ES6 modules are always in strict mode. To quote the relevant part of [the spec][1]:

&gt; ## 10.2.1 Strict Mode Code

&gt; An ECMAScript Script syntactic unit may be processed using either unrestricted or strict mode syntax and semantics. Code is interpreted as strict mode code in the following situations:
&gt;
* Global code is strict mode code if it begins with a Directive Prologue that contains a Use Strict Directive (see 14.1.1).
* **Module code is always strict mode code.**
* All parts of a ClassDeclaration or a ClassExpression are strict mode code.
* Eval code is strict mode code if it begins with a Directive Prologue that contains a Use Strict Directive or if the call to eval is a direct eval (see 12.3.4.1) that is contained in strict mode code.
* Function code is strict mode code if the associated FunctionDeclaration, FunctionExpression, GeneratorDeclaration, GeneratorExpression, MethodDefinition, or ArrowFunction is contained in strict mode code or if the code that produces the value of the function’s [[ECMAScriptCode]] internal slot begins with a Directive Prologue that contains a Use Strict Directive.
* Function code that is supplied as the arguments to the built-in Function and Generator constructors is strict mode code if the last argument is a String that when processed is a FunctionBody that begins with a Directive Prologue that contains a Use Strict Directive.


  [1]: http://www.ecma-international.org/ecma-262/6.0/#sec-strict-mode-code

I&#39;m now trying to run a simple container with shell (/bin/bash) on a Kubernetes cluster.

I thought that there was a way to keep a container running on a Docker container by using `pseudo-tty` and detach option (`-td` option on `docker run` command).

For example,

    $ sudo docker run -td ubuntu:latest

Is there an option like this in Kubernetes?

I&#39;ve tried running a container by using a `kubectl run-container` command like:

    kubectl run-container test_container ubuntu:latest --replicas=1

But the container exits for a few seconds (just like launching with the `docker run` command without options I mentioned above). And ReplicationController launches it again repeatedly.

Is there a way to keep a container running on Kubernetes like the `-td` options in the `docker run` command?




How can I keep a container running on Kubernetes?

I&#39;m trying to write a wrapper around an api my company is developing.  It&#39;s restful, and using Postman I can send a post request to an endpoint like `http://subdomain.dev.myapi.com/api/v1/auth/` with a username and password as POST data and I am given back a token.  All works as expected.  Now, when I try and do the same from PHP I get back a `GuzzleHttp\Psr7\Response` object, but can&#39;t seem to find the token anywhere inside it as I did with the Postman request.  

The relevant code looks like: 

    $client = new Client([&#39;base_uri&#39; =&gt; &#39;http://companysub.dev.myapi.com/&#39;]);
    $response = $client-&gt;post(&#39;api/v1/auth/&#39;, [
        &#39;form_params&#39; =&gt; [
            &#39;username&#39; =&gt; $user,
            &#39;password&#39; =&gt; $password
        ]
    ]);

    var_dump($response); //or $resonse-&gt;getBody(), etc...

The output of the code above looks something like (warning, incoming wall of text):

