[FETCH][1] is polyfill for browsers which don&#39;t have fetch function ([caniuse.com/#search=fetch][2]). It will add fetch function to your browser window object. 

While [isomorphic-fetch][3] is implementation of fetch for both node.js and browser, built on top of fetch polyfill.


  [1]: https://github.com/github/fetch
  [2]: http://caniuse.com/#search=fetch
  [3]: https://github.com/matthew-andrews/isomorphic-fetch

&gt; The Fetch API is currently not implemented consistently across browsers. This module will enable you to use fetch in your Node code in a cross-browser compliant fashion. 

Short answer, isomorphic fetch is a better way of using fetch because it covers a wide range of browsers than the native fetch API.

What I want to do is shown below in 2 stream calls. I want to split a collection into 2 new collections based on some condition. Ideally I want to do it in 1. I&#39;ve seen conditions used for the .map function of streams, but couldn&#39;t find anything for the forEach. What is the best way to achieve what I want?

        animalMap.entrySet().stream()
                .filter(pair-&gt; pair.getValue() != null)
                .forEach(pair-&gt; myMap.put(pair.getKey(), pair.getValue()));

        animalMap.entrySet().stream()
                .filter(pair-&gt; pair.getValue() == null)
                .forEach(pair-&gt; myList.add(pair.getKey()));


How to use if-else logic in Java 8 stream forEach

I&#39;m trying to make jQuery UI work, but it doesn&#39;t. Here&#39;s what happens. 

I&#39;m loading dependencies:

    &lt;script src=&quot;assets/src/js/angular/angular.js&quot;&gt;&lt;/script&gt;
    &lt;script src=&quot;assets/src/js/angular-animate/angular-animate.js&quot;&gt;&lt;/script&gt;
    &lt;script src=&quot;assets/src/js/angular-route/angular-route.js&quot;&gt;&lt;/script&gt;
    &lt;script src=&quot;assets/src/js/jquery/dist/jquery.js&quot;&gt;&lt;/script&gt;
    &lt;script src=&quot;assets/src/js/jquery-ui/jquery-ui.js&quot;&gt;&lt;/script&gt;
    &lt;script src=&quot;assets/src/js/app.js&quot;&gt;&lt;/script&gt;
    &lt;script src=&quot;assets/src/js/main.js&quot;&gt;&lt;/script&gt;

That&#39;s my **main.js** file:

    $(function () {
        $(&quot;input[type=submit]&quot;)
            .button()
            .click(function (event) {
                event.preventDefault();
            });
    });


    $(function () {
        $(&quot;#circum&quot;).buttonset();
    });

    $(function () {
        $(&quot;#dialog-message&quot;).dialog({
            modal: true,
            buttons: {
                Ok: function () {
                    $(this).dialog(&quot;close&quot;);
                }
            }
        });
    });

When I run the code in Brackets jQuery UI is loaded but doesn&#39;t work, however, when I comment my *main.js* file out and then bring it back that&#39;s the error I get in the console and UI is suddenly working. It&#39;s extremely weird.

    jQuery.Deferred exception: elem.getClientRects is not a function TypeError: elem.getClientRects is not a function
    at jQuery.offset (http://127.0.0.1:27530/assets/src/js/jquery/dist/jquery.js:9779:14)
    at Object.getWithinInfo (http://127.0.0.1:27530/assets/src/js/jquery-ui/jquery-ui.js:1157:26)
    at jQuery.$.fn.position (http://127.0.0.1:27530/assets/src/js/jquery-ui/jquery-ui.js:1179:23)
    at _position (http://127.0.0.1:27530/assets/src/js/jquery-ui/jquery-ui.js:8709:17)
    at ._position (http://127.0.0.1:27530/assets/src/js/jquery-ui/jquery-ui.js:415:25)
    at open (http://127.0.0.1:27530/assets/src/js/jquery-ui/jquery-ui.js:8334:8)
    at .open (http://127.0.0.1:27530/assets/src/js/jquery-ui/jquery-ui.js:415:25)
    at _init (http://127.0.0.1:27530/assets/src/js/jquery-ui/jquery-ui.js:8210:9)
    at ._init (http://127.0.0.1:27530/assets/src/js/jquery-ui/jquery-ui.js:415:25)
    at _createWidget (http://127.0.0.1:27530/assets/src/js/jquery-ui/jquery-ui.js:587:8) undefined

I&#39;ve found this thread discussing the issue, but still wasn&#39;t able to fix it.

[Github][1]

Cheers.


