL Server

SELECT DISTINCT 
   o.name AS Object_Name,
   o.type_desc
FROM sys.sql_modules m        INNER JOIN        sys.objects o 
     ON m.object_id = o.object_id WHERE m.definition Like '%[String]%';

A more useful statusline in vim?

Here's mine:

set statusline=
set statusline +=%1*\ %n\ %*            "buffer number
set statusline +=%5*%{&ff}%*            "file format
set statusline +=%3*%y%*                "file type
set statusline +=%4*\ %<%F%*            "full path
set statusline +=%2*%m%*                "modified flag
set statusline +=%1*%=%5l%*             "current line
set statusline +=%2*/%L%*               "total lines
set statusline +=%1*%4v\ %*             "virtual column number
set statusline +=%2*0x%04B\ %*          "character under cursor

vim statusline

And here's the colors I used:

hi User1 guifg=#eea040 guibg=#222222
hi User2 guifg=#dd3333 guibg=#222222
hi User3 guifg=#ff66ff guibg=#222222
hi User4 guifg=#a0ee40 guibg=#222222
hi User5 guifg=#eeee40 guibg=#222222

How to add a “readonly” attribute to an <input>?

jQuery <1.9

$('#inputId').attr('readonly', true);

jQuery 1.9+

$('#inputId').prop('readonly', true);

Read more about difference between prop and attr

org.glassfish.jersey.servlet.ServletContainer ClassNotFoundException

It's an eclipse setup issue, not a Jersey issue.

From this thread ClassNotFoundException: org.glassfish.jersey.servlet.ServletContainer

Right click your eclipse project Properties -> Deployment Assembly -> Add -> Java Build Path Entries -> Gradle Dependencies -> Finish.

So Eclipse wasn't using the Gradle dependencies when Apache was starting .

Hashing a dictionary?

Answers from this thread with the highest upvotes didn't work for me as their hashing functions give different results on different machines due to PYTHOPYTHONHASHSEED.

I adjusted all the hints from this thread and came up with a solution that works for me.

import collections
import hashlib
import json


def simplify_object(o):
    if isinstance(o, dict):
        ordered_dict = collections.OrderedDict(sorted(o.items()))
        for k, v in ordered_dict.items():
            v = simplify_object(v)
            ordered_dict[str(k)] = v
        o = ordered_dict
    elif isinstance(o, (list, tuple, set)):
        o = [simplify_object(el) for el in o]
    else:
        o = str(o).strip()
    return o


def make_hash(o):
    o = simplify_object(o)
    bytes_val = json.dumps(o, sort_keys=True, ensure_ascii=True, default=str)
    hash_val = hashlib.sha1(bytes_val.encode()).hexdigest()
    return hash_val

'xmlParseEntityRef: no name' warnings while loading xml into a php file

Try to clean the HTML first using this function:

$html = htmlspecialchars($html);

Special chars are usually represented differently in HTML and it might be confusing for the compiler. Like & becomes &amp;.

Detecting IE11 using CSS Capability/Feature Detection

You can use js and add a class in html to maintain the standard of conditional comments:

  var ua = navigator.userAgent,
      doc = document.documentElement;

  if ((ua.match(/MSIE 10.0/i))) {
    doc.className = doc.className + " ie10";

  } else if((ua.match(/rv:11.0/i))){
    doc.className = doc.className + " ie11";
  }

Or use a lib like bowser:

https://github.com/ded/bowser

Or modernizr for feature detection:

http://modernizr.com/

python requests get cookies

Alternatively, you can use requests.Session and observe cookies before and after a request:

>>> import requests
>>> session = requests.Session()
>>> print(session.cookies.get_dict())
{}
>>> response = session.get('http://google.com')
>>> print(session.cookies.get_dict())
{'PREF': 'ID=5514c728c9215a9a:FF=0:TM=1406958091:LM=1406958091:S=KfAG0U9jYhrB0XNf', 'NID': '67=TVMYiq2wLMNvJi5SiaONeIQVNqxSc2RAwVrCnuYgTQYAHIZAGESHHPL0xsyM9EMpluLDQgaj3db_V37NjvshV-eoQdA8u43M8UwHMqZdL-S2gjho8j0-Fe1XuH5wYr9v'}

jQuery DIV click, with anchors

Using a custom url attribute makes the HTML invalid. Although that may not be a huge problem, the given examples are neither accessible. Not for keyboard navigation and not in cases when JavaScript is turned off (or blocked by some other script). Even Google will not find the page located at the specified url, not via this route at least.

