Programs & Examples On #Sccm 2007

How do I convert a String object into a Hash object?

For different string, you can do it without using dangerous eval method:

hash_as_string = "{\"0\"=>{\"answer\"=>\"1\", \"value\"=>\"No\"}, \"1\"=>{\"answer\"=>\"2\", \"value\"=>\"Yes\"}, \"2\"=>{\"answer\"=>\"3\", \"value\"=>\"No\"}, \"3\"=>{\"answer\"=>\"4\", \"value\"=>\"1\"}, \"4\"=>{\"value\"=>\"2\"}, \"5\"=>{\"value\"=>\"3\"}, \"6\"=>{\"value\"=>\"4\"}}"
JSON.parse hash_as_string.gsub('=>', ':')

Change the background color in a twitter bootstrap modal?

remove bootstrap modal background try this one

.modal-backdrop {
   background: none;

Handling key-press events (F1-F12) using JavaScript and jQuery, cross-browser

I am not sure if intercepting function keys is possible, but I would avoid using function keys all together. Function keys are used by browsers to perform a variety of tasks, some of them quite common. For example, in Firefox on Linux, at least six or seven of the function keys are reserved for use by the browser:

  • F1 (Help),
  • F3 (Search),
  • F5 (Refresh),
  • F6 (focus address bar),
  • F7 (caret browsing mode),
  • F11 (full screen mode), and
  • F12 (used by several add-ons, including Firebug)

The worst part is that different browsers on different operating systems use different keys for different things. That's a lot of differences to account for. You should stick to safer, less commonly used key combinations.

Collections.emptyList() returns a List<Object>?

Since Java 8 this kind of code compiles as expected and the type parameter gets inferred by the compiler.

public Person(String name) {
    this(name, Collections.emptyList()); // Inferred to List<String> in Java 8

public Person(String name, List<String> nicknames) { = name;
    this.nicknames = nicknames;

The new thing in Java 8 is that the target type of an expression will be used to infer type parameters of its sub-expressions. Before Java 8 only direct assignments and arguments to methods where used for type parameter inference.

In this case the parameter type of the constructor will be the target type for Collections.emptyList(), and the return value type will get chosen to match the parameter type.

This mechanism was added in Java 8 mainly to be able to compile lambda expressions, but it improves type inferences generally.

Java is getting closer to proper Hindley–Milner type inference with every release!

Password must have at least one non-alpha character

A simple method will be like this:

Match match1 = Regex.Match(<input_string>, @"(?=.{7})");   

match1.Success ensures that there are at least 8 characters.

Match match2 = Regex.Match(<input_string>, [^a-zA-Z]);

match2.Success ensures that there is at least one special character or number within the string.

So, match1.Success && match2.Success guarantees will get what you want.

Authentication failed because remote party has closed the transport stream

using (var client = new HttpClient(handler))
                ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;
                var response = await client.SendAsync(new HttpRequestMessage(HttpMethod.Get, apiEndPoint)).ConfigureAwait(false);
                await response.Content.ReadAsStringAsync().ConfigureAwait(false);

This worked for me

Creating pdf files at runtime in c#

I have used (iTextSharp) in the past with nice results.

jQuery hide and show toggle div with plus and minus icon

Toggle the text Show and Hide and move your backgroundPosition Y axis


$(function(){ // DOM READY shorthand


    $('.show_hide').click(function( e ){
        // e.preventDefault(); // If you use anchors
        var SH = this.SH^=1; // "Simple toggler"
               .css({backgroundPosition:'0 '+ (SH?-18:0) +'px'})



  background:url(plusminus.png) no-repeat;

How to cast from List<Double> to double[] in Java?

You can use primitive collections from Eclipse Collections and avoid boxing altogether.

DoubleList frameList = DoubleLists.mutable.empty();
double[] arr = frameList.toArray();

If you can't or don't want to initialize a DoubleList:

List<Double> frames = new ArrayList<>();
double[] arr = ListAdapter.adapt(frames).asLazy().collectDouble(each -> each).toArray();

Note: I am a contributor to Eclipse Collections.

Batch file include external file for variables

So you just have to do this right?:

@echo off
echo text shizzle
echo pause^>nul (press enter)

REM writing to file
echo XD
echo LOL

REM setting the variables out of the file
set /p input=
set /p input2=

REM echo'ing the variables
echo variables:
echo %input%
echo %input2%

if %input%==XD goto newecho
DEL settings.cdb

echo If you can see this, good job!
DEL settings.cdb

Convert NSData to String?


You can use (see NSString Class Reference)

- (id)initWithData:(NSData *)data encoding:(NSStringEncoding)encoding


NSString *myString = [[NSString alloc] initWithData:myData encoding:NSUTF8StringEncoding];

Remark: Please notice the NSData value must be valid for the encoding specified (UTF-8 in the example above), otherwise nil will be returned:

Returns nil if the initialization fails for some reason (for example if data does not represent valid data for encoding).

Prior Swift 3.0

String(data: yourData, encoding: NSUTF8StringEncoding)

Swift 3.0 Onwards

String(data: yourData, encoding: .utf8)

See String#init(data:encoding:) Reference

How to print the value of a Tensor object in TensorFlow?

Try this simple code! (it is self explanatory)

import tensorflow as tf
sess = tf.InteractiveSession() # see the answers above :)
x = [[1.,2.,1.],[1.,1.,1.]]    # a 2D matrix as input to softmax
y = tf.nn.softmax(x)           # this is the softmax function
                               # you can have anything you like here
u = y.eval()

Loading local JSON file

If you're looking for something quick and dirty just load the data in the head of your HTML document.


var DATA = {"a" : "b", "c" : "d"};


   <script src="data.js" ></script>
   <script src="main.js" ></script>


   console.log(DATA); // {"a" : "b", "c" : "d"}

I should mention that your heap size (in Chrome) is about 4GBs, so if your data is larger than that you should find another method. If you want to check another browser try this:

window.performance.memory.jsHeapSizeLimit / 1024 / 1024 / 1024 + " GBs"
// "4.046875 GBs"

How to insert an item into a key/value pair object?

I would use the Dictionary<TKey, TValue> (so long as each key is unique).

EDIT: Sorry, realised you wanted to add it to a specific position. My bad. You could use a SortedDictionary but this still won't let you insert.

Using Vim's tabs like buffers

  • You can map commands that normally manipulate buffers to manipulate tabs, as I've done with gf in my .vimrc:

    map gf :tabe <cfile><CR>

    I'm sure you can do the same with [^

  • I don't think vim supports this for tabs (yet). I use gt and gT to move to the next and previous tabs, respectively. You can also use Ngt, where N is the tab number. One peeve I have is that, by default, the tab number is not displayed in the tab line. To fix this, I put a couple functions at the end of my .vimrc file (I didn't paste here because it's long and didn't format correctly).

Is there a difference between using a dict literal and a dict constructor?

I find the dict literal d = {'one': '1'} to be much more readable, your defining data, rather than assigning things values and sending them to the dict() constructor.

On the other hand i have seen people mistype the dict literal as d = {'one', '1'} which in modern python 2.7+ will create a set.

Despite this i still prefer to all-ways use the set literal because i think its more readable, personal preference i suppose.

How to list imported modules?

import sys

An approximation of getting all imports for the current module only would be to inspect globals() for modules:

import types
def imports():
    for name, val in globals().items():
        if isinstance(val, types.ModuleType):
            yield val.__name__

This won't return local imports, or non-module imports like from x import y. Note that this returns val.__name__ so you get the original module name if you used import module as alias; yield name instead if you want the alias.

Entity Framework Core add unique constraint code-first

On EF core you cannot create Indexes using data annotations.But you can do it using the Fluent API.

Like this inside your {Db}Context.cs:

protected override void OnModelCreating(ModelBuilder builder)
        .HasIndex(u => u.Email)

...or if you're using the overload with the buildAction:

protected override void OnModelCreating(ModelBuilder builder)
    builder.Entity<User>(entity => {
        entity.HasIndex(e => e.Email).IsUnique();

You can read more about it here : Indexes

Full Screen Theme for AppCompat

It should be parent="@style/Theme.AppCompat.Light.NoActionBar"

<style name="Theme.AppCompat.Light.NoActionBar.FullScreen" 
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowActionBar">false</item>
    <item name="android:windowFullscreen">true</item>
    <item name="android:windowContentOverlay">@null</item>

Read response headers from API response - Angular 5 + TypeScript

Angular 7 Service: + '/my-operation',body, { headers: headers, observe: 'response'});
          (res: HttpResponse) => {
                }  ,
        error =>{

python numpy machine epsilon

An easier way to get the machine epsilon for a given float type is to use np.finfo():

# 2.22044604925e-16

# 1.19209e-07

Java Desktop application: SWT vs. Swing

An important thing to consider is that some users and some resellers (Dell) install a 64 bit VM on their 64 bit Windows, and you can't use the same SWT library on 32 bit and 64 bit VMs.

This means you will need to distribute and test different packages depending on whether users have 32-bit or a 64-bit Java VM. See this problem with Azureus, for instance, but you also have it with Eclipse, where as of today the builds on the front download page do not run on a 64 bit VM.

How can I merge two MySQL tables?

If you need to do it manually, one time:

First, merge in a temporary table, with something like:

create table MERGED as select * from table 1 UNION select * from table 2

Then, identify the primary key constraints with something like


Where PK is the primary key field...

Solve the duplicates.

Rename the table.

[edited - removed brackets in the UNION query, which was causing the error in the comment below]

'Conda' is not recognized as internal or external command

I have just launched anaconda-navigator and run the conda commands from there.

Regular vs Context Free Grammars

The difference between regular and context free grammar: (N, S, P, S) : terminals, nonterminals, productions, starting state Terminal symbols

? elementary symbols of the language defined by a formal grammar

? abc

Nonterminal symbols (or syntactic variables)

? replaced by groups of terminal symbols according to the production rules


regular grammar: right or left regular grammar right regular grammar, all rules obey the forms

  1. B ? a where B is a nonterminal in N and a is a terminal in S
  2. B ? aC where B and C are in N and a is in S
  3. B ? e where B is in N and e denotes the empty string, i.e. the string of length 0

left regular grammar, all rules obey the forms

  1. A ? a where A is a nonterminal in N and a is a terminal in S
  2. A ? Ba where A and B are in N and a is in S
  3. A ? e where A is in N and e is the empty string

context free grammar (CFG)

? formal grammar in which every production rule is of the form V ? w

? V is a single nonterminal symbol

? w is a string of terminals and/or nonterminals (w can be empty)

Convert JSON to DataTable

One doesn't always know the type into which to deserialize. So it would be handy to be able to take any JSON (that contains some array) and dynamically produce a table from that.

An issue can arise however, where the deserializer doesn't know where to look for the array to tabulate. When this happens, we get an error message similar to the following:

Unexpected JSON token when reading DataTable. Expected StartArray, got StartObject. Path '', line 1, position 1.

Even if we give it come encouragement or prepare our json accordingly, then "object" types within the array can still prevent tabulation from occurring, where the deserializer doesn't know how to represent the objects in terms of rows, etc. In this case, errors similar to the following occur:

Unexpected JSON token when reading DataTable: StartObject. Path '[0].__metadata', line 3, position 19.

The below example JSON includes both of these problematic features:

      "Enabled": true,
      "Id": 106,
      "Name": "item 1",
      "Enabled": false,
      "Id": 107,
      "Name": "item 2",
      "__metadata": { "Id": 4013 }

So how can we resolve this, and still maintain the flexibility of not knowing the type into which to derialize?

Well here is a simple approach I came up with (assuming you are happy to ignore the object-type properties, such as __metadata in the above example):

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System.Data;
using System.Linq;

public static DataTable Tabulate(string json)
    var jsonLinq = JObject.Parse(json);

    // Find the first array using Linq
    var srcArray = jsonLinq.Descendants().Where(d => d is JArray).First();
    var trgArray = new JArray();
    foreach (JObject row in srcArray.Children<JObject>())
        var cleanRow = new JObject();
        foreach (JProperty column in row.Properties())
            // Only include JValue types
            if (column.Value is JValue)
                cleanRow.Add(column.Name, column.Value);


    return JsonConvert.DeserializeObject<DataTable>(trgArray.ToString());

I know this could be more "LINQy" and has absolutely zero exception handling, but hopefully the concept is conveyed.

We're starting to use more and more services at my work that spit back JSON, so freeing ourselves of strongly-typing everything, is my obvious preference because I'm lazy!

Unable to run Java GUI programs with Ubuntu

Check your X Window environment variables using the "env" command.

How to split a string in two and store it in a field

I would suggest the following:

String[] parsedInput = str.split("\n"); String firstName = parsedInput[0].split(": ")[1]; String lastName = parsedInput[1].split(": ")[1]; myMap.put(firstName,lastName); 

Meaning of .Cells(.Rows.Count,"A").End(xlUp).row

The first part:


Sends you to the bottom row of column A, which you knew already.

