JS variables do not have block scope, they have &quot;function&quot; scope (or sometimes global).

The declaration (but not the assignment) is &quot;hoisted&quot; to the top of the function.

jshint is warning you that you have two such declarations - your code is equivalent to:

    var someVar;
    var someVar;  // warning!
    if (something) {
         someVar = true;
    } else {
         someVar = false;
    }

This is due to hoisting.

In javascript, no matter where you define a new variable with `var`, it moves it to the top of the function you are in.  Your code is producing the following above your if block at the top of the function:

    var someVar;
    var someVar;

Here is a tutorial to explain hoisting:

http://net.tutsplus.com/tutorials/javascript-ajax/quick-tip-javascript-hoisting-explained/

You shouldn&#39;t put `var` declarations in such places.  Put the `var` declaration before the `if`, and then just set &quot;someVar&quot; to a value.

Indeed, here you don&#39;t need an `if` statement at all:

    var someVar = !!(something);

will do the same thing. (The double application of `!` ensures that &quot;someVar&quot; is set to either `true` or `false`, based on the &quot;truthiness&quot; of `something`.)

I have a json type field in postgresql. However I can&#39;t select rows where specific field is null:

Code:

    SELECT *
    FROM   json_array_elements(
      &#39;[{&quot;name&quot;: &quot;Toby&quot;, &quot;occupation&quot;: &quot;Software Engineer&quot;},
        {&quot;name&quot;: &quot;Zaphod&quot;, &quot;occupation&quot;: &quot;Galactic President&quot;} ,
    {&quot;name2&quot;: &quot;Zaphod&quot;, &quot;occupation2&quot;: null} ]&#39;  ) AS elem
    where elem#&gt;&#39;{occupation2}&#39; is null

This should work but I am getting this error:

    ERROR:  operator does not exist: json #&gt; boolean
    LINE 6: where elem#&gt;&#39;{occupation2}&#39; is null

How to query for null values in json field type postgresql?

Consider this code:

    var x = &quot;tesx&quot;.Remove(&#39;x&#39;);

If I run this code, I get this exception:

&gt; startIndex must be less than length of string.

Why can I pass a char instead of an int to this method?
Why don&#39;t I get a compilation error?

![enter image description here][1]

Why does the compiler have this behavior?


  [1]: http://i.stack.imgur.com/wC8kP.png

Why does the string Remove() method allow a char as a parameter?

I have this code:

     if ( something is true ) {
            var someVar = true;
        } else {
           var someVar = false;
        }

JsHint is saying that &quot;someVar was already defined&quot; on the else statement part. Why is this and how do I fix it?

Thanks

Why is Jshint saying &quot;variable already defined&quot; in this if statement?

I have this code:
<pre><code class="hljs language-ini"> if ( something is true ) {
 var someVar = true;
 } else {
 var someVar = false;
 }
</code></pre>
JsHint is saying that "someVar was already defined" on the else statement part. Why is this and how do I fix it?
Thanks

**How can I inspect an element which disappears when my mouse moves away?**
![Example dropdown which disappears][1]

I don&#39;t know it&#39;s ID, class or anything but want to inspect it.

**Solutions I have tried:**

Run jQuery selector inside console `$(&#39;*:contains(&quot;some text&quot;)&#39;)` but didn&#39;t have any luck mainly because the element is not hidden but probably removed from the DOM tree.

Manually inspecting DOM tree for changes gives me nothing as it seems to be just too fast to notice what have changed.

  [1]: http://i.stack.imgur.com/FVOVx.png

**SUCCESS:**

I have been successful with Event breakpoints. Specifically - mousedown in my case. Just go to `Sources-&gt; Event Listener Breakpoints-&gt; Mouse-&gt; mousedown` in Chrome. After that I clicked the element I wanted to inspect and inside `Scope Variables` I saw some useful directions.

How can I inspect disappearing element in a browser?

i keep on getting the error 
/socket.io/socket.io.js 404 (Not Found)
Uncaught ReferenceError: io is not defined

my code is

    var express = require(&#39;express&#39;), http = require(&#39;http&#39;);
    var app = express();
    var server = http.createServer(app);
    var io = require(&#39;socket.io&#39;).listen(server);

    server.listen(3000);

and

    &lt;script src=&quot;/socket.io/socket.io.js&quot;&gt;&lt;/script&gt;

what is the problem ???

any help is welcome!




 

node.js /socket.io/socket.io.js not found

How do you remove the &quot;Showing 1 of N entries&quot; line of text on a dataTable (that is when using the javascript library dataTables? I think I was looking for something along these lines...

     $(&#39;#example&#39;).dataTable({
          &quot;showNEntries&quot; : false
           });

Pretty sure this is a simple one, but cannot seem to find it in the docs.

How to hide &quot;Showing 1 of N Entries&quot; with the dataTables.js library

I need to return true or false if an option in a drop down selected. 