It's quite easy to make this accessible though. Just make sure there's a regular link inside the div that points to the url. Using JavaScript/jQuery you add an onclick to the div that redirects to the location specified by the link's href attribute. Now, when JavaScript doesn't work, the link still does and it can even catch the focus when using the keyboard to navigate (and you don't need custom attributes, so your HTML can be valid).


I wrote a jQuery plugin some time ago that does this. It also adds classNames to the div (or any other element you want to make clickable) and the link so you can alter their looks with CSS when the div is indeed clickable. It even adds classNames that you can use to specify hover and focus styles.

All you need to do is specify the element(s) you want to make clickable and call their clickable() method: in your case that would be $("div.clickable).clickable();

For downloading + documentation see the plugin's page: jQuery: clickable — jLix

jQuery: get parent, parent id?

 $(this).closest('ul').attr('id');

Measuring code execution time

Stopwatch is designed for this purpose and is one of the best way to measure execution time in .NET.

var watch = System.Diagnostics.Stopwatch.StartNew();
/* the code that you want to measure comes here */
watch.Stop();
var elapsedMs = watch.ElapsedMilliseconds;

Do not use DateTimes to measure execution time in .NET.

Reading inputStream using BufferedReader.readLine() is too slow

I strongly suspect that's because of the network connection or the web server you're talking to - it's not BufferedReader's fault. Try measuring this:

InputStream stream = conn.getInputStream();
byte[] buffer = new byte[1000];
// Start timing
while (stream.read(buffer) > 0)
{
}
// End timing

I think you'll find it's almost exactly the same time as when you're parsing the text.

Note that you should also give InputStreamReader an appropriate encoding - the platform default encoding is almost certainly not what you should be using.

Finding three elements in an array whose sum is closest to a given number

Here is the C++ code:

bool FindSumZero(int a[], int n, int& x, int& y, int& z)
{
    if (n < 3)
        return false;

    sort(a, a+n);

    for (int i = 0; i < n-2; ++i)
    {
        int j = i+1;
        int k = n-1;

        while (k >= j)
        {
            int s = a[i]+a[j]+a[k];

            if (s == 0 && i != j && j != k && k != i)
            {
                x = a[i], y = a[j], z = a[k];
                return true;
            }

            if (s > 0)
                --k;
            else
                ++j;
        }
    }

    return false;
}

IE11 prevents ActiveX from running

In my IE11, works normally. Version: 11.306.10586.0

We can test if ActiveX works at IE, in this site: http://www.pcpitstop.com/testax.asp

What's the difference between session.persist() and session.save() in Hibernate?

Here is the difference:

  1. save:

    1. will return the id/identifier when the object is saved to the database.
    2. will also save when the object is tried to do the same by opening a new session after it is detached.
  2. Persist:

    1. will return void when the object is saved to the database.
    2. will throw PersistentObjectException when tried to save the detached object through a new session.

Difference between $(this) and event.target?

There are cross browser issues here.

A typical non-jQuery event handler would be something like this :

function doSomething(evt) {
    evt = evt || window.event;
    var target = evt.target || evt.srcElement;
    if (target.nodeType == 3) // defeat Safari bug
        target = target.parentNode;
    //do stuff here
}

jQuery normalises evt and makes the target available as this in event handlers, so a typical jQuery event handler would be something like this :

function doSomething(evt) {
    var $target = $(this);
    //do stuff here
}

A hybrid event handler which uses jQuery's normalised evt and a POJS target would be something like this :

function doSomething(evt) {
    var target = evt.target || evt.srcElement;
    if (target.nodeType == 3) // defeat Safari bug
        target = target.parentNode;
    //do stuff here
}

How to trigger a click on a link using jQuery

For links this should work:

eval($(selector).attr('href'));

How to connect html pages to mysql database?

HTML are markup languages, basically they are set of tags like <html>, <body>, which is used to present a website using , and as a whole. All these, happen in the clients system or the user you will be browsing the website.

Now, Connecting to a database, happens on whole another level. It happens on server, which is where the website is hosted.