The End function starts at a cell and then, depending on the direction you tell it, goes that direction until it reaches the edge of a group of cells that have text. Meaning, if you have text in cells C4:E4 and you type:


The program will select E4, the rightmost cell with text in it.

In your case, the code is spitting out the row of the very last cell with text in it in column A. Does that help?

Eclipse "Server Locations" section disabled and need to change to use Tomcat installation

Right click on the server, then Add/Remove, then remove any projects that are in the Configured panel. Then right click on the server and choose "Clean..." from the context menu. Then the Server Locations option will be enabled.

Option to ignore case with .contains method?

If you are looking for contains & not equals then i would propose below solution. Only drawback is if your searchItem in below solution is "DE" then also it would match

    List<String> list = new ArrayList<>();
    public static final String[] LIST_OF_ELEMENTS = { "ABC", "DEF","GHI" };
    String searchItem= "def";

     if(String.join(",", LIST_OF_ELEMENTS).contains(searchItem.toUpperCase())) {
            System.out.println("found element");

How to give Jenkins more heap space when it´s started as a service under Windows?

I've added to /etc/sysconfig/jenkins (CentOS):

# Options to pass to java when running Jenkins.
JENKINS_JAVA_OPTIONS="-Djava.awt.headless=true -Xmx1024m -XX:MaxPermSize=512m"

For ubuntu the same config should be located in /etc/default

Dynamic LINQ OrderBy on IEnumerable<T> / IQueryable<T>

I guess it would work to use reflection to get whatever property you want to sort on:

IEnumerable<T> myEnumerables
var query=from enumerable in myenumerables
          where some criteria
          orderby GetPropertyValue(enumerable,"SomeProperty")
          select enumerable

private static object GetPropertyValue(object obj, string property)
    System.Reflection.PropertyInfo propertyInfo=obj.GetType().GetProperty(property);
    return propertyInfo.GetValue(obj, null);

Note that using reflection is considerably slower than accessing the property directly, so the performance would have to be investigated.

Change the image source on rollover using jQuery

A generic solution that doesn't limit you to "this image" and "that image" only may be to add the 'onmouseover' and 'onmouseout' tags to the HTML code itself.


<img src="img1.jpg" onmouseover="swap('img2.jpg')" onmouseout="swap('img1.jpg')" />


function swap(newImg){
  this.src = newImg;

Depending on your setup, maybe something like this would work better (and requires less HTML modification).


<img src="img1.jpg" id="ref1" />
<img src="img3.jpg" id="ref2" />
<img src="img5.jpg" id="ref3" />

JavaScript / jQuery

// Declare Arrays
  imgList = new Array();
  imgList["ref1"] = new Array();
  imgList["ref2"] = new Array();
  imgList["ref3"] = new Array();

//Set values for each mouse state
  imgList["ref1"]["out"] = "img1.jpg";
  imgList["ref1"]["over"] = "img2.jpg";
  imgList["ref2"]["out"] = "img3.jpg";
  imgList["ref2"]["over"] = "img4.jpg";
  imgList["ref3"]["out"] = "img5.jpg";
  imgList["ref3"]["over"] = "img6.jpg";

//Add the swapping functions
    $(this).attr("src", imgList[ $(this).attr("id") ]["over"]);

    $(this).attr("src", imgList[ $(this).attr("id") ]["out"]);

How to find difference between two columns data?

select previous, Present, previous-Present as Difference from tablename


select previous, Present, previous-Present as Difference from #TEMP1

Passing parameters in Javascript onClick event

It is probably better to create a dedicated function to create the link so you can avoid creating two anonymous functions. Thus:

<div id="div"></div>

  function getLink(id)
    var link = document.createElement('a');
    link.setAttribute('href', '#');
    link.innerHTML = id;
    link.onclick = function()
    }; = 'block';
    return link;
  var div = document.getElementById('div');
  for (var i = 0; i < 10; i += 1)

Although in both cases you end up with two functions, I just think it is better to wrap it in a function that is semantically easier to comprehend.

How do I check that a number is float or integer?

Any Float number with a zero decimal part (e.g. 1.0, 12.00, 0.0) are implicitly cast to Integer, so it is not possible to check if they are Float or not.

Global Angular CLI version greater than local version

First find out the global angular-cli version by running

ng --version

The above code will show what version is the global and local angular-cli versions.

If you want the global and local angular cli to be same you can just do

npm install --save-dev @angular/[email protected]

where 1.7.4 is your global angular-cli version

Then if you run ng serve --open your code should run.

how to force maven to update local repo

If you are struggling with authenticating to a site, and Maven is caching the results, simply removing the meta-data about the site from the meta-data stash will force Maven to revisit the site.

gvim <local-git-repository>/commons-codec/

how to get the 30 days before date from Todays Date


declare @thirtydaysago datetime
declare @now datetime
set @now = getdate()
set @thirtydaysago = dateadd(day,-30,@now)

select @now, @thirtydaysago

or more simply

select dateadd(day, -30, getdate())




( more DATE_ADD examples on

How to remove first and last character of a string?

Try this to remove the first and last bracket of string ex.[1,2,3]

String s =str.replaceAll("[", "").replaceAll("]", "");

Exptected result = 1,2,3

How do I build JSON dynamically in javascript?

As myJSON is an object you can just set its properties, for example:

myJSON.list1 = ["1","2"];

If you dont know the name of the properties, you have to use the array access syntax:

myJSON['list'+listnum] = ["1","2"];

If you want to add an element to one of the properties, you can do;


R - " missing value where TRUE/FALSE needed "

check the command : NA!=NA : you'll get the result NA, hence the error message.

You have to use the function for your ifstatement to work (in general, it is always better to use this function to check for NA values) :

comments = c("no","yes",NA)
for (l in 1:length(comments)) {
    if (![l])) print(comments[l])
[1] "no"
[1] "yes"

How to debug Javascript with IE 8

I was hoping to add this as a comment to Marcus Westin's reply, but I can't find a link - maybe I need more reputation?

Anyway, thanks, I found this code snippet useful for quick debugging in IE. I have made some quick tweaks to fix a problem that stopped it working for me, also to scroll down automatically and use fixed positioning so it will appear in the viewport. Here's my version in case anyone finds it useful:

myLog = function() {

    var _div = null;

    this.toJson = function(obj) {

        if (typeof window.uneval == 'function') { return uneval(obj); }
        if (typeof obj == 'object') {
            if (!obj) { return 'null'; }
            var list = [];
            if (obj instanceof Array) {
                    for (var i=0;i < obj.length;i++) { list.push(this.toJson(obj[i])); }
                    return '[' + list.join(',') + ']';
            } else {
                    for (var prop in obj) { list.push('"' + prop + '":' + this.toJson(obj[prop])); }
                    return '{' + list.join(',') + '}';
        } else if (typeof obj == 'string') {
            return '"' + obj.replace(/(["'])/g, '\\$1') + '"';
        } else {
            return new String(obj);


    this.createDiv = function() {

        myLog._div = document.body.appendChild(document.createElement('div'));

        var props = {
            position:'fixed', top:'10px', right:'10px', background:'#333', border:'5px solid #333', 
            color: 'white', width: '400px', height: '300px', overflow: 'auto', fontFamily: 'courier new',
            fontSize: '11px', whiteSpace: 'nowrap'

        for (var key in props) {[key] = props[key]; }


    if (!myLog._div) { this.createDiv(); }

    var logEntry = document.createElement('span');

    for (var i=0; i < arguments.length; i++) {
        logEntry.innerHTML += this.toJson(arguments[i]) + '<br />';

    logEntry.innerHTML += '<br />';


    // Scroll automatically to the bottom
    myLog._div.scrollTop = myLog._div.scrollHeight;


How Can I Resolve:"can not open 'git-upload-pack' " error in eclipse?

I also came across this issue trying to push via https to a repo using a self-signed SSL certificate.

The solution for me was running (from the local repository root):

git config http.sslVerify false

How to find list of possible words from a letter matrix [Boggle Solver]

I realize this question's time has come and gone, but since I was working on a solver myself, and stumbled onto this while googling about, I thought I should post a reference to mine as it seems a bit different from some of the others.

I chose to go with a flat array for the game board, and to do recursive hunts from each letter on the board, traversing from valid neighbor to valid neighbor, extending the hunt if the current list of letters if a valid prefix in an index. While traversing the notion of the current word is list of indexes into board, not letters that make up a word. When checking the index, the indexes are translated to letters and the check done.

The index is a brute force dictionary that's a bit like a trie, but allows for Pythonic queries of the index. If the words 'cat' and 'cater' are in the list, you'll get this in the dictionary:

   d = { 'c': ['cat','cater'],
     'ca': ['cat','cater'],
     'cat': ['cat','cater'],
     'cate': ['cater'],
     'cater': ['cater'],

So if the current_word is 'ca' you know that it is a valid prefix because 'ca' in d returns True (so continue the board traversal). And if the current_word is 'cat' then you know that it is a valid word because it is a valid prefix and 'cat' in d['cat'] returns True too.

If felt like this allowed for some readable code that doesn't seem too slow. Like everyone else the expense in this system is reading/building the index. Solving the board is pretty much noise.

The code is at It is intentionally vertical and naive with lots of explicit validity checking because I wanted to understand the problem without crufting it up with a bunch of magic or obscurity.

How To Remove Outline Border From Input Button

button:focus{outline:none !important;}

add !important if it is used in Bootstrap

Font scaling based on width of container

As a JavaScript fallback (or your sole solution), you can use my jQuery Scalem plugin, which lets you scale relative to the parent element (container) by passing the reference option.

How to return a string value from a Bash function

The most straightforward and robust solution is to use command substitution, as other people wrote:

    local x
    echo "$x"

x=$(assign) # This assigns string "Test" to x

The downside is performance as this requires a separate process.

The other technique suggested in this topic, namely passing the name of a variable to assign to as an argument, has side effects, and I wouldn't recommend it in its basic form. The problem is that you will probably need some variables in the function to calculate the return value, and it may happen that the name of the variable intended to store the return value will interfere with one of them:

    local x
    eval "$1=\$x"

assign y # This assigns string "Test" to y, as expected

assign x # This will NOT assign anything to x in this scope
         # because the name "x" is declared as local inside the function

You might, of course, not declare internal variables of the function as local, but you really should always do it as otherwise you may, on the other hand, accidentally overwrite an unrelated variable from the parent scope if there is one with the same name.

One possible workaround is an explicit declaration of the passed variable as global:

    local x
    eval declare -g $1
    eval "$1=\$x"

If name "x" is passed as an argument, the second row of the function body will overwrite the previous local declaration. But the names themselves might still interfere, so if you intend to use the value previously stored in the passed variable prior to write the return value there, be aware that you must copy it into another local variable at the very beginning; otherwise the result will be unpredictable! Besides, this will only work in the most recent version of BASH, namely 4.2. More portable code might utilize explicit conditional constructs with the same effect:

    if [[ $1 != x ]]; then
      local x
    eval "$1=\$x"

Perhaps the most elegant solution is just to reserve one global name for function return values and use it consistently in every function you write.

html5 localStorage error with Safari: "QUOTA_EXCEEDED_ERR: DOM Exception 22: An attempt was made to add something to storage that exceeded the quota."

I just created this repo to provide sessionStorage and localStorage features for unsupported or disabled browsers.

Supported browsers

  • IE5+
  • Chrome all versions
  • Mozilla all versions
  • Yandex all versions

How it works

It detects the feature with the storage type.

function(type) {
    var testKey = '__isSupported',
        storage = window[type];
    try {
        storage.setItem(testKey, '1');
        return true;
    } catch (error) {
        return false;

Sets StorageService.localStorage to window.localStorage if it is supported or creates a cookie storage. Sets StorageService.sessionStorage to window.sessionStorage if it is supported or creates a in memory storage for SPA, cookie storage with sesion features for non SPA.

Show Youtube video source into HTML5 video tag?

The easiest answer is given by W3schools.

  1. Upload your video to Youtube
  2. Note the Video ID
  3. Now write this code in your HTML5.
<iframe width="640" height="520"

Current date and time - Default in MVC razor

If you want to display date time on view without model, just write this:

Date : @DateTime.Now

The output will be:

Date : 16-Aug-17 2:32:10 PM

Get root view from current activity

I tested this in android 4.0.3, only:


give the same view what we get from




giving child of its


Please confirm.

How can I check if a Perl module is installed on my system from the command line?

Bravo for @user80168's solution (I'm still counting \'s !) but to avoid all the escaping involved with aliases and shells:

%~/ cat ~/bin/perlmod
perl -le'eval qq{require $ARGV[0]; } 
    ? print ( "Found $ARGV[0] Version: ", eval "$ARGV[0]->VERSION" ) 
    : print "Not installed" ' $1

works reasonably well.