  [1]: https://github.com/jquery/jquery/issues/2804

jQuery UI error - f.getClientRects is not a function

I&#39;ve seen two different fetch here:

 - https://github.com/github/fetch

 - https://github.com/matthew-andrews/isomorphic-fetch

Can someone tell me the difference between the two?

PS: I&#39;ve read the README.md but I still didn&#39;t get the difference. Last time I checked, Isomorphic means it has similar form or relation. It still doesn&#39;t make sense to me.

What is the difference between isomorphic-fetch and fetch?

I've seen two different fetch here:
<ul>
<li>
<a href="https://github.com/github/fetch" target="_blank" rel="noopener noreferrer">https://github.com/github/fetch</a>
</li>
<li>
<a href="https://github.com/matthew-andrews/isomorphic-fetch" target="_blank" rel="noopener noreferrer">https://github.com/matthew-andrews/isomorphic-fetch</a>
</li>
</ul>
Can someone tell me the difference between the two?
PS: I've read the README.md but I still didn't get the difference. Last time I checked, Isomorphic means it has similar form or relation. It still doesn't make sense to me.

Executing this snippet in the Chrome console:

&lt;!-- begin snippet: js hide: false console: true --&gt;

&lt;!-- language: lang-js --&gt;

    function foo() {
        return typeof null === &#39;undefined&#39;;
    }
    for(var i = 0; i &lt; 1000; i++) console.log(foo());

&lt;!-- end snippet --&gt;

should print 1000 times `false`, but on some machines will print `false` for a number of iterations, then `true` for the rest. 

[![enter image description here][1]][1]

Why is this happening? Is it just a bug? 


  [1]: http://i.stack.imgur.com/FuFKT.jpg

Why does the value of typeof null change inside a loop?

I have two components:
 
 1. Parent component 
 2. Child component

I was trying to call Child&#39;s method from Parent, I tried this way but couldn&#39;t get a result:

    class Parent extends Component {
      render() {
        return (
          &lt;Child&gt;
            &lt;button onClick={Child.getAlert()}&gt;Click&lt;/button&gt;
          &lt;/Child&gt;
          );
        }
      }

    class Child extends Component {
      getAlert() {
        alert(&#39;clicked&#39;);
      }
     
      render() {
        return (
          &lt;h1 ref=&quot;hello&quot;&gt;Hello&lt;/h1&gt;
        );
      }
    }

Is there a way to call Child&#39;s method from Parent?

Note: Child and Parent components are in two different files.

Call child method from parent

I&#39;m trying to fill the date automatically in a table header, but all I get is 

&gt;&quot;.innerHTML is not a function&quot;

I&#39;ve looked everywhere, and tried put my code at the top and bottom of the page, but nothing works. Help, please!


    window.onload = function() {
      var currentTime = new Date();
      var month = currentTime.getMonth() + 1;
      var day = currentTime.getDate();
      var year = currentTime.getFullYear();
      document.getElementById(&quot;dated&quot;).innerHTML(month + &quot;/&quot; + day + &quot;/&quot; + year);
    };

Error message &quot;.innerHTML is not a function&quot;

Here&#39;s what I have in fruit.ts

    export type Fruit = &quot;Orange&quot; | &quot;Apple&quot; | &quot;Banana&quot;

Now I&#39;m importing fruit.ts in another typescript file. Here&#39;s what I have


    myString:string = &quot;Banana&quot;;
    
    myFruit:Fruit = myString;


When I do

    myFruit = myString;

I get an error:

&gt; Type &#39;string&#39; is not assignable to type &#39;&quot;Orange&quot; | &quot;Apple&quot; |
&gt; &quot;Banana&quot;&#39;

How can I assign a string to a variable of custom type Fruit?

Typescript Type &#39;string&#39; is not assignable to type

I have a function which I have written which basically looks like this:

    function getNextCard(searchTerms) {
      // Setup Some Variables

      // Do a bunch of logic to pick the next card based on termed passed through what I&#39;ll call here as &#39;searchTerms&#39; all of this logic is omitted because it&#39;s not important for my question.
      // ...

      // If we find a next card to give, than give it
      if (nextCardFound)
        return nextCardFound;

      // Otherwise - I&#39;m returning undefined
      return undefined;
    }

**Question: Would it be better to return &quot;null&quot; here?**

I can pass whatever I want back - obviously...  I just wasn&#39;t sure what is the best thing to use.

The code that calls this function knows how to deal with undefined (it actually won&#39;t ever really happen unless something goes horribly wrong)

The reason I&#39;m asking this question is that I heard somewhere something that sounded like &quot;Don&#39;t assign undefined to variables&quot; or something - that it will make it harder to debug.  So, the fact that I can see that `null` gets passed back tells me that the return is working - but basically function similar to `undefined`.