So, in order to connect to the database and perform various data related actions, you have to use server-side scripts, like , , etc.

Now, lets see a snippet of connection using MYSQLi Extension of PHP

$db = mysqli_connect('hostname','username','password','databasename');

This single line code, is enough to get you started, you can mix such code, combined with HTML tags to create a HTML page, which is show data based pages. For example:

<?php
    $db = mysqli_connect('hostname','username','password','databasename');
?>
<html>
    <body>
          <?php
                $query = "SELECT * FROM `mytable`;";
                $result = mysqli_query($db, $query);
                while($row = mysqli_fetch_assoc($result)) {
                      // Display your datas on the page
                }
          ?>
    </body>
</html>

In order to insert new data into the database, you can use phpMyAdmin or write a INSERT query and execute them.

Can I access a form in the controller?

Bit late for an answer but came with following option. It is working for me but not sure if it is the correct way or not.

In my view I'm doing this:

<form name="formName">
    <div ng-init="setForm(formName);"></div>
</form>

And in the controller:

$scope.setForm = function (form) {
    $scope.myForm = form;
}

Now after doing this I have got my form in my controller variable which is $scope.myForm

PHPExcel set border and format for all sheets in spreadsheet

for ($s=65; $s<=90; $s++) {
    //echo chr($s);
    $objPHPExcel->getActiveSheet()->getColumnDimension(chr($s))->setAutoSize(true);
}

Reading an Excel file in python using pandas

Here is an updated method with syntax that is more common in python code. It also prevents you from opening the same file multiple times.

import pandas as pd

sheet1, sheet2 = None, None
with pd.ExcelFile("PATH\FileName.xlsx") as reader:
    sheet1 = pd.read_excel(reader, sheet_name='Sheet1')
    sheet2 = pd.read_excel(reader, sheet_name='Sheet2')

https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_excel.html

How to change the style of the title attribute inside an anchor tag?

It seems that there is in fact a pure CSS solution, requiring only the css attr expression, generated content and attribute selectors (which suggests that it works as far back as IE8):

https://jsfiddle.net/z42r2vv0/2/

_x000D_
_x000D_
a {
  position: relative;
  display: inline-block;
  margin-top: 20px;
}

a[title]:hover::after {
  content: attr(title);
  position: absolute;
  top: -100%;
  left: 0;
}
_x000D_
<a href="http://www.google.com/" title="Hello world!">
  Hover over me
</a>
_x000D_
_x000D_
_x000D_

update w/ input from @ViROscar: please note that it's not necessary to use any specific attribute, although I've used the "title" attribute in the example above; actually my recommendation would be to use the "alt" attribute, as there is some chance that the content will be accessible to users unable to benefit from CSS.

update again I'm not changing the code because the "title" attribute has basically come to mean the "tooltip" attribute, and it's probably not a good idea to hide important text inside a field only accessible on hover, but if you're interested in making this text accessible the "aria-label" attribute seems like the best place for it: https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/ARIA_Techniques/Using_the_aria-label_attribute

how to create dynamic two dimensional array in java?

Here is a simple example. this method will return a 2 dimensional tType array

public tType[][] allocate(Class<tType> c,int row,int column){
        tType [][] matrix = (tType[][]) Array.newInstance(c,row);
        for (int i = 0; i < column; i++) {
            matrix[i] = (tType[]) Array.newInstance(c,column);
        }
        return matrix;

    }

say you want a 2 dimensional String array, then call this function as

String [][] stringArray = allocate(String.class,3,3);

This will give you a two dimensional String array with 3 rows and 3 columns; Note that in Class<tType> c -> c cannot be primitive type like say, int or char or double. It must be non-primitive like, String or Double or Integer and so on.

How do you modify the web.config appSettings at runtime?

You need to use WebConfigurationManager.OpenWebConfiguration(): For Example:

Dim myConfiguration As Configuration = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("~")
myConfiguration.ConnectionStrings.ConnectionStrings("myDatabaseName").ConnectionString = txtConnectionString.Text
myConfiguration.AppSettings.Settings.Item("myKey").Value = txtmyKey.Text
myConfiguration.Save()

I think you might also need to set AllowLocation in machine.config. This is a boolean value that indicates whether individual pages can be configured using the element. If the "allowLocation" is false, it cannot be configured in individual elements.