    object(guzzlehttp\psr7\response)#36 (6) {
      [&quot;reasonphrase&quot;:&quot;guzzlehttp\psr7\response&quot;:private]=&gt;
      string(2) &quot;ok&quot;
      [&quot;statuscode&quot;:&quot;guzzlehttp\psr7\response&quot;:private]=&gt;
      int(200)
      [&quot;headers&quot;:&quot;guzzlehttp\psr7\response&quot;:private]=&gt;
      array(9) {
        [&quot;connection&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(10) &quot;keep-alive&quot;
        }
        [&quot;server&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(15) &quot;gunicorn/19.3.0&quot;
        }
        [&quot;date&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(29) &quot;sat, 30 may 2015 17:22:41 gmt&quot;
        }
        [&quot;transfer-encoding&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(7) &quot;chunked&quot;
        }
        [&quot;content-type&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(16) &quot;application/json&quot;
        }
        [&quot;allow&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(13) &quot;post, options&quot;
        }
        [&quot;x-frame-options&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(10) &quot;sameorigin&quot;
        }
        [&quot;vary&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(12) &quot;cookie, host&quot;
        }
        [&quot;via&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(9) &quot;1.1 vegur&quot;
        }
      }
      [&quot;headerlines&quot;:&quot;guzzlehttp\psr7\response&quot;:private]=&gt;
      array(9) {
        [&quot;connection&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(10) &quot;keep-alive&quot;
        }
        [&quot;server&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(15) &quot;gunicorn/19.3.0&quot;
        }
        [&quot;date&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(29) &quot;sat, 30 may 2015 17:22:41 gmt&quot;
        }
        [&quot;transfer-encoding&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(7) &quot;chunked&quot;
        }
        [&quot;content-type&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(16) &quot;application/json&quot;
        }
        [&quot;allow&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(13) &quot;post, options&quot;
        }
        [&quot;x-frame-options&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(10) &quot;sameorigin&quot;
        }
        [&quot;vary&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(12) &quot;cookie, host&quot;
        }
        [&quot;via&quot;]=&gt;
        array(1) {
          [0]=&gt;
          string(9) &quot;1.1 vegur&quot;
        }
      }
      [&quot;protocol&quot;:&quot;guzzlehttp\psr7\response&quot;:private]=&gt;
      string(3) &quot;1.1&quot;
      [&quot;stream&quot;:&quot;guzzlehttp\psr7\response&quot;:private]=&gt;
      object(guzzlehttp\psr7\stream)#27 (7) {
        [&quot;stream&quot;:&quot;guzzlehttp\psr7\stream&quot;:private]=&gt;
        resource(40) of type (stream)
        [&quot;size&quot;:&quot;guzzlehttp\psr7\stream&quot;:private]=&gt;
        null
        [&quot;seekable&quot;:&quot;guzzlehttp\psr7\stream&quot;:private]=&gt;
        bool(true)
        [&quot;readable&quot;:&quot;guzzlehttp\psr7\stream&quot;:private]=&gt;
        bool(true)
        [&quot;writable&quot;:&quot;guzzlehttp\psr7\stream&quot;:private]=&gt;
        bool(true)
        [&quot;uri&quot;:&quot;guzzlehttp\psr7\stream&quot;:private]=&gt;
        string(10) &quot;php://temp&quot;
        [&quot;custommetadata&quot;:&quot;guzzlehttp\psr7\stream&quot;:private]=&gt;
        array(0) {
        }
      }
    }

The output from Postman was something like:

    {
        &quot;data&quot; : {
            &quot;token&quot; &quot;fasdfasf-asfasdfasdf-sfasfasf&quot;
        }
    }

Clearly I&#39;m missing something about working with the response objects in Guzzle.  The Guzzle response indicates a 200 status code on the request, so I&#39;m not sure exactly what I need to do to retrieve the returned data.

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

I&#39;m not familiar with ECMAScript 6 yet. I&#39;ve just cloned the React Starter Kit repo, which uses ES6 for application code. I was surprised to see that the linter is [configured][1] to forbid occurences of the `use strict` directive, which I thought was recommended in pre-ES6 JavaScript. So what&#39;s the point?


  [1]: https://github.com/kriasoft/react-starter-kit/blob/master/.eslintrc

Not recommended to use &quot;use strict&quot; in ES6?

<p>I'm not familiar with ECMAScript 6 yet. I've just cloned the React Starter Kit repo, which uses ES6 for application code. I was surprised to see that the linter is <a href="https://github.com/kriasoft/react-starter-kit/blob/master/.eslintrc" target="_blank" rel="noopener noreferrer">configured</a> to forbid occurences of the <code>use strict</code> directive, which I thought was recommended in pre-ES6 JavaScript. So what's the point?</p>


My array is something like this:

    myArray = [
      {group: &quot;one&quot;, color: &quot;red&quot;},
      {group: &quot;two&quot;, color: &quot;blue&quot;},
      {group: &quot;one&quot;, color: &quot;green&quot;},
      {group: &quot;one&quot;, color: &quot;black&quot;}
    ]

I want to convert this into:

    myArray = [
      {group: &quot;one&quot;, color: [&quot;red&quot;, &quot;green&quot;, &quot;black&quot;]}
      {group: &quot;two&quot;, color: [&quot;blue&quot;]}
    ]

So, basically, group by `group`.

I&#39;m trying:

    for (i in myArray){
      var group = myArray[i].group;
      //myArray.push(group, {???})
    }

I just don&#39;t know how to handle the grouping of similar group values.

Group array items using object

I&#39;ve been playing around with Angular 2 for the past few days and wondered if it was possible to provide a dynamic `templateUrl` to the `@View` decorator.

I have tried passing it a function and returning a string form it but the entire function just get&#39;s turned into a string.

I haven&#39;t really used Angular 1.x before either so I don&#39;t know if I&#39;m just going about this in the wrong way, but is this possible, or is there a better way to create dynamic views?

For example I might want to display a form if the user is not logged in, but display a text message if they are logged in.

Something like this doesn&#39;t work:

    @Component({
      selector: &#39;my-component&#39;
    })
    @View({
      // This doesn&#39;t work
      templateUrl: function() {
        return this.isLoggedIn ? &#39;logged-in.html&#39; : &#39;logged-out.html&#39;;
      }
    })
    class MyComponent {
      constructor() {
        this.loggedIn = false;
      }
    }

Any help would be appreciated.