Here might be the simplest and most "modern" approach, using Module::Runtime:

perl -MModule::Runtime=use_module -E '
     say "$ARGV[0] ", use_module($ARGV[0])->VERSION' DBI

This will give a useful error if the module is not installed.

Using -MModule::Runtime requires it to be installed (it is not a core module).

What is char ** in C?

well, char * means a pointer point to char, it is different from char array.

char amessage[] = "this is an array";  /* define an array*/
char *pmessage = "this is a pointer"; /* define a pointer*/

And, char ** means a pointer point to a char pointer.

You can look some books about details about pointer and array.

POSTing JsonObject With HttpClient From Web API

the code over it in vbnet:

dim FeToSend as new (object--> define class)

Dim client As New HttpClient
Dim content = New StringContent(FeToSend.ToString(), Encoding.UTF8,"application/json")
content.Headers.ContentType = New MediaTypeHeaderValue( "application/json" )
Dim risp = client.PostAsync(Chiamata, content).Result


Hope this help

How do I calculate the MD5 checksum of a file in Python?

In regards to your error and what's missing in your code. m is a name which is not defined for getmd5() function.

No offence, I know you are a beginner, but your code is all over the place. Let's look at your issues one by one :)

First, you are not using hashlib.md5.hexdigest() method correctly. Please refer explanation on hashlib functions in Python Doc Library. The correct way to return MD5 for provided string is to do something like this:

>>> import hashlib
>>> hashlib.md5("filename.exe").hexdigest()

However, you have a bigger problem here. You are calculating MD5 on a file name string, where in reality MD5 is calculated based on file contents. You will need to basically read file contents and pipe it though MD5. My next example is not very efficient, but something like this:

>>> import hashlib
>>> hashlib.md5(open('filename.exe','rb').read()).hexdigest()

As you can clearly see second MD5 hash is totally different from the first one. The reason for that is that we are pushing contents of the file through, not just file name.

A simple solution could be something like that:

# Import hashlib library (md5 method is part of it)
import hashlib

# File to check
file_name = 'filename.exe'

# Correct original md5 goes here
original_md5 = '5d41402abc4b2a76b9719d911017c592'  

# Open,close, read file and calculate MD5 on its contents 
with open(file_name) as file_to_check:
    # read contents of the file
    data =    
    # pipe contents of the file through
    md5_returned = hashlib.md5(data).hexdigest()

# Finally compare original MD5 with freshly calculated
if original_md5 == md5_returned:
    print "MD5 verified."
    print "MD5 verification failed!."

Please look at the post Python: Generating a MD5 checksum of a file. It explains in detail a couple of ways how it can be achieved efficiently.

Best of luck.

JavaScript pattern for multiple constructors

Sometimes, default values for parameters is enough for multiple constructors. And when that doesn't suffice, I try to wrap most of the constructor functionality into an init(other-params) function that is called afterwards. Also consider using the factory concept to make an object that can effectively create the other objects you want.

Passing data through intent using Serializable

I extended ??s???? K's answer to make the code full and workable. So, when you finish filling your 'all_thumbs' list, you should put its content one by one into the bundle and then into the intent:

Bundle bundle = new Bundle();

for (int i = 0; i<all_thumbs.size(); i++)
bundle.putSerializable("extras"+i, all_thumbs.get(i));


In order to get the extras from the intent, you need:

Bundle bundle = new Bundle();
List<Thumbnail> thumbnailObjects = new ArrayList<Thumbnail>();

// collect your Thumbnail objects
for (String key : bundle.keySet()) {
thumbnailObjects.add((Thumbnail) bundle.getSerializable(key));

// for example, in order to get a value of the 3-rd object you need to:
String label = thumbnailObjects.get(2).get_label();

Advantage of Serializable is its simplicity. However, I would recommend you to consider using Parcelable method when you need transfer many data, because Parcelable is specifically designed for Android and it is more efficient than Serializable. You can create Parcelable class using:

  1. an online tool - parcelabler
  2. a plugin for Android Studion - Android Parcelable code generator

Bind event to right mouse click

There is no built-in oncontextmenu event handler in jQuery, but you can do something like this:

  document.oncontextmenu = function() {return false;};

    if( e.button == 2 ) { 
      alert('Right mouse button!'); 
      return false; 
    return true; 

Basically I cancel the oncontextmenu event of the DOM element to disable the browser context menu, and then I capture the mousedown event with jQuery, and there you can know in the event argument which button has been pressed.

You can try the above example here.

How to find the .NET framework version of a Visual Studio project?

It depends which version of Visual Studio:

  • In 2002, all projects use .Net 1.0
  • In 2003, all projects use .Net 1.1
  • In 2005, all projects use .Net 2.0
  • In 2008, projects use .Net 2.0, 3.0, or 3.5; you can change the version in Project Properties
  • In 2010, projects use .Net 2.0, 3.0, 3.5, or 4.0; you can change the version in Project Properties
  • In 2012, projects use .Net 2.0, 3.0, 3.5, 4.0 or 4.5; you can change the version in Project Properties

Newer versions of Visual Studio support many versions of the .Net framework; check your project type and properties.

Mongoose's find method with $or condition does not work properly

I implore everyone to use Mongoose's query builder language and promises instead of callbacks:

User.find().or([{ name: param }, { nickname: param }])
    .then(users => { /*logic here*/ })
    .catch(error => { /*error logic here*/ })

Read more about Mongoose Queries.

The requested URL /about was not found on this server

There is a trusted answer on the Wordpress website:

Where's my .htaccess file?

WordPress's index.php and .htaccess files should be together in the directory indicated by the Site address (URL) setting on your General Options page. Since the name of the file begins with a dot, the file may not be visible through an FTP client unless you change the preferences of the FTP tool to show all files, including the hidden files. Some hosts (e.g. Godaddy) may not show or allow you to edit .htaccess if you install WordPress through the Godaddy Hosting Connection installation.

Creating and editing (.htaccess)

If you do not already have a .htaccess file, create one. If you have shell or ssh access to the server, a simple touch .htaccess command will create the file. If you are using FTP to transfer files, create a file on your local computer, call it 1.htaccess, upload it to the root of your WordPress folder, and then rename it to .htaccess.

You can edit the .htaccess file by FTP, shell, or (possibly) your host's control panel.

The following permalink rewrite code should be included in your .htaccess file (since WordPress 3.0):

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
# END WordPress

*Taken from here.

align textbox and text/labels in html?

you can do a multi div layout like this

<div class="fieldcontainer">
    <div class="label"></div>
    <div class="field"></div>

where .fieldcontainer { clear: both; } .label { float: left; width: ___ } .field { float: left; }

Or, I actually prefer tables for forms like this. This is very much tabular data and it comes out very clean. Both will work though.

'invalid value encountered in double_scalars' warning, possibly numpy

Zero-size array passed to numpy.mean raises this warning (as indicated in several comments).

For some other candidates:

  • median also raises this warning on zero-sized array.

other candidates do not raise this warning:

  • min,argmin both raise ValueError on empty array
  • randn takes *arg; using randn(*[]) returns a single random number
  • std,var return nan on an empty array

How to send a JSON object over Request with Android?

HttpPost is deprecated by Android Api Level 22. So, Use HttpUrlConnection for further.

public static String makeRequest(String uri, String json) {
    HttpURLConnection urlConnection;
    String url;
    String data = json;
    String result = null;
    try {
        urlConnection = (HttpURLConnection) ((new URL(uri).openConnection()));
        urlConnection.setRequestProperty("Content-Type", "application/json");
        urlConnection.setRequestProperty("Accept", "application/json");

        OutputStream outputStream = urlConnection.getOutputStream();
        BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));

        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream(), "UTF-8"));

        String line = null;
        StringBuilder sb = new StringBuilder();

        while ((line = bufferedReader.readLine()) != null) {

        result = sb.toString();

    } catch (UnsupportedEncodingException e) {
    } catch (IOException e) {
    return result;

Avoid dropdown menu close on click inside

This should help as well

$(document).on('click', 'someyourContainer .dropdown-menu', function (e) {

Bootstrap modal in React.js

You can use React-Bootstrap ( There is an example for modals at that link. Once you have loaded react-bootstrap, the modal component can be used as a react component:

var Modal = ReactBootstrap.Modal;

can then be used as a react component as <Modal/>.

For Bootstrap 4, there is react-strap ( React-Bootstrap only supports Bootstrap 3.

Print time in a batch file (milliseconds)

To time task in CMD is as simple as

echo %TIME% && your_command && cmd /v:on /c echo !TIME!

Windows 7 environment variable not working in path

%M2% and %JAVA_HOME% need to be added to a PATH variable in the USER variables, not the SYSTEM variables.

How do I autoindent in Netbeans?

I have netbeans 6.9.1 open right now and ALT+SHIFT+F indents only the lines you have selected.

If no lines are selected then it will indent the whole document you are in.

1 possibly unintended behavior is that if you have selected ONLY 1 line, it must be selected completely, otherwise it does nothing. But you don't have to completely select the last line of a group nor the first.

I expected it to indent only one line by just selecting the first couple of chars but didn't work, yea i know i am lazy as hell...

PHPDoc type hinting for array of objects?

I've found something which is working, it can save lives !

private $userList = array();
$userList = User::fetchAll(); // now $userList is an array of User objects
foreach ($userList as $user) {
   $user instanceof User;
   echo $user->getName();

Change Timezone in Lumen or Laravel 5

Go to config -> app.php and change 'timezone' => 'Asia/Jakarta',

(this is my timezone)

Best PHP IDE for Mac? (Preferably free!)

PDT eclipse from ZEND has a mac version (PDT all-in-one).

I've been using it for about 3 months and it's pretty solid and has debugging capabilities with xdebug (debug howto) and zend debugger.

How to "fadeOut" & "remove" a div in jQuery?

.fadeOut('slow', this.remove);

how to access parent window object using jquery?

Here is a more literal answer (parent window as opposed to opener) to the original question that can be used within an iframe, assuming the domain name in the iframe matches that of the parent window:


MySQL & Java - Get id of the last inserted value (JDBC)

Wouldn't you just change:

numero = stmt.executeUpdate(query);


numero = stmt.executeUpdate(query, Statement.RETURN_GENERATED_KEYS);

Take a look at the documentation for the JDBC Statement interface.

Update: Apparently there is a lot of confusion about this answer, but my guess is that the people that are confused are not reading it in the context of the question that was asked. If you take the code that the OP provided in his question and replace the single line (line 6) that I am suggesting, everything will work. The numero variable is completely irrelevant and its value is never read after it is set.

How to get current user in core

This is old question but my case shows that my case wasn't discussed here.

I like the most the answer of Simon_Weaver ( He explains in details how to get user name using IPrincipal and IIdentity. This answer is absolutely correct and I recommend to use this approach. However, during debugging I encountered with the problem when ASP.NET can NOT populate service principle properly. (or in other words, IPrincipal.Identity.Name is null)

It's obvious that to get user name MVC framework should take it from somewhere. In the .NET world, ASP.NET or ASP.NET Core is using Open ID Connect middleware. In the simple scenario web apps authenticate a user in a web browser. In this scenario, the web application directs the user’s browser to sign them in to Azure AD. Azure AD returns a sign-in response through the user’s browser, which contains claims about the user in a security token. To make it work in the code for your application, you'll need to provide the authority to which you web app delegates sign-in. When you deploy your web app to Azure Service the common scenario to meet this requirements is to configure web app: "App Services" -> YourApp -> "Authentication / Authorization" blade -> "App Service Authenticatio" = "On" and so on ( I beliebe (this is my educated guess) that under the hood of this process the wizard adjusts "parent" web config of this web app by adding the same settings that I show in following paragraphs. Basically, the issue why this approach does NOT work in ASP.NET Core is because "parent" machine config is ignored by webconfig. (this is not 100% sure, I just give the best explanation that I have). So, to meke it work you need to setup this manually in your app.

Here is an article that explains how to manyally setup your app to use Azure AD.

Step 1: Register the sample with your Azure AD tenant. (it's obvious, don't want to spend my time of explanations).

Step 2: In the appsettings.json file: replace the ClientID value with the Application ID from the application you registered in Application Registration portal on Step 1. replace the TenantId value with common

Step 3: Open the Startup.cs file and in the ConfigureServices method, after the line containing .AddAzureAD insert the following code, which enables your application to sign in users with the Azure AD v2.0 endpoint, that is both Work and School and Microsoft Personal accounts.

services.Configure<OpenIdConnectOptions>(AzureADDefaults.OpenIdScheme, options =>
    options.Authority = options.Authority + "/v2.0/";
    options.TokenValidationParameters.ValidateIssuer = false;

Summary: I've showed one more possible issue that could leed to an error that topic starter is explained. The reason of this issue is missing configurations for Azure AD (Open ID middleware). In order to solve this issue I propose manually setup "Authentication / Authorization". The short overview of how to setup this is added.

getaddrinfo: nodename nor servname provided, or not known

I restarted my computer (Mac Mountain Lion) and the problem fixed itself. Something having to do with the shell thinking it was disconnected from the internet I think.