- - -

## Documentation:

[Mozilla Docs](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/undefined) Didn&#39;t answer my question... google didn&#39;t either :\

[This SO Question](https://stackoverflow.com/questions/6604749/what-reason-is-there-to-use-null-instead-of-undefined-in-javascript) - was way too broad for what I&#39;m trying to figure out here.

Is it better to return `undefined` or `null` from a javascript function?

I am using npm &#39;isomorphic-fetch&#39; to send requests. The problem I am experiencing is I am unable to set the content-type of the request header.

I set a content type of application/json , however the request header are being set to text/plain.

    import &#39;isomorphic-fetch&#39;;
    
      sendRequest(url, method, body) {
        const options = {
          method: method,
          headers:{&#39;content-type&#39;: &#39;application/json&#39;},
          mode: &#39;no-cors&#39;
        };
    
        options.body = JSON.stringify(body);
    
        return fetch(url, options);
      }

When I examine the request in my browser the content type is o :

    content-type:text/plain;charset=UTF-8

Can anyone explain why I am unable to set this property?




How to set the content-type of request header when using Fetch APi

Here&#39;s what I have going:

    import &#39;whatwg-fetch&#39;;

    function fetchVehicle(id) {
    	return dispatch =&gt; {
    		return dispatch({
    			type: &#39;FETCH_VEHICLE&#39;,
    			payload: fetch(`http://swapi.co/api/vehicles/${id}/`)
    				.then(status)
    				.then(res =&gt; res.json())			
    				.catch(error =&gt; {
    					throw(error);
    				})
    			});
    	};
    }
    
    function status(res) {
    	if (!res.ok) {
    		return Promise.reject()
    	}
    	return res;
    }

EDIT: The promise doesn&#39;t get rejected, that&#39;s what I&#39;m trying to figure out.

I&#39;m using this [fetch polyfill](https://github.com/github/fetch) in Redux with [redux-promise-middleware](https://github.com/pburtchaell/redux-promise-middleware).

Fetch: reject promise and catch the error if status is not OK?

What is the difference between typical AJAX and Fetch API?

Consider this scenario:

    function ajaxCall(url) {
      return new Promise(function(resolve, reject) {
        var req = new XMLHttpRequest();
        req.open(&#39;GET&#39;, url);

        req.onload = function() {
          if (req.status == 200) {
            resolve(req.response);
          } else {
            reject(Error(req.statusText));
          }
        };
        req.onerror = function() {
          reject(Error(&quot;Network Error&quot;));
        };
        req.send();
      });
    }

    ajaxCall(&#39;www.testSite&#39;).then(x =&gt; {
      console.log(x)
    }) // returns html of site

    fetch(&#39;www.testSite&#39;).then(x =&gt; {
      console.log(x)
    }) // returns object with information about call

This is what the `fetch` call returns:

    Response {type: &quot;cors&quot;, url: &quot;www.testSite&quot;, status: 200, ok: true, statusText: &quot;OK&quot;…}

Why does it return different things?

Is there a way for `fetch` to return the same thing as a typical AJAX call?

Fetch vs. AjaxCall

When I create a brand new project using `react-native init` (RN version 0.29.1) and put a fetch in the render method to the public facebook demo movie API, it throws a `Network Request Failed`. There is a very useless stack trace and I can&#39;t debug network requests in the chrome console. Here is the fetch I&#39;m sending:


    fetch(&#39;http://facebook.github.io/react-native/movies.json&#39;)
          .then((response) =&gt; response.json())
          .then((responseJson) =&gt; {
            return responseJson.movies;
          })
          .catch((error) =&gt; {
            console.error(error);
          });



React Native fetch() Network Request Failed

[Opaque responses](https://fetch.spec.whatwg.org/#concept-filtered-response-opaque) are defined as part of the [Fetch API](https://fetch.spec.whatwg.org/), and represent the result of a request made to a remote origin when [CORS](https://fetch.spec.whatwg.org/#http-cors-protocol) is not enabled.

What practical limitations and &quot;gotchas&quot; exist around how opaque responses can be used, both from JavaScript and as resources on a page?

Content Type	Original Author	Original Content on Stackoverflow
Question	Joshua Rajandiran	View Question on Stackoverflow
Solution 1 - Javascript	Sergey	View Answer on Stackoverflow
Solution 2 - Javascript	Favour Felix Chinemerem	View Answer on Stackoverflow

What is the difference between isomorphic-fetch and fetch?

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

jQuery UI error - f.getClientRects is not