This is my code:

    var active = sort.attr(&#39;selected&#39;) ? return true : return false;

I get an error that the first `return` is unexpected.

Why?



Ternary operator with return statements JavaScript

I have a footerController and codeScannerController with different views.
   
    angular.module(&#39;myApp&#39;).controller(&#39;footerController&#39;, [&quot;$scope&quot;, function($scope) {}]);

    angular.module(&#39;myApp&#39;).controller(&#39;codeScannerController&#39;, [&quot;$scope&quot;, function($scope) {
    console.log(&quot;start&quot;);
    $scope.startScanner = function(){...

When I click on a `&lt;li&gt;` in footer.html I should get this event in codeScannerController.

    &lt;li class=&quot;button&quot; ng-click=&quot;startScanner()&quot;&gt;3&lt;/li&gt;

I think it can be realised with `$on` and `$broadcast`, but I don&#39;t know how and can&#39;t find examples anywhere.

$on and $broadcast in angular

Having a bit of an issue with JShint and the following line of code.

    $location.path(&#39;map-&#39; + map.id + &#39;/venue-&#39; + map.attributes.default_venue.value);

I&#39;m getting the error, `Identifier &#39;default_venue&#39; is not in camel case.` This wouldn&#39;t be a problem normally but I don&#39;t have any control over the variable name - it&#39;s brought in via a JSON API.

Is there any way I could suppress this issue for either the affected variables or on the lines in which they appear?

Apologies if this has been asked before, I&#39;m pretty sure it must have been but I can&#39;t find a solution.

Ignore camelcase variable in JSHint

Hi I am having a trouble when my framework is using jshint to validate my `javascript` code. I have used switch-case without a break statement intentionally, but this portion of code is captured as an error when `jshint` checks. My code is something like below.

        switch (&lt;no&gt;){
        case 1:
            // does something
        case 2:
            //does something more
        default:
            // does something even more
       }

`Error from &#39;jshint&#39; is like Line 203 character 41: Expected a &#39;break&#39; statement before &#39;case&#39;.`
Any thoughts on how to avoid it ? or is it a bad practice to use switch cases in this scenario at all ?

jshint throws a&quot;Expected a &#39;break&#39; statement before &#39;case&#39;&quot;

This is the error I get when using const:

    &lt;error line=&quot;2&quot; column=&quot;1&quot; severity=&quot;warning&quot; message=&quot;&amp;apos;const&amp;apos; is available in ES6 (use esnext option) or Mozilla JS extensions (use moz).&quot; source=&quot;jshint.W104&quot; /&gt;


My code looks like this:

    const Suites = {
        Spade: 1,
        Heart: 2,
        Diamond: 3,
        Club: 4
    };

The code works fine only JSHint is warning me every time.

Why does JSHint throw a warning if I am using const?

In order to turn off linting rule for a particular line in JSHint we use the following rule:

    /* jshint ignore:start*/
    $scope.someVar = ConstructorFunction();
    /* jshint ignore:end */

I have been trying to locate the equivalent of the above for eslint. 
 

Turning off eslint rule for a specific line

I am new to [ESLint][1], and I have successfully integrated ESLint with [IntelliJ][2].

Out of the box, my integration of ESLint did not recognize `node`, but basic review of documentation made clear that by creating the configuration file named `.eslintrc` at the root of my project folder (with the proper IntelliJ setting to access this file) and setting `&quot;node&quot;:true`, ESLint recognizes `node` (i.e., the following complete `.eslintrc` works).

    // Contents of .eslintrc at root of project - support for Node and jQuery
    {
      &quot;env&quot; : {
        &quot;node&quot; : true,
        &quot;jquery&quot; : true
      },
    }

However, ESLint still does not recognize `require()`, as evidenced by this screenshot:

![ESLint does not recognize `require()`][3]

I have done my best in a reasonable amount of time searching for a solution to the basic question of how to get `ESLint` to recognize `require()`.  In particular, I found a possible hint [here][4], where it suggested to add `&quot;amd&quot;:false` in (I presumed) the `.eslintrc` file - but no go.

This seems basic.  How can I get `.eslintrc` to recognize `require()`?

(If, in your answer, you can provide insight how to cover more general cases, that would also be helpful.  Thanks!)


  [1]: http://eslint.org/
  [2]: https://www.jetbrains.com/idea
  [3]: http://i.stack.imgur.com/e766P.png
  [4]: http://bl.ocks.org/cletusw/e01a85e399ab563b1236


Content Type	Original Author	Original Content on Stackoverflow
Question	user2413333	View Question on Stackoverflow
Solution 1 - Javascript	Alnitak	View Answer on Stackoverflow
Solution 2 - Javascript	Erik Christianson	View Answer on Stackoverflow
Solution 3 - Javascript	Pointy	View Answer on Stackoverflow

Why is Jshint saying "variable already defined" in this if statement?

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

Solution 3 - Javascript

Why does the string Remove() method allow a char as a parameter?

How to query for null values in json field type postgresql?

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