Dynamic template URLs in Angular 2

I&#39;ve been trying to make an experiment to see if the local variables in functions are stored on a stack.

So I wrote a little performance test

    function test(fn, times){
        var i = times;
        var t = Date.now()
        while(i--){
            fn()
        }
        return Date.now() - t;
    } 
    ene
    function straight(){
        var a = 1
        var b = 2
        var c = 3
        var d = 4
        var e = 5
        a = a * 5
        b = Math.pow(b, 10)
        c = Math.pow(c, 11)
        d = Math.pow(d, 12)
        e = Math.pow(e, 25)
    }
    function inversed(){
        var a = 1
        var b = 2
        var c = 3
        var d = 4
        var e = 5
        e = Math.pow(e, 25)
        d = Math.pow(d, 12)
        c = Math.pow(c, 11)
        b = Math.pow(b, 10)
        a = a * 5
    }

I expected to get inversed function work much faster. Instead an amazing result came out.

Untill I test one of the functions it runs 10 times faster than after testing the second one.

Example:
    
    &gt; test(straight, 10000000)
    30
    &gt; test(straight, 10000000)
    32
    &gt; test(inversed, 10000000)
    390
    &gt; test(straight, 10000000)
    392
    &gt; test(inversed, 10000000)
    390
Same behaviour when tested in alternative order.

    &gt; test(inversed, 10000000)
    25
    &gt; test(straight, 10000000)
    392
    &gt; test(inversed, 10000000)
    394


I&#39;ve tested it both in the Chrome browser and in Node.js and I&#39;ve got absolutely no clue why would it happen.
The effect lasts till I refresh the current page or restart Node REPL.

What could be a source of such significant (~12 times worse) performance?

PS. Since it seems to work only in some environemnts please write the environment You&#39;re using to test it.

Mine were:  

OS: Ubuntu 14.04  
Node v0.10.37  
Chrome 43.0.2357.134 (Official Build) (64-bit)  

/Edit  
On Firefox 39 it takes ~5500 ms for each test regardless of the order. It seems to occur only on specific engines.

/Edit2  
Inlining the function to the test function makes it run always the same time.   
Is it possible that there is an optimization that inlines the function parameter if it&#39;s always the same function?

What makes this function run much slower?

If I have an array of urls:

    var urls = [&#39;1.txt&#39;, &#39;2.txt&#39;, &#39;3.txt&#39;]; // these text files contain &quot;one&quot;, &quot;two&quot;, &quot;three&quot;, respectively.

And I want to build an object that looks like this:

    var text = [&#39;one&#39;, &#39;two&#39;, &#39;three&#39;];

I’ve been trying to learn to do this with `fetch`, which of course returns `Promise`s.  

Some things I’ve tried that _don’t_ work:

    var promises = urls.map(url =&gt; fetch(url));
    var texts = [];
    Promise.all(promises)
      .then(results =&gt; {
         results.forEach(result =&gt; result.text()).then(t =&gt; texts.push(t))
      })

This doesn’t look right, and in any case it doesn’t work — I don’t end up with an array [&#39;one&#39;, &#39;two&#39;, &#39;three&#39;].

Is using `Promise.all` the right approach here? 

How can I fetch an array of URLs with Promise.all?

I have some javascript code which looks like this:

    var myClass = {
      ids: {}
      myFunc: function(huge_string) {
         var id = huge_string.substr(0,2);
         ids[id] = true;
      }
    }

Later the function gets called with some large strings (100 MB+). I only want to save a short id which I find in each string. However, the Google Chrome&#39;s substring function (actually regex in my code) only returns a &quot;sliced string&quot; object, which references the original. So after a series of calls to `myFunc`, my chrome tab runs out of memory because the temporary `huge_string` objects are not able to be garbage collected.

How can I make a copy of the string `id` so that a reference to the `huge_string` is not maintained, and the `huge_string` can be garbage collected?

[![enter image description here][1]][1]


  [1]: http://i.stack.imgur.com/pzJai.png

How to force JavaScript to deep copy a string?