Finally, it makes a difference if you run your application in IIS and run your test sample from Visual Studio. The ASP.NET process identity is the IIS account, ASPNET or NETWORK SERVICES (depending on IIS version).

Might need to grant ASPNET or NETWORK SERVICES Modify access on the folder where web.config resides.

GridView - Show headers on empty data source

Use an EmptyDataTemplate like below. When your DataSource has no records, you will see your grid with headers, and the literal text or HTML that is inside the EmptyDataTemplate tags.

<asp:GridView ID="gvResults" AutoGenerateColumns="False" HeaderStyle-CssClass="tableheader" runat="server">
    <EmptyDataTemplate>
        <asp:Label ID="lblEmptySearch" runat="server">No Results Found</asp:Label>
    </EmptyDataTemplate>
    <Columns>
        <asp:BoundField DataField="ItemId" HeaderText="ID" />
        <asp:BoundField DataField="Description" HeaderText="Description" />
        ...
    </Columns>
</asp:GridView>

Check whether variable is number or string in JavaScript

Simple and thorough:

function isNumber(x) {
  return parseFloat(x) == x
};

Test cases:

console.log('***TRUE CASES***');
console.log(isNumber(0));
console.log(isNumber(-1));
console.log(isNumber(-500));
console.log(isNumber(15000));
console.log(isNumber(0.35));
console.log(isNumber(-10.35));
console.log(isNumber(2.534e25));
console.log(isNumber('2.534e25'));
console.log(isNumber('52334'));
console.log(isNumber('-234'));
console.log(isNumber(Infinity));
console.log(isNumber(-Infinity));
console.log(isNumber('Infinity'));
console.log(isNumber('-Infinity'));

console.log('***FALSE CASES***');
console.log(isNumber(NaN));
console.log(isNumber({}));
console.log(isNumber([]));
console.log(isNumber(''));
console.log(isNumber('one'));
console.log(isNumber(true));
console.log(isNumber(false));
console.log(isNumber());
console.log(isNumber(undefined));
console.log(isNumber(null));
console.log(isNumber('-234aa'));

How to resolve Nodejs: Error: ENOENT: no such file or directory

[this is a helpful link on multer github][1]

but for me i have to create a public folder in the server folder also its like -cb(null,'public/'). [1]: https://github.com/expressjs/multer/issues/513

Simple way to unzip a .zip file using zlib

zlib handles the deflate compression/decompression algorithm, but there is more than that in a ZIP file.

You can try libzip. It is free, portable and easy to use.

UPDATE: Here I attach quick'n'dirty example of libzip, with all the error controls ommited:

#include <zip.h>

int main()
{
    //Open the ZIP archive
    int err = 0;
    zip *z = zip_open("foo.zip", 0, &err);

    //Search for the file of given name
    const char *name = "file.txt";
    struct zip_stat st;
    zip_stat_init(&st);
    zip_stat(z, name, 0, &st);

    //Alloc memory for its uncompressed contents
    char *contents = new char[st.size];

    //Read the compressed file
    zip_file *f = zip_fopen(z, name, 0);
    zip_fread(f, contents, st.size);
    zip_fclose(f);

    //And close the archive
    zip_close(z);

    //Do something with the contents
    //delete allocated memory
    delete[] contents;
}

Submitting a form by pressing enter without a submit button

IE doesn't allow pressing the ENTER key for form submission if the submit button is not visible, and the form has more than one field. Give it what it wants by providing a 1x1 pixel transparent image as a submit button. Of course it will take up a pixel of the layout, but look what you have to do to hide it.

<input type="image" src="img/1x1trans.gif"/>

How to substitute shell variables in complex text files

If you want env variables to be replaced in your source files while keeping all of the non env variables as they are, you can use the following command:

envsubst "$(printf '${%s} ' $(env | sed 's/=.*//'))" < source.txt > destination.txt

The syntax for replacing only specific variables is explained here. The command above is using a sub-shell to list all defined variables and then passing it to the envsubst

So if there's a defined env variable called $NAME, and your source.txt file looks like this:

Hello $NAME
Your balance is 123 ($USD)

The destination.txt will be:

Hello Arik
Your balance is 123 ($USD)

Notice that the $NAME is replaced and the $USD is left untouched