Restarting your shell in some definite way may solve this problem as well. Simply opening up a new session/window however did not work.

Default visibility for C# classes and members (fields, methods, etc.)?

All of the information you are looking for can be found here and here (thanks Reed Copsey):

From the first link:

Classes and structs that are declared directly within a namespace (in other words, that are not nested within other classes or structs) can be either public or internal. Internal is the default if no access modifier is specified.


The access level for class members and struct members, including nested classes and structs, is private by default.


interfaces default to internal access.


Delegates behave like classes and structs. By default, they have internal access when declared directly within a namespace, and private access when nested.

From the second link:

Top-level types, which are not nested in other types, can only have internal or public accessibility. The default accessibility for these types is internal.

And for nested types:

Members of    Default member accessibility
----------    ----------------------------
enum          public
class         private
interface     public
struct        private

What is a void pointer in C++?

A void* does not mean anything. It is a pointer, but the type that it points to is not known.

It's not that it can return "anything". A function that returns a void* generally is doing one of the following:

  • It is dealing in unformatted memory. This is what operator new and malloc return: a pointer to a block of memory of a certain size. Since the memory does not have a type (because it does not have a properly constructed object in it yet), it is typeless. IE: void.
  • It is an opaque handle; it references a created object without naming a specific type. Code that does this is generally poorly formed, since this is better done by forward declaring a struct/class and simply not providing a public definition for it. Because then, at least it has a real type.
  • It returns a pointer to storage that contains an object of a known type. However, that API is used to deal with objects of a wide variety of types, so the exact type that a particular call returns cannot be known at compile time. Therefore, there will be some documentation explaining when it stores which kinds of objects, and therefore which type you can safely cast it to.

This construct is nothing like dynamic or object in C#. Those tools actually know what the original type is; void* does not. This makes it far more dangerous than any of those, because it is very easy to get it wrong, and there's no way to ask if a particular usage is the right one.

And on a personal note, if you see code that uses void*'s "often", you should rethink what code you're looking at. void* usage, especially in C++, should be rare, used primary for dealing in raw memory.

Jquery post, response in new window

Use the write()-Method of the Popup's document to put your markup there:

$.post(url, function (data) {
    var w ='about:blank');;

What is compiler, linker, loader?

A compiler is a special program that processes statements written in a particular programming language and turns them into machine language or "code" that a computer's processor uses

Kubernetes how to make Deployment to update image

kubectl rollout restart deployment myapp

This is the current way to trigger a rolling update and leave the old replica sets in place for other operations provided by kubectl rollout like rollbacks.

Python String and Integer concatenation

If we want output like 'string0123456789' then we can use map function and join method of string.

>>> 'string'+"".join(map(str,xrange(10)))

If we want List of string values then use list comprehension method.

>>> ['string'+i for i in map(str,xrange(10))]
['string0', 'string1', 'string2', 'string3', 'string4', 'string5', 'string6', 'string7', 'string8', 'string9']


Use xrange() for Python 2.x

USe range() for Python 3.x

Pandas create empty DataFrame with only column names

Are you looking for something like this?

    df = pd.DataFrame(columns=COLUMN_NAMES)

   Index(['A', 'B', 'C', 'D', 'E', 'F', 'G'], dtype='object')

How to manually set an authenticated user in Spring Security / SpringMVC

The new filtering feature in Servlet 2.4 basically alleviates the restriction that filters can only operate in the request flow before and after the actual request processing by the application server. Instead, Servlet 2.4 filters can now interact with the request dispatcher at every dispatch point. This means that when a Web resource forwards a request to another resource (for instance, a servlet forwarding the request to a JSP page in the same application), a filter can be operating before the request is handled by the targeted resource. It also means that should a Web resource include the output or function from other Web resources (for instance, a JSP page including the output from multiple other JSP pages), Servlet 2.4 filters can work before and after each of the included resources. .

To turn on that feature you need:




return "forward:/login?j_username=" + registrationModel.getUserEmail()
        + "&j_password=" + registrationModel.getPassword();

Git fetch remote branch

Check your .git/config file, particularly what tracking is present on fetch for that remote.

[remote "randomRemote"]
    url = [email protected]:someUser/someRepo.git
    fetch = +refs/heads/*:refs/remotes/randomRemote/*

If it has heads/* pointing to randomRemote/*, when you run git fetch randomRemote, it will fetch all branches.

Then you can just checkout that branch.


  1. You need to add remote branches to the tracking using this. Check your .git/config after running this. You will understand.

    git remote set-branches --add randomRemote randomBranch
  2. Run git fetch randomRemote. This will fetch the remote branch.

  3. Now you can run git checkout randomBranch.

How do you clear your Visual Studio cache on Windows Vista?

The accepted answer gave two locations:


C:\Documents and Settings\Administrator\Local Settings\Temp\VWDWebCache

and possibly here

C:\Documents and Settings\Administrator\Local Settings\Application Data\Microsoft\WebsiteCache

Did you try those?

Edited to add

On my Windows Vista machine, it's located in


and in


From your additional information (regarding team edition) this comes from Clear Client TFS Cache:

Clear Client TFS Cache

Visual Studio and Team Explorer provide a caching mechanism which can get out of sync. If I have multiple instances of a single TFS which can be connected to from a single Visual Studio client, that client can become confused.

To solve it..

For Windows Vista delete contents of this folder

%LocalAppData%\Microsoft\Team Foundation\1.0\Cache

Why doesn't TFS get latest get the latest?

Every time this happens to me (so far) is because I have local edits pending on the .csproj project file. That file seems to keep a list of all the files included in the project. Any new files added by somebody else are "not downloaded" because they are not in my locally edited (now stale) project file. To get all the files I first have to undo pending changes to the .csproj file first then "get all". I do not have to undo other changes I have made, but I may have to go back and include my new files again (and then the next guy gets the same problem when he tries to "get all"...)

It seems to me there is some fundamental kludginess when multiple people are adding new files at the same time.

(this is in .Net Framework projects, maybe the other frameworks like Core behave differently)

System.IO.FileNotFoundException: Could not load file or assembly 'X' or one of its dependencies when deploying the application

I resolved this problem by renaming the DLL. The DLL had been manually renamed when it was uploaded to its shared location (a version number was appended to the file name). Removing the version number from the downloaded file resolved the issue.

How can I add new keys to a dictionary?

I think it would also be useful to point out Python's collections module that consists of many useful dictionary subclasses and wrappers that simplify the addition and modification of data types in a dictionary, specifically defaultdict:

dict subclass that calls a factory function to supply missing values

This is particularly useful if you are working with dictionaries that always consist of the same data types or structures, for example a dictionary of lists.

>>> from collections import defaultdict
>>> example = defaultdict(int)
>>> example['key'] += 1
>>> example['key']
defaultdict(<class 'int'>, {'key': 1})

If the key does not yet exist, defaultdict assigns the value given (in our case 10) as the initial value to the dictionary (often used inside loops). This operation therefore does two things: it adds a new key to a dictionary (as per question), and assigns the value if the key doesn't yet exist. With the standard dictionary, this would have raised an error as the += operation is trying to access a value that doesn't yet exist:

>>> example = dict()
>>> example['key'] += 1
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
KeyError: 'key'

Without the use of defaultdict, the amount of code to add a new element would be much greater and perhaps looks something like:

# This type of code would often be inside a loop
if 'key' not in example:
    example['key'] = 0  # add key and initial value to dict; could also be a list
example['key'] += 1  # this is implementing a counter

defaultdict can also be used with complex data types such as list and set:

>>> example = defaultdict(list)
>>> example['key'].append(1)
>>> example
defaultdict(<class 'list'>, {'key': [1]})

Adding an element automatically initialises the list.

C# using streams

Streams are good for dealing with large amounts of data. When it's impractical to load all the data into memory at the same time, you can open it as a stream and work with small chunks of it.

What is the easiest way to encrypt a password when I save it to the registry?

One option would be to store the hash (SHA1, MD5) of the password instead of the clear-text password, and whenever you want to see if the password is good, just compare it to that hash.

If you need secure storage (for example for a password that you will use to connect to a service), then the problem is more complicated.

If it is just for authentication, then it would be enough to use the hash.

Gmail: 530 5.5.1 Authentication Required. Learn more at

You need to go here

then select Gmail and then select device. then click on Generate. Simply Copy & Paste password which is generated by Google.

How to sort with lambda in Python

You're trying to use key functions with lambda functions.

Python and other languages like C# or F# use lambda functions.

Also, when it comes to key functions and according to the documentation

Both list.sort() and sorted() have a key parameter to specify a function to be called on each list element prior to making comparisons.


The value of the key parameter should be a function that takes a single argument and returns a key to use for sorting purposes. This technique is fast because the key function is called exactly once for each input record.

So, key functions have a parameter key and it can indeed receive a lambda function.

In Real Python there's a nice example of its usage. Let's say you have the following list

ids = ['id1', 'id100', 'id2', 'id22', 'id3', 'id30']

and want to sort through its "integers". Then, you'd do something like

sorted_ids = sorted(ids, key=lambda x: int(x[2:])) # Integer sort

and printing it would give

['id1', 'id2', 'id3', 'id22', 'id30', 'id100']

In your particular case, you're only missing to write key= before lambda. So, you'd want to use the following

a = sorted(a, key=lambda x: x.modified, reverse=True)

Accessing a class' member variables in Python?

If you have an instance function (i.e. one that gets passed self) you can use self to get a reference to the class using self.__class__

For example in the code below tornado creates an instance to handle get requests, but we can get hold of the get_handler class and use it to hold a riak client so we do not need to create one for every request.

import tornado.web
import riak

class get_handler(tornado.web.requestHandler):
    riak_client = None

    def post(self):
        cls = self.__class__
        if cls.riak_client is None:
            cls.riak_client = riak.RiakClient(pb_port=8087, protocol='pbc')
        # Additional code to send response to the request ...

How to change position of Toast in Android?

setting toast at topin screen

toast.setGravity(Gravity.BOTTOM , 0, 0); // here i am setting toast at bottom

now at bottom

 toast.setGravity(Gravity.BOTTOM , 0, 0); // here i am setting toast at bottom

the same way we can set toast in left, right and also center

Click here

How can I force clients to refresh JavaScript files?

Athough it is framework specific, Django 1.4 has this functionailty which works in a similar fashion to the link to the 'greenfelt' site in the above answer

XSS prevention in JSP/Servlet web application

If you want to make sure that your $ operator does not suffer from XSS hack you can implement ServletContextListener and do some checks there.

The complete solution at:

public class EscapeXmlELResolverListener implements ServletContextListener {
    private static final Logger LOG = LoggerFactory.getLogger(EscapeXmlELResolverListener.class);

    public void contextInitialized(ServletContextEvent event) {"EscapeXmlELResolverListener initialized ...");        
                .addELResolver(new EscapeXmlELResolver());


    public void contextDestroyed(ServletContextEvent event) {"EscapeXmlELResolverListener destroyed");

     * {@link ELResolver} which escapes XML in String values.
    public class EscapeXmlELResolver extends ELResolver {

        private ThreadLocal<Boolean> excludeMe = new ThreadLocal<Boolean>() {
            protected Boolean initialValue() {
                return Boolean.FALSE;

        public Object getValue(ELContext context, Object base, Object property) {

            try {
                    if (excludeMe.get()) {
                        return null;

                    // This resolver is in the original resolver chain. To prevent
                    // infinite recursion, set a flag to prevent this resolver from
                    // invoking the original resolver chain again when its turn in the
                    // chain comes around.
                    Object value = context.getELResolver().getValue(
                            context, base, property);

                    if (value instanceof String) {
                        value = StringEscapeUtils.escapeHtml4((String) value);
                    return value;
            } finally {

        public Class<?> getCommonPropertyType(ELContext context, Object base) {
            return null;

        public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext context, Object base){
            return null;

        public Class<?> getType(ELContext context, Object base, Object property) {
            return null;

        public boolean isReadOnly(ELContext context, Object base, Object property) {
            return true;

        public void setValue(ELContext context, Object base, Object property, Object value){
            throw new UnsupportedOperationException();



Again: This only guards the $. Please also see other answers.

How to use EOF to run through a text file in C?

How you detect EOF depends on what you're using to read the stream:

function                  result on EOF or error                    
--------                  ----------------------
fgets()                   NULL
fscanf()                  number of succesful conversions
                            less than expected
fgetc()                   EOF
fread()                   number of elements read
                            less than expected

Check the result of the input call for the appropriate condition above, then call feof() to determine if the result was due to hitting EOF or some other error.

Using fgets():

 char buffer[BUFFER_SIZE];
 while (fgets(buffer, sizeof buffer, stream) != NULL)
   // process buffer
 if (feof(stream))
   // hit end of file
   // some other error interrupted the read

Using fscanf():

char buffer[BUFFER_SIZE];
while (fscanf(stream, "%s", buffer) == 1) // expect 1 successful conversion
  // process buffer
if (feof(stream)) 
  // hit end of file
  // some other error interrupted the read

Using fgetc():

int c;
while ((c = fgetc(stream)) != EOF)
  // process c
if (feof(stream))
  // hit end of file
  // some other error interrupted the read

Using fread():

char buffer[BUFFER_SIZE];
while (fread(buffer, sizeof buffer, 1, stream) == 1) // expecting 1 
                                                     // element of size
                                                     // BUFFER_SIZE
   // process buffer
if (feof(stream))
  // hit end of file
  // some other error interrupted read

Note that the form is the same for all of them: check the result of the read operation; if it failed, then check for EOF. You'll see a lot of examples like:

  fscanf(stream, "%s", buffer);

This form doesn't work the way people think it does, because feof() won't return true until after you've attempted to read past the end of the file. As a result, the loop executes one time too many, which may or may not cause you some grief.

Git, fatal: The remote end hung up unexpectedly

Culprit (in my case):
A high-latency network.

This is not an answer per se but more of an observation that may help others. I found that this error pops up occasionally on high-latency networks (I have to use a Satellite dish for internet access for example). The speed of the network is fine, but the latency can be high. Note: The problem only exists in certain scenarios, but I have not determined what the pattern is.

Temporary mitigation:
I switched networks—I moved to a slower, but lower latency cell network (my phone used as a hotspot)—and the problem disappeared. Note that I can only do this itermittently because my cell connectivity is also intermittent. Plus the bandwidth usage adds costs. I'm also lucky that I have this option available to me. Not everyone does.

I'm sure there is some configuration setting somewhere that makes git—or ssh or curl or whatever times out first—more tolerant of such networks, but I don't know what it is.

A plea to developers:
These kinds of issues are a constant problem for rural populations. Please think of us when you design your systems, tools, and applications. Thank you.

How to really read text file from classpath in Java

you have to put your 'system variable' on the java classpath.

Oracle SQL: Use sequence in insert with Select Statement

Assuming that you want to group the data before you generate the key with the sequence, it sounds like you want something like

SELECT MY_SEQ.nextval,
  FROM (SELECT '2010' year,
               '12' month,
               'ALL' make,
               'ALL' model,
               sum(AVG_MSRP*COUNT)/sum(COUNT) avg_msrp,
               sum(cnt) cnt
         WHERE YEAR = '2010' 
           AND MONTH = '12'
           AND MAKE != 'ALL' 

Access Controller method from another controller in Laravel 5

Here the trait fully emulates running controller by laravel router (including support of middlewares and dependency injection). Tested only with 5.4 version


namespace App\Traits;

use Illuminate\Pipeline\Pipeline;
use Illuminate\Routing\ControllerDispatcher;
use Illuminate\Routing\MiddlewareNameResolver;
use Illuminate\Routing\SortedMiddleware;

trait RunsAnotherController
    public function runController($controller, $method = 'index')
        $middleware = $this->gatherControllerMiddleware($controller, $method);

        $middleware = $this->sortMiddleware($middleware);

        return $response = (new Pipeline(app()))
            ->then(function ($request) use ($controller, $method) {
                return app('router')->prepareResponse(
                    $request, (new ControllerDispatcher(app()))->dispatch(
                    app('router')->current(), $controller, $method

    protected function gatherControllerMiddleware($controller, $method)
        return collect($this->controllerMidlleware($controller, $method))->map(function ($name) {
            return (array)MiddlewareNameResolver::resolve($name, app('router')->getMiddleware(), app('router')->getMiddlewareGroups());

    protected function controllerMidlleware($controller, $method)
        return ControllerDispatcher::getMiddleware(
            $controller, $method

    protected function sortMiddleware($middleware)
        return (new SortedMiddleware(app('router')->middlewarePriority, $middleware))->all();

Then just add it to your class and run the controller. Note, that dependency injection will be assigned with your current route.

class CustomController extends Controller {
    use RunsAnotherController;

    public function someAction() 
        $controller = app()->make('App\Http\Controllers\AnotherController');

        return $this->runController($controller, 'doSomething');

How to Verify if file exist with VB script

There is no built-in functionality in VBS for that, however, you can use the FileSystemObject FileExists function for that :

Option Explicit
DIM fso    
Set fso = CreateObject("Scripting.FileSystemObject")

If (fso.FileExists("C:\Program Files\conf")) Then
  WScript.Echo("File exists!")
  WScript.Echo("File does not exist!")
End If


How do I replace whitespaces with underscore?

OP is using python, but in javascript (something to be careful of since the syntaxes are similar.

// only replaces the first instance of ' ' with '_'
"one two three".replace(' ', '_'); 
=> "one_two three"

// replaces all instances of ' ' with '_'
"one two three".replace(/\s/g, '_');
=> "one_two_three"

How can I view an old version of a file with Git?

You can use a script like this to dump all the versions of a file to separate files:

e.g. path/to/somefile.txt

Get the script here as an answer to another similar question

MVVM Passing EventArgs As Command Parameter

Prism's InvokeCommandAction will pass the event args by default if CommandParameter is not set.

Here is an example. Note the use of prism:InvokeCommandAction instead of i:InvokeCommandAction.

    <i:EventTrigger EventName="Sorting">
        <prism:InvokeCommandAction Command="{Binding SortingCommand}"/>

The ViewModel

    private DelegateCommand<EventArgs> _sortingCommand;

    public DelegateCommand<EventArgs> SortingCommand => _sortingCommand ?? (_sortingCommand = new DelegateCommand<EventArgs>(OnSortingCommand));

    private void OnSortingCommand(EventArgs obj)
        //do stuff

There is a new version of the Prismlibrary documentation.

MySQL Error: #1142 - SELECT command denied to user

This is th privileges issue in your database users. first check and grant permission to user 'marco' in localhost

Why use static_cast<int>(x) instead of (int)x?

C Style casts are easy to miss in a block of code. C++ style casts are not only better practice; they offer a much greater degree of flexibility.

reinterpret_cast allows integral to pointer type conversions, however can be unsafe if misused.

static_cast offers good conversion for numeric types e.g. from as enums to ints or ints to floats or any data types you are confident of type. It does not perform any run time checks.

dynamic_cast on the other hand will perform these checks flagging any ambiguous assignments or conversions. It only works on pointers and references and incurs an overhead.

There are a couple of others but these are the main ones you will come across.

In log4j, does checking isDebugEnabled before logging improve performance?

Since many people are probably viewing this answer when searching for log4j2 and nearly all current answers do not consider log4j2 or recent changes in it, this should hopefully answer the question.

log4j2 supports Suppliers (currently their own implementation, but according to the documentation it is planned to use Java's Supplier interface in version 3.0). You can read a little bit more about this in the manual. This allows you to put expensive log message creation into a supplier which only creates the message if it is going to be logged:

LogManager.getLogger().debug(() -> createExpensiveLogMessage());

How to Convert Excel Numeric Cell Value into Words

There is no built-in formula in excel, you have to add a vb script and permanently save it with your MS. Excel's installation as Add-In.

  1. press Alt+F11
  2. MENU: (Tool Strip) Insert Module
  3. copy and paste the below code

Option Explicit

Public Numbers As Variant, Tens As Variant

Sub SetNums()
    Numbers = Array("", "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine", "Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen", "Nineteen")
    Tens = Array("", "", "Twenty", "Thirty", "Forty", "Fifty", "Sixty", "Seventy", "Eighty", "Ninety")
End Sub

Function WordNum(MyNumber As Double) As String
    Dim DecimalPosition As Integer, ValNo As Variant, StrNo As String
    Dim NumStr As String, n As Integer, Temp1 As String, Temp2 As String
    ' This macro was written by Chris Mead -
    If Abs(MyNumber) > 999999999 Then
        WordNum = "Value too large"
        Exit Function
    End If
    ' String representation of amount (excl decimals)
    NumStr = Right("000000000" & Trim(Str(Int(Abs(MyNumber)))), 9)
    ValNo = Array(0, Val(Mid(NumStr, 1, 3)), Val(Mid(NumStr, 4, 3)), Val(Mid(NumStr, 7, 3)))
    For n = 3 To 1 Step -1    'analyse the absolute number as 3 sets of 3 digits
        StrNo = Format(ValNo(n), "000")
        If ValNo(n) > 0 Then
            Temp1 = GetTens(Val(Right(StrNo, 2)))
            If Left(StrNo, 1) <> "0" Then
                Temp2 = Numbers(Val(Left(StrNo, 1))) & " hundred"
                If Temp1 <> "" Then Temp2 = Temp2 & " and "
                Temp2 = ""
            End If
            If n = 3 Then
                If Temp2 = "" And ValNo(1) + ValNo(2) > 0 Then Temp2 = "and "
                WordNum = Trim(Temp2 & Temp1)
            End If
            If n = 2 Then WordNum = Trim(Temp2 & Temp1 & " thousand " & WordNum)
            If n = 1 Then WordNum = Trim(Temp2 & Temp1 & " million " & WordNum)
        End If
    Next n
    NumStr = Trim(Str(Abs(MyNumber)))
    ' Values after the decimal place
    DecimalPosition = InStr(NumStr, ".")
    Numbers(0) = "Zero"
    If DecimalPosition > 0 And DecimalPosition < Len(NumStr) Then
        Temp1 = " point"
        For n = DecimalPosition + 1 To Len(NumStr)
            Temp1 = Temp1 & " " & Numbers(Val(Mid(NumStr, n, 1)))
        Next n
        WordNum = WordNum & Temp1
    End If
    If Len(WordNum) = 0 Or Left(WordNum, 2) = " p" Then
        WordNum = "Zero" & WordNum
    End If
End Function

Function GetTens(TensNum As Integer) As String
' Converts a number from 0 to 99 into text.
    If TensNum <= 19 Then
        GetTens = Numbers(TensNum)
        Dim MyNo As String
        MyNo = Format(TensNum, "00")
        GetTens = Tens(Val(Left(MyNo, 1))) & " " & Numbers(Val(Right(MyNo, 1)))
    End If
End Function

After this, From File Menu select Save Book ,from next menu select "Excel 97-2003 Add-In (*.xla)

It will save as Excel Add-In. that will be available till the Ms.Office Installation to that machine.

Now Open any Excel File in any Cell type =WordNum(<your numeric value or cell reference>)

you will see a Words equivalent of the numeric value.

This Snippet of code is taken from:

Remove blue border from css custom-styled button in Chrome

I faced the same issue so I used simple CSS-

.custom-button {
    outline: none

FormData.append("key", "value") is not working

New in Chrome 50+ and Firefox 39+ (resp. 44+):

  • formdata.entries() (combine with Array.from() for debugability)
  • formdata.get(key)
  • and more very useful methods

Original answer:

What I usually do to 'debug' a FormData object, is just send it (anywhere!) and check the browser logs (eg. Chrome devtools' Network tab).

You don't need a/the same Ajax framework. You don't need any details. Just send it:

var xhr = new XMLHttpRequest;'POST', '/', true);


HTML table with fixed headers and a fixed column?

You might be looking for this.

It has some known issues though.

Pure CSS collapse/expand div

@gbtimmon's answer is great, but way, way too complicated. I've simplified his code as much as I could.

#hide:target {
    display: none; 

#hide:target + #show,
#hide:target ~ #answer {
    display: inherit; 
<a href="#hide" id="hide">Show</a>
<a href="#/" id="show">Hide</a>
<div id="answer"><p>Answer</p></div>

Browser can't access/find relative resources like CSS, images and links when calling a Servlet which forwards to a JSP

You can try out this one as well as. Because this worked for me and it's simple.

    <%@ include file="/css/style.css" %>

Force drop mysql bypassing foreign key constraint

Simple solution to drop all the table at once from terminal.

This involved few steps inside your mysql shell (not a one step solution though), this worked me and saved my day.

Worked for Server version: 5.6.38 MySQL Community Server (GPL)

Steps I followed:

 1. generate drop query using concat and group_concat.
 2. use database
 3. turn off / disable foreign key constraint check (SET FOREIGN_KEY_CHECKS = 0;), 
 4. copy the query generated from step 1
 5. re enable foreign key constraint check (SET FOREIGN_KEY_CHECKS = 1;)
 6. run show table

MySQL shell

$ mysql -u root -p
Enter password: ****** (your mysql root password)
mysql> SELECT CONCAT('DROP TABLE IF EXISTS `', GROUP_CONCAT(table_name SEPARATOR '`, `'), '`;') AS dropquery FROM information_schema.tables WHERE table_schema = 'emall_duplicate';
| dropquery                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| DROP TABLE IF EXISTS `admin`, `app`, `app_meta_settings`, `commission`, `commission_history`, `coupon`, `email_templates`, `infopages`, `invoice`, `m_pc_xref`, `member`, `merchant`, `message_templates`, `mnotification`, `mshipping_address`, `notification`, `order`, `orderdetail`, `pattributes`, `pbrand`, `pcategory`, `permissions`, `pfeatures`, `pimage`, `preport`, `product`, `product_review`, `pspecification`, `ptechnical_specification`, `pwishlist`, `role_perms`, `roles`, `settings`, `test`, `testanother`, `user_perms`, `user_roles`, `users`, `wishlist`; |
1 row in set (0.00 sec)

mysql> USE emall_duplicate;
Database changed
mysql> SET FOREIGN_KEY_CHECKS = 0;                                                                                                                                                   Query OK, 0 rows affected (0.00 sec)

// copy and paste generated query from step 1
mysql> DROP TABLE IF EXISTS `admin`, `app`, `app_meta_settings`, `commission`, `commission_history`, `coupon`, `email_templates`, `infopages`, `invoice`, `m_pc_xref`, `member`, `merchant`, `message_templates`, `mnotification`, `mshipping_address`, `notification`, `order`, `orderdetail`, `pattributes`, `pbrand`, `pcategory`, `permissions`, `pfeatures`, `pimage`, `preport`, `product`, `product_review`, `pspecification`, `ptechnical_specification`, `pwishlist`, `role_perms`, `roles`, `settings`, `test`, `testanother`, `user_perms`, `user_roles`, `users`, `wishlist`;
Query OK, 0 rows affected (0.18 sec)

Query OK, 0 rows affected (0.00 sec)

mysql> SHOW tables;
Empty set (0.01 sec)


How to add an image in Tkinter?

This code works for me, also you should consider if you have any other button or labels in that window and you not use .place() it will not work properly.

from Tkinter import*
from PIL import Image, ImageTk

img  ="path/x.png") 

Python: tf-idf-cosine: to find document similarity

I know its an old post. but I tried the package. here is my code to find the cosine similarity. The question was how will you calculate the cosine similarity with this package and here is my code for that

from sklearn.feature_extraction.text import CountVectorizer
from sklearn.metrics.pairwise import cosine_similarity
from sklearn.feature_extraction.text import TfidfVectorizer

f = open("/root/Myfolder/scoringDocuments/doc1")
doc1 = str.decode(, "UTF-8", "ignore")
f = open("/root/Myfolder/scoringDocuments/doc2")
doc2 = str.decode(, "UTF-8", "ignore")
f = open("/root/Myfolder/scoringDocuments/doc3")
doc3 = str.decode(, "UTF-8", "ignore")

train_set = ["president of India",doc1, doc2, doc3]

tfidf_vectorizer = TfidfVectorizer()
tfidf_matrix_train = tfidf_vectorizer.fit_transform(train_set)  #finds the tfidf score with normalization
print "cosine scores ==> ",cosine_similarity(tfidf_matrix_train[0:1], tfidf_matrix_train)  #here the first element of tfidf_matrix_train is matched with other three elements

Here suppose the query is the first element of train_set and doc1,doc2 and doc3 are the documents which I want to rank with the help of cosine similarity. then I can use this code.

Also the tutorials provided in the question was very useful. Here are all the parts for it part-I,part-II,part-III

the output will be as follows :

[[ 1.          0.07102631  0.02731343  0.06348799]]

here 1 represents that query is matched with itself and the other three are the scores for matching the query with the respective documents.

Is ncurses available for windows?

Such a thing probably does not exist "as-is". It doesn't really exist on Linux or other UNIX-like operating systems either though.

ncurses is only a library that helps you manage interactions with the underlying terminal environment. But it doesn't provide a terminal emulator itself.

The thing that actually displays stuff on the screen (which in your requirement is listed as "native resizable win32 windows") is usually called a Terminal Emulator. If you don't like the one that comes with Windows (you aren't alone; no person on Earth does) there are a few alternatives. There is Console, which in my experience works sometimes and appears to just wrap an underlying Windows terminal emulator (I don't know for sure, but I'm guessing, since there is a menu option to actually get access to that underlying terminal emulator, and sure enough an old crusty Windows/DOS box appears which mirrors everything in the Console window).

A better option

Another option, which may be more appealing is puttycyg. It hooks in to Putty (which, coming from a Linux background, is pretty close to what I'm used to, and free) but actually accesses an underlying cygwin instead of the Windows command interpreter (CMD.EXE). So you get all the benefits of Putty's awesome terminal emulator, as well as nice ncurses (and many other) libraries provided by cygwin. Add a couple command line arguments to the Shortcut that launches Putty (or the Batch file) and your app can be automatically launched without going through Putty's UI.

VBA copy rows that meet criteria to another sheet

After formatting the previous answer to my own code, I have found an efficient way to copy all necessary data if you are attempting to paste the values returned via AutoFilter to a separate sheet.

With .Range("A1:A" & LastRow)
    .Autofilter Field:=1, Criteria1:="=*" & strSearch & "*"
End With

In this block, the AutoFilter finds all of the rows that contain the value of strSearch and filters out all of the other values. It then copies the cells (using offset in case there is a header), opens the destination sheet and pastes the values to the specified range on the destination sheet.

How to clear Tkinter Canvas?

Yes, I believe you are creating thousands of objects. If you're looking for an easy way to delete a bunch of them at once, use canvas tags described here. This lets you perform the same operation (such as deletion) on a large number of objects.

How to remove all white spaces in java

boolean flag = true;
while(flag) {
    s = s.replaceAll(" ", "");
    if (!s.contains(" "))
        flag = false;
return s;

What does -XX:MaxPermSize do?

-XX:PermSize -XX:MaxPermSize are used to set size for Permanent Generation.

Permanent Generation: The Permanent Generation is where class files are kept. These are the result of compiled classes and JSP pages. If this space is full, it triggers a Full Garbage Collection. If the Full Garbage Collection cannot clean out old unreferenced classes and there is no room left to expand the Permanent Space, an Out-of- Memory error (OOME) is thrown and the JVM will crash.

What data type to use for money in Java?

BigDecimal can be used, good explanation of why to not use Float or Double can be seen here: Why not use Double or Float to represent currency?

IF formula to compare a date with current date and return result

The formula provided by Blake doesn't seem to work for me. For past dates it returns due in xx days and for future dates, it returns overdue. Also, it will only return 15 days overdue, when it could actually be 30, 60 90+.

I created this, which seems to work and provides 'Due in xx days', 'Overdue xx days' and 'Due Today'.

=IF(ISBLANK(O10),"",IF(DAYS(TODAY(),O10)<0,CONCATENATE("Due in ",-DAYS(TODAY(),O10)," Days"),IF(DAYS(TODAY(),O10)>0,CONCATENATE("Overdue ",DAYS(TODAY(),O10)," Days"),"Due Today")))

Spring Maven clean error - The requested profile "pom.xml" could not be activated because it does not exist

Goto Properties -> maven Remove the pom.xml from the activate profiles and follow the below steps.

Steps :

  1. Delete the .m2 repository
  2. Restart the Eclipse IDE
  3. Refresh and Rebuild it

BasicHttpBinding vs WsHttpBinding vs WebHttpBinding

You're comparing apples to oranges here:

  • webHttpBinding is the REST-style binding, where you basically just hit a URL and get back a truckload of XML or JSON from the web service

  • basicHttpBinding and wsHttpBinding are two SOAP-based bindings which is quite different from REST. SOAP has the advantage of having WSDL and XSD to describe the service, its methods, and the data being passed around in great detail (REST doesn't have anything like that - yet). On the other hand, you can't just browse to a wsHttpBinding endpoint with your browser and look at XML - you have to use a SOAP client, e.g. the WcfTestClient or your own app.

So your first decision must be: REST vs. SOAP (or you can expose both types of endpoints from your service - that's possible, too).

Then, between basicHttpBinding and wsHttpBinding, there differences are as follows:

  • basicHttpBinding is the very basic binding - SOAP 1.1, not much in terms of security, not much else in terms of features - but compatible to just about any SOAP client out there --> great for interoperability, weak on features and security

  • wsHttpBinding is the full-blown binding, which supports a ton of WS-* features and standards - it has lots more security features, you can use sessionful connections, you can use reliable messaging, you can use transactional control - just a lot more stuff, but wsHttpBinding is also a lot *heavier" and adds a lot of overhead to your messages as they travel across the network

For an in-depth comparison (including a table and code examples) between the two check out this codeproject article: Differences between BasicHttpBinding and WsHttpBinding

Graph implementation C++

This question is ancient but for some reason I can't seem to get it out of my mind.

While all of the solutions do provide an implementation of graphs, they are also all very verbose. They are simply not elegant.

Instead of inventing your own graph class all you really need is a way to tell that one point is connected to another -- for that, std::map and std::unordered_map work perfectly fine. Simply, define a graph as a map between nodes and lists of edges. If you don't need extra data on the edge, a list of end nodes will do just fine.

Thus a succinct graph in C++, could be implemented like so:

using graph = std::map<int, std::vector<int>>;

Or, if you need additional data,

struct edge {
    int nodes[2];
    float cost; // add more if you need it

using graph = std::map<int, std::vector<edge>>;

Now your graph structure will plug nicely into the rest of the language and you don't have to remember any new clunky interface -- the old clunky interface will do just fine.

No benchmarks, but I have a feeling this will also outperform the other suggestions here.

NB: the ints are not indices -- they are identifiers.

How can I center an image in Bootstrap?

Image by default is displayed as inline-block, you need to display it as block in order to center it with .mx-auto. This can be done with built-in .d-block:

<div class="container">
    <div class="row">
        <div class="col-4">
            <img class="mx-auto d-block" src="...">  

Or leave it as inline-block and wrapped it in a div with .text-center:

<div class="container">
    <div class="row">
        <div class="col-4">
          <div class="text-center">
            <img src="..."> 

I made a fiddle showing both ways. They are documented here as well.

Git: How to remove file from index without deleting files from any repository

My solution is to pull on the other working copy and then do:

git log --pretty="format:" --name-only -n1 | xargs git checkout HEAD^1

which says get all the file paths in the latest comment, and check them out from the parent of HEAD. Job done.

What is the difference between Tomcat, JBoss and Glassfish?

It seems a bit discouraging to use Tomcat when you read these answers. However what most fail to mention is that you can get to identical or almost identical use cases with tomcat but that requires you to add the libraries needed (through Maven or whatever include system you use).

I have been running tomcat with JPA, EJBs with very small configuration efforts.

Resize svg when window is resized in d3.js

   // Container class to make it responsive.
   .classed("svg-container", true) 
   // Responsive SVG needs these 2 attributes and no width and height attr.
   .attr("preserveAspectRatio", "xMinYMin meet")
   .attr("viewBox", "0 0 600 400")
   // Class to make it responsive.
   .classed("svg-content-responsive", true)
   // Fill with a rectangle for visualization.
   .classed("rect", true)
   .attr("width", 600)
   .attr("height", 400);
.svg-container {
  display: inline-block;
  position: relative;
  width: 100%;
  padding-bottom: 100%; /* aspect ratio */
  vertical-align: top;
  overflow: hidden;
.svg-content-responsive {
  display: inline-block;
  position: absolute;
  top: 10px;
  left: 0;

svg .rect {
  fill: gold;
  stroke: steelblue;
  stroke-width: 5px;
<script src=""></script>

<div id="chartId"></div>

Getting result of dynamic SQL into a variable for sql-server

    AND OBJECT_NAME  =''' || vTBL_CLIENT_MASTER || '''';

How do I check if a C++ std::string starts with a certain string, and convert a substring to an int?

In case you need C++11 compatibility and cannot use boost, here is a boost-compatible drop-in with an example of usage:

#include <iostream>
#include <string>

static bool starts_with(const std::string str, const std::string prefix)
    return ((prefix.size() <= str.size()) && std::equal(prefix.begin(), prefix.end(), str.begin()));

int main(int argc, char* argv[])
    bool usage = false;
    unsigned int foos = 0; // default number of foos if no parameter was supplied

    if (argc > 1)
        const std::string fParamPrefix = "-f="; // shorthand for foo
        const std::string fooParamPrefix = "--foo=";

        for (unsigned int i = 1; i < argc; ++i)
            const std::string arg = argv[i];

                if ((arg == "-h") || (arg == "--help"))
                    usage = true;
                } else if (starts_with(arg, fParamPrefix)) {
                    foos = std::stoul(arg.substr(fParamPrefix.size()));
                } else if (starts_with(arg, fooParamPrefix)) {
                    foos = std::stoul(arg.substr(fooParamPrefix.size()));
            } catch (std::exception& e) {
                std::cerr << "Invalid parameter: " << argv[i] << std::endl << std::endl;
                usage = true;

    if (usage)
        std::cerr << "Usage: " << argv[0] << " [OPTION]..." << std::endl;
        std::cerr << "Example program for parameter parsing." << std::endl << std::endl;
        std::cerr << "  -f, --foo=N   use N foos (optional)" << std::endl;
        return 1;

    std::cerr << "number of foos given: " << foos << std::endl;

Reading a UTF8 CSV file with Python

Looking at the Latin-1 unicode table, I see the character code 00E9 "LATIN SMALL LETTER E WITH ACUTE". This is the accented character in your sample data. A simple test in Python shows that UTF-8 encoding for this character is different from the unicode (almost UTF-16) encoding.

>>> u'\u00e9'
>>> u'\u00e9'.encode('utf-8')

I suggest you try to encode("UTF-8") the unicode data before calling the special unicode_csv_reader(). Simply reading the data from a file might hide the encoding, so check the actual character values.

How to set background color of view transparent in React Native

The following works fine:

backgroundColor: 'rgba(52, 52, 52, alpha)'

You could also try:

backgroundColor: 'transparent'

SQL "select where not in subquery" returns no results

select *,
(select COUNT(ID)  from ProductMaster where ProductMaster.CatID = CategoryMaster.ID) as coun 
from CategoryMaster

How to check file MIME type with javascript before upload?

Here is a Typescript implementation that supports webp. This is based on the JavaScript answer by

interface Mime {
  mime: string;
  pattern: (number | undefined)[];

// tslint:disable number-literal-format
// tslint:disable no-magic-numbers
const imageMimes: Mime[] = [
    mime: 'image/png',
    pattern: [0x89, 0x50, 0x4e, 0x47]
    mime: 'image/jpeg',
    pattern: [0xff, 0xd8, 0xff]
    mime: 'image/gif',
    pattern: [0x47, 0x49, 0x46, 0x38]
    mime: 'image/webp',
    pattern: [0x52, 0x49, 0x46, 0x46, undefined, undefined, undefined, undefined, 0x57, 0x45, 0x42, 0x50, 0x56, 0x50],
  // You can expand this list @see
// tslint:enable no-magic-numbers
// tslint:enable number-literal-format

function isMime(bytes: Uint8Array, mime: Mime): boolean {
  return mime.pattern.every((p, i) => !p || bytes[i] === p);

function validateImageMimeType(file: File, callback: (b: boolean) => void) {
  const numBytesNeeded = Math.max( => m.pattern.length));
  const blob = file.slice(0, numBytesNeeded); // Read the needed bytes of the file

  const fileReader = new FileReader();

  fileReader.onloadend = e => {
    if (!e || !fileReader.result) return;

    const bytes = new Uint8Array(fileReader.result as ArrayBuffer);

    const valid = imageMimes.some(mime => isMime(bytes, mime));



// When selecting a file on the input
fileInput.onchange = () => {
  const file = fileInput.files && fileInput.files[0];
  if (!file) return;

  validateImageMimeType(file, valid => {
    if (!valid) {
      alert('Not a valid image file.');

<input type="file" id="fileInput">

How to maximize the browser window in Selenium WebDriver (Selenium 2) using C#?

There's an outstanding issue to add this functionality to WebDriver, which can be tracked here:

A workaround would be to use the JavascriptExector as follows:

public void resizeTest() {
((IJavaScriptExecutor)driver).ExecuteScript("window.resizeTo(1024, 768);");

Parsing JSON in Java without knowing JSON format

Take a look at Jacksons built-in tree model feature.

And your code will be:

public void parse(String json)  {
       JsonFactory factory = new JsonFactory();

       ObjectMapper mapper = new ObjectMapper(factory);
       JsonNode rootNode = mapper.readTree(json);  

       Iterator<Map.Entry<String,JsonNode>> fieldsIterator = rootNode.fields();
       while (fieldsIterator.hasNext()) {

           Map.Entry<String,JsonNode> field =;
           System.out.println("Key: " + field.getKey() + "\tValue:" + field.getValue());

Including a css file in a blade template?

<link rel="stylesheet" href="{{ URL::asset('css/styles.css') }}">

It will search for the file in your project public folder

How to query all the GraphQL type fields without writing a long query?

Unfortunately what you'd like to do is not possible. GraphQL requires you to be explicit about specifying which fields you would like returned from your query.

cv2.imshow command doesn't work properly in opencv-python

I found the answer that worked for me here:

If you run an interactive ipython session, and want to use highgui windows, do cv2.startWindowThread() first.

In detail: HighGUI is a simplified interface to display images and video from OpenCV code. It should be as easy as:

import cv2
img = cv2.imread("image.jpg")
cv2.imshow("preview", img)

Program does not contain a static 'Main' method suitable for an entry point

Project Properties \ Output file -> Select Class Library :)

change cursor from block or rectangle to line?

please Press fn +ins key together

from jquery $.ajax to angular $http

We can implement ajax request by using http service in AngularJs, which helps to read/load data from remote server.

$http service methods are listed below,


One of the Example:

        .success(function(response) {
            $scope.getting =; // is an array

        // Error callback will trigger

What is the difference between angular-route and angular-ui-router?

ui router make your life easier! You can add it to you AngularJS application via injecting it into your applications...

ng-route comes as part of the core AngularJS, so it's simpler and gives you fewer options...

Look at here to understand ng-route better:

Also when using it, don't forget to use: ngView ..

ng-ui-router is different but: but gives you more options....

Open JQuery Datepicker by clicking on an image w/ no input field

<img src='someimage.gif' id="datepicker" />
<input type="hidden" id="dp" />

 $(document).on("click", "#datepicker", function () {
    dateFormat: 'dd-mm-yy',
    minDate: 'today'}).datepicker( "show" ); 

you just add this code for image clicking or any other html tag clicking event. This is done by initiate the datepicker function when we click the trigger.

Is there a simple way to remove unused dependencies from a maven pom.xml?

You can use dependency:analyze -DignoreNonCompile

This will print a list of used undeclared and unused declared dependencies (while ignoring runtime/provided/test/system scopes for unused dependency analysis.)

** Be careful while using this, some libraries used at runtime are considered as unused **

For more details refer this link

Simple way to query connected USB devices info in Python?

If you are working on windows, you can use pywin32 (old link: see update below).

I found an example here:

import win32com.client

wmi = win32com.client.GetObject ("winmgmts:")
for usb in wmi.InstancesOf ("Win32_USBHub"):
    print usb.DeviceID

Update Apr 2020:

'pywin32' release versions from 218 and up can be found here at github. Current version 227.

Set proxy through windows command line including login parameters

If you are using Microsoft windows environment then you can set a variable named HTTP_PROXY, FTP_PROXY, or HTTPS_PROXY depending on the requirement.

I have used following settings for allowing my commands at windows command prompt to use the browser proxy to access internet.

set HTTP_PROXY=http://proxy_userid:proxy_password@proxy_ip:proxy_port

The parameters on right must be replaced with actual values.

Once the variable HTTP_PROXY is set, all our subsequent commands executed at windows command prompt will be able to access internet through the proxy along with the authentication provided.

Additionally if you want to use ftp and https as well to use the same proxy then you may like to the following environment variables as well.



urlencoded Forward slash is breaking URL

$encoded_url = str_replace('%2F', '/', urlencode($url));

Android Studio: Module won't show up in "Edit Configuration"


Files > Sync Project with Gradle Files or Files > Sync with File System Should do the trick.

Design DFA accepting binary strings divisible by a number 'n'

You can build DFA using simple modular arithmetics. We can interpret w which is a string of k-ary numbers using a following rule

V[0] = 0
V[i] = (S[i-1] * k) + to_number(str[i])

V[|w|] is a number that w is representing. If modify this rule to find w mod N, the rule becomes this.

V[0] = 0
V[i] = ((S[i-1] * k) + to_number(str[i])) mod N

and each V[i] is one of a number from 0 to N-1, which corresponds to each state in DFA. We can use this as the state transition.

See an example.

k = 2, N = 5

| V | (V*2 + 0) mod 5     | (V*2 + 1) mod 5     |
| 0 | (0*2 + 0) mod 5 = 0 | (0*2 + 1) mod 5 = 1 |
| 1 | (1*2 + 0) mod 5 = 2 | (1*2 + 1) mod 5 = 3 |
| 2 | (2*2 + 0) mod 5 = 4 | (2*2 + 1) mod 5 = 0 |
| 3 | (3*2 + 0) mod 5 = 1 | (3*2 + 1) mod 5 = 2 |
| 4 | (4*2 + 0) mod 5 = 3 | (4*2 + 1) mod 5 = 4 |

k = 3, N = 5

| V | 0 | 1 | 2 |
| 0 | 0 | 1 | 2 |
| 1 | 3 | 4 | 0 |
| 2 | 1 | 2 | 3 |
| 3 | 4 | 0 | 1 |
| 4 | 2 | 3 | 4 |

Now you can see a very simple pattern. You can actually build a DFA transition just write repeating numbers from left to right, from top to bottom, from 0 to N-1.

Number prime test in JavaScript

Cool version:

const isPrime = n => ![...Array(n).keys()].slice(2).map(i => !(n%i)).includes(true) && ![0,1].includes(n)

Directing print output to a .txt file

Another method without having to update your Python code at all, would be to redirect via the console.

Basically, have your Python script print() as usual, then call the script from the command line and use command line redirection. Like this:

$ python ./ > output.txt

Your output.txt file will now contain all output from your Python script.

To address the comment; for Windows, change the forward-slash to a backslash.
(i.e. .\

How can I select item with class within a DIV?



JS Fiddle demo.



JS Fiddle demo.


$('#mydiv .myclass');

JS Fiddle demo.


Good to learn from the find() documentation:

The .find() and .children() methods are similar, except that the latter only travels a single level down the DOM tree.

Accessing a resource via codebehind in WPF

I got the resources on C# (Desktop WPF W/ .NET Framework 4.8) using the code below


How to use Regular Expressions (Regex) in Microsoft Excel both in-cell and loops

I don't want to have to enable a reference library as I need my scripts to be portable. The Dim foo As New VBScript_RegExp_55.RegExp line caused User Defined Type Not Defined errors, but I found a solution that worked for me.

Update RE comments w/ @chrisneilsen :

I was under the impression that enabling a reference library was tied to the local computers settings, but it is in fact, tied directly to the workbook. So, you can enable a reference library, share a macro enabled workbook and the end user wouldn't have to enable the library as well. Caveat: The advantage to Late Binding is that the developer does not have to worry about the wrong version of an object library being installed on the user's computer. This likely would not be an issue w/ the VBScript_RegExp_55.RegExp library, but I'm not sold that the "performance" benifit is worth it for me at this time, as we are talking imperceptible milliseconds in my code. I felt this deserved an update to help others understand. If you enable the reference library, you can use "early bind", but if you don't, as far as I can tell, the code will work fine, but you need to "late bind" and loose on some performance/debugging features.


What you'll want to do is put an example string in cell A1, then test your strPattern. Once that's working adjust then rng as desired.

Public Sub RegExSearch()
    Dim regexp As Object
    'Dim regex As New VBScript_RegExp_55.regexp 'Caused "User Defined Type Not Defined" Error
    Dim rng As Range, rcell As Range
    Dim strInput As String, strPattern As String
    Set regexp = CreateObject("vbscript.regexp")
    Set rng = ActiveSheet.Range("A1:A1")
    strPattern = "([a-z]{2})([0-9]{8})"
    'Search for 2 Letters then 8 Digits Eg: XY12345678 = Matched

    With regexp
        .Global = False
        .MultiLine = False
        .ignoreCase = True
        .Pattern = strPattern
    End With

    For Each rcell In rng.Cells

        If strPattern <> "" Then
            strInput = rcell.Value

            If regexp.test(strInput) Then
                MsgBox rcell & " Matched in Cell " & rcell.Address
                MsgBox "No Matches!"
            End If
        End If
End Sub

Programmatically Creating UILabel

For swift

var label = UILabel(frame: CGRect(x: 0, y: 0, width: 250, height: 50))
label.textAlignment = .left
label.text = "This is a Label"

How do I put variables inside javascript strings?

Note, from 2015 onwards, just use backticks for templating

let a = `hello ${name}`    // NOTE!!!!!!!! ` not ' or "

Note that it is a backtick, not a quote.

If you want to have something similar, you could create a function:

function parse(str) {
    var args = [], 1),
        i = 0;

    return str.replace(/%s/g, () => args[i++]);


s = parse('hello %s, how are you doing', my_name);

This is only a simple example and does not take into account different kinds of data types (like %i, etc) or escaping of %s. But I hope it gives you some idea. I'm pretty sure there are also libraries out there which provide a function like this.

SQL SERVER: Check if variable is null and then assign statement for Where Clause

Try the following:

if ((select VisitCount from PageImage where PID=@pid and PageNumber=5) is NULL)
    update PageImage
    set VisitCount=1
    where PID=@pid and PageNumber=@pageno
    update PageImage 
    set VisitCount=VisitCount+1
    where PID=@pid and PageNumber=@pageno

android.content.Context.getPackageName()' on a null object reference

android API level 23.



instead of


getActivity() gives the parent Activity, a Context object

Here You can use


instead of

getActivity() / getApplicationContext()

Setting up connection string in ASP.NET to SQL SERVER

in header

using System.Configuration;

in code

SqlConnection conn = new SqlConnection(*ConfigurationManager.ConnectionStrings["connstrname"].ConnectionString*);

How to auto resize and adjust Form controls with change in resolution

Use Dock and Anchor properties. Here is a good article. Note that these will handle changes when maximizing/minimizing. That is a little different that if the screen resolution changes, but it will be along the same idea.

href image link download on click

No, it isn't. You will need something on the server to send a Content-Disposition header to set the file as an attachment instead of being inline. You could do this with plain Apache configuration though.

I've found an example of doing it using mod_rewrite, although I know there is a simpler way.

Getting URL

I'm not aware of any way to programmatically create these URLs, but the existing username space ( works on also (e.g. )

How do I see the extensions loaded by PHP?

      echo "<pre>";
      echo "<pre/>";

Perform an action in every sub-directory using Bash

The simplest non recursive way is:

for d in */; do
    echo "$d"

The / at the end tells, use directories only.

There is no need for

  • find
  • awk
  • ...

python pandas remove duplicate columns

I ran into this problem where the one liner provided by the first answer worked well. However, I had the extra complication where the second copy of the column had all of the data. The first copy did not.

The solution was to create two data frames by splitting the one data frame by toggling the negation operator. Once I had the two data frames, I ran a join statement using the lsuffix. This way, I could then reference and delete the column without the data.

- E

List file names based on a filename pattern and file content?

It can be done without find as well by using grep's "--include" option.

grep man page says:

Search only files whose base name matches GLOB (using wildcard matching as described under --exclude).

So to do a recursive search for a string in a file matching a specific pattern, it will look something like this:

grep -r --include=<pattern> <string> <directory>

For example, to recursively search for string "mytarget" in all Makefiles:

grep -r --include="Makefile" "mytarget" ./

Or to search in all files starting with "Make" in filename:

grep -r --include="Make*" "mytarget" ./

How to use in jQuery :not and hasClass() to get a specific element without a class

You can also use jQuery - is(selector) Method:

var lastOpenSite = $(this).siblings().is(':not(.closedTab)');

Has been compiled by a more recent version of the Java Runtime (class file version 57.0)

I had similar problem with IntelliJ when tried to run some Groovy scripts. Here is how I solved it.

Go to "Project Structure"-> "Project" -> "Project language level" and select "SDK default". This should use the same SDK for all project modules.

set div height using jquery (stretch div height)

You can bind function as follows, instead of init on load

$("div").css("height", $(window).height());
$(?window?).bind("resize",function() {
    $("div").css("height", $(window).height());

Remove '\' char from string c#

Why not simply this?

resultString = Regex.Replace(subjectString, @"\\", "");

How do I start/stop IIS Express Server?

to stop IIS manually:

  1. go to start menu
  2. type in IIS

you get a search result for the manager (Internet Information Services (IIS) manager, on the right side of it there are restart/stop/start buttons.

If you don't want IIS to start on startup because its really annoying..:

  1. go to start menu.
  2. click control panel.
  3. click programs.
  4. turn windows features on or off
  5. wait until the list is loaded
  6. search for Internet Information Services (IIS).
  7. uncheck the box.
  8. Wait until it's done with the changes.
  9. restart computer, but then again the info box will tell you to do that anyways (you can leave this for later if you want to).

oh and IIS and xampp basically do the same thing just in a bit different way. ANd if you have Xampp for your projects then its not really all that nessecary to leave it on if you don't ever use it anyways.

How Should I Declare Foreign Key Relationships Using Code First Entity Framework (4.1) in MVC3?

If you have an Order class, adding a property that references another class in your model, for instance Customer should be enough to let EF know there's a relationship in there:

public class Order
    public int ID { get; set; }

    // Some other properties

    // Foreign key to customer
    public virtual Customer Customer { get; set; }

You can always set the FK relation explicitly:

public class Order
    public int ID { get; set; }

    // Some other properties

    // Foreign key to customer
    public string CustomerID { get; set; }
    public virtual Customer Customer { get; set; }

The ForeignKeyAttribute constructor takes a string as a parameter: if you place it on a foreign key property it represents the name of the associated navigation property. If you place it on the navigation property it represents the name of the associated foreign key.

What this means is, if you where to place the ForeignKeyAttribute on the Customer property, the attribute would take CustomerID in the constructor:

public string CustomerID { get; set; }
public virtual Customer Customer { get; set; }

EDIT based on Latest Code You get that error because of this line:

public Patient Patient { get; set; }

EF will look for a property called Parent to use it as the Foreign Key enforcer. You can do 2 things:

1) Remove the ForeignKeyAttribute and replace it with the RequiredAttribute to mark the relation as required:

public virtual Patient Patient { get; set; }

Decorating a property with the RequiredAttribute also has a nice side effect: The relation in the database is created with ON DELETE CASCADE.

I would also recommend making the property virtual to enable Lazy Loading.

2) Create a property called Parent that will serve as a Foreign Key. In that case it probably makes more sense to call it for instance ParentID (you'll need to change the name in the ForeignKeyAttribute as well):

public int ParentID { get; set; }

In my experience in this case though it works better to have it the other way around:

public int ParentID { get; set; }

public virtual Patient Patient { get; set; }

What are "named tuples" in Python?

Try this:


Basically, namedtuples are easy to create, lightweight object types. They turn tuples into convenient containers for simple tasks. With namedtuples, you don’t have to use integer indices for accessing members of a tuple.


Code 1:

>>> from collections import namedtuple

>>> Point = namedtuple('Point','x,y')

>>> pt1 = Point(1,2)

>>> pt2 = Point(3,4)

>>> dot_product = ( pt1.x * pt2.x ) +( pt1.y * pt2.y )

>>> print dot_product

Code 2:

>>> from collections import namedtuple

>>> Car = namedtuple('Car','Price Mileage Colour Class')

>>> xyz = Car(Price = 100000, Mileage = 30, Colour = 'Cyan', Class = 'Y')

>>> print xyz

Car(Price=100000, Mileage=30, Colour='Cyan', Class='Y')
>>> print xyz.Class

Resource interpreted as stylesheet but transferred with MIME type text/html (seems not related with web server)

I started to get the issue today only on chrome and not safari for the same project/url for my goormide container (node.js)

After trying several suggestions above which didn't appear to work and backtracking on some code changes I made from yesterday to today which also made no difference I ended up in the chrome settings clicking:


2.scroll down to bottom, select: "Advanced";

3.scroll down to bottom, select: "Restore settings to their original defaults";

That appears to have fixed the problem as I no longer get the warning/error in the console and the page displays as it should. Reading the posts above it appears the issue can occur from any number of sources so the settings reset is a potential generic fix. Cheers

Install a Nuget package in Visual Studio Code

Nuget Gallery provides a GUI similar to the full Visual Studio. See below.

enter image description here

How To Use:

  1. Install Nuget Gallery from extension marketplace.
  2. Launch from the menu bar View > Command Palette or ??P (Ctrl+Shift+P on Windows and Linux). Type Nuget: Open Gallery.
  3. The GUI above is displayed. You can filter just like in regular Visual Studio.
  4. Make sure the .csproj file checkbox is selected, select version from dropdown, and click install button.


Earlier versions, as noted in the comments, had an issue where the .csproj checkbox was not visible when a package in the csproj file was missing a version number like below.

<PackageReference Include="Microsoft.AspNetCore.App" />

This has been fixed in newer versions of the extension so if you have an older version with this issue, please update it to the latest version.

How To Get Selected Value From UIPickerView

You can get it in the following manner:

NSInteger row;
NSArray *repeatPickerData;
UIPickerView *repeatPickerView;

row = [repeatPickerView selectedRowInComponent:0];
self.strPrintRepeat = [repeatPickerData objectAtIndex:row];

How to return values in javascript

It's difficult to tell what you're actually trying to do and if this is what you really need but you might also use a callback:

function myFunction(value1,callback)
     //Do stuff and 

     if(typeof callback == 'function'){

myFunction("1", function(value2, value3){
    if(value2 && value3)
    //Do some stuff

How to set a cron job to run every 3 hours

The unix setup should be like the following:

 0 */3 * * * sh cron/

good reference for how to set various settings in cron at:

Android Relative Layout Align Center

I hope this will work


  <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android=""
    android:paddingRight="15dp" >

        android:src="@drawable/ic_launcher" />

        android:text="320" />

        android:text="Place Name"
        android:textStyle="bold" />


Best way to repeat a character in C#

var str = new string(Enumerable.Repeat('\t', numTabs).ToArray());

How do I initialize Kotlin's MutableList to empty MutableList?

I do like below to :

var book: MutableList<Books> = mutableListOf()

/** Returns a new [MutableList] with the given elements. */

public fun <T> mutableListOf(vararg elements: T): MutableList<T>
    = if (elements.size == 0) ArrayList() else ArrayList(ArrayAsCollection(elements, isVarargs = true))

return in for loop or outside loop

Now someone told me that this is not very good programming because I use the return statement inside a loop and this would cause garbage collection to malfunction.

That's incorrect, and suggests you should treat other advice from that person with a degree of skepticism.

The mantra of "only have one return statement" (or more generally, only one exit point) is important in languages where you have to manage all resources yourself - that way you can make sure you put all your cleanup code in one place.

It's much less useful in Java: as soon as you know that you should return (and what the return value should be), just return. That way it's simpler to read - you don't have to take in any of the rest of the method to work out what else is going to happen (other than finally blocks).

Creating folders inside a GitHub repository without using Git

Another thing you can do is just drag a folder from your computer into the GitHub repository page. This folder does have to have at least 1 item in it, though.

Javascript (+) sign concatenates instead of giving sum of variables

Another alternative could be using:

divID = "question-" + (i - -1);

Subtracting a negative is the same as adding, and a minus cannot be used for concatenation

Edit: Forgot that brackets are still necessary since code is read from left to right.

Error: Main method not found in class Calculate, please define the main method as: public static void main(String[] args)

From the docs

In the Java programming language, every application must contain a main method whose signature is:

public static void main(String[] args)

The modifiers public and static can be written in either order (public static or static public), but the convention is to use public static as shown above. You can name the argument anything you want, but most programmers choose "args" or "argv".

As you say:

error: missing method body, or declare abstract public static void main(String[] args); ^ this is what i got after i added it after the class name

You probably haven't declared main with a body (as ';" would suggest in your error).

You need to have main method with a body, which means you need to add { and }:

public static void main(String[] args) {


Add it inside your class definition.

Although sometimes error messages are not very clear, most of the time they contain enough information to point to the issue. Worst case, you can search internet for the error message. Also, documentation can be really helpful.

HTTP Error 401.2 - Unauthorized You are not authorized to view this page due to invalid authentication headers

Open Project properties by selecting project then go to

View>Properties Windows

and make sure Anonymous Authentication is Enabled

enter image description here

'Field required a bean of type that could not be found.' error spring restful API using mongodb

Solved it. So by default, all packages that falls under @SpringBootApplication declaration will be scanned.

Assuming my main class ExampleApplication that has @SpringBootApplication declaration is declared inside com.example.something, then all components that falls under com.example.something is scanned while com.example.applicant will not be scanned.

So, there are two ways to do it based on this question. Use

"com.example.something", "com.example.application"})

That way, the application will scan all the specified components, but I think what if the scale were getting bigger ?

So I use the second approach, by restructuring my packages and it worked ! Now my packages structure became like this.

+-- main/
¦   +-- java/
|       +-- com.example/
|       |   +--
|       +-- com.example.model/
|       |   +--
|       +-- com.example.controller/
|       |   +--
|       |   +--
|       +-- com.example.service/
|           +--
+-- resources/

TypeError: a bytes-like object is required, not 'str' in python and CSV

just change wb to w




Sass Variable in CSS calc() function

you can use your verbal #{your verbal}

What is the significance of #pragma marks? Why do we need #pragma marks?

When we have a big/lengthy class say more than couple 100 lines of code we can't see everything on Monitor screen, hence we can't see overview (also called document items) of our class. Sometime we want to see overview of our class; its all methods, constants, properties etc at a glance. You can press Ctrl+6 in XCode to see overview of your class. You'll get a pop-up kind of Window aka Jump Bar.

By default, this jump bar doesn't have any buckets/sections. It's just one long list. (Though we can just start typing when jump Bar appears and it will search among jump bar items). Here comes the need of pragma mark

If you want to create sections in your Jump Bar then you can use pragma marks with relevant description. Now refer snapshot attached in question. There 'View lifeCycle' and 'A section dedicated ..' are sections created by pragma marks