When ES6 Arrow functions don&#39;t seem to work for assigning a function to an object with prototype.object. Consider the following examples:

    function Animal(name, type){
     this.name = name;
      this.type = type;
      this.toString = () =&gt; `${this.name} is a ${this.type}`;
      
    }
    var myDog = new Animal(&#39;Max&#39;, &#39;Dog&#39;);
    console.log(myDog.toString()); //Max is a Dog

Using the arrow function explicitly in the object definition works, but using the arrow functions with the Object.prototype syntax does not:

    function Animal2(name, type){
      this.name = name;
      this.type = type;
    }
    Animal2.prototype.toString = () =&gt; `${this.name} is a ${this.type}`;
    
    var myPet2 = new Animal2(&#39;Noah&#39;, &#39;cat&#39;);
    console.log(myPet2.toString()); //is a undefined

Just as a proof of concept, using the Template string syntax with Object.prototype syntax does work:

    function Animal3(name, type){
      this.name = name;
      this.type = type;
    }
    Animal3.prototype.toString = function(){ return `${this.name} is a ${this.type}`;}
    
    var myPet3 = new Animal3(&#39;Joey&#39;, &#39;Kangaroo&#39;);
    console.log(myPet3.toString()); //Joey is a Kangaroo

Am I missing something obvious? I feel that example 2 should work logically, but I am puzzled by the output. I&#39;m guessing it is a scoping issue, but I am thrown off by the output &#39;is a undefined&#39;.

[ES6 Fiddle][1]


  [1]: http://www.es6fiddle.net/ics4dh0m/

ES6 arrow functions not working on the prototype?

This component does work:

    export class Template extends React.Component {
    	render() {
    		return (
    			&lt;div&gt; component &lt;/div&gt;
    		);
    	}
    };
    export default Template;

If i remove last row, it doesn&#39;t work.

    Uncaught TypeError: Cannot read property &#39;toUpperCase&#39; of undefined

I guess, I don&#39;t understand something in es6 syntax. Isn&#39;t it have to export without sign &quot;default&quot;? 

Why es6 react component works only with &quot;export default&quot;?

React router allows react apps to handle `/arbitrary/route`. In order this to work, I need my server to send the React app on any matched route.

But [webpack dev server](http://webpack.github.io/docs/webpack-dev-server.html) doesn&#39;t handle arbitrary end points.

There is a solution here using additional express server.
https://stackoverflow.com/questions/26203725/how-to-allow-for-webpack-dev-server-to-allow-entry-points-from-react-router

But I don&#39;t want to fire up another express server to allow route matching. I just want to tell webpack dev server to match any url and send me my react app. please.

How to tell webpack dev server to serve index.html for any route

Which of the two (or neither/ both) code fragments below should be working in a complete ECMAScript 2015 implementation:

`for (const e of a)`

`for (const i = 0; i &lt; a.length; i += 1)`

From my understanding, the first example should work because `e` is initialized for each iteration. Shouldn&#39;t this also be the case for `i` in the second version?

I&#39;m confused because existing implementations (Babel, IE, Firefox, Chrome, ESLint) do not seem to be consistent and have a complete implementation of `const`, with various behaviours of the two loop variants; I&#39;m also not able to find a concrete point in the standard, so that would be much appreciated.

ECMAScript 2015: const in for loops

Is there a simple way to merge ES6 Maps together (like `Object.assign`)? And while we&#39;re at it, what about ES6 Sets (like `Array.concat`)?

Simplest way to merge ES6 Maps/Sets?

Let&#39;s say I have a variable that I want to export. What&#39;s the difference between

    export const a = 1;

vs

    export let a = 1;

I understand the difference between `const` and `let`, but when you export them, what are the differences?

Javascript ES6 export const vs export let

I was under the impression that this syntax:

    import Router from &#39;react-router&#39;;
    var {Link} = Router;

has the same final result as this:

    import {Link} from &#39;react-router&#39;;

Can someone explain what the difference is?

(I originally thought it was a [React Router Bug][1].)


  [1]: https://github.com/rackt/react-router/issues/2468

ES6 Destructuring and Module imports

I am trying to determine if there are any big differences between these two, other than being able to import with `export default` by just doing:

    import myItem from &#39;myItem&#39;;

And using `export const` I can do:

    import { myItem } from &#39;myItem&#39;;

Are there any differences and/or use cases other than this?


`export const` vs. `export default` in ES6

Is it possible to import javascript module from external url in ES6?

I tried (using babel-node):

    import mymodule from &#39;http://...mysite.../myscript.js&#39;;
    // Error: Cannot find module &#39;http://...mysite.../myscript.js&#39;

ES6: import module from URL

I&#39;ve tried searching the internet for the execution order of imported modules. For instance, let&#39;s say I have the following code:

    import &quot;one&quot;
    import &quot;two&quot;
    console.log(&quot;three&quot;);

Where `one.js` and `two.js` are defined as follows:

    // one.js
    console.log(&quot;one&quot;);
    
    // two.js
    console.log(&quot;two&quot;);

Is the console output guaranteed to be:

    one
    two
    three

Or is it undefined?

Content Type	Original Author	Original Content on Stackoverflow
Question	Midiparse	View Question on Stackoverflow
Solution 1 - Javascript	Kit Sunde	View Answer on Stackoverflow

Not recommended to use "use strict" in ES6?

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

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

How can I keep a container running on Kubernetes?

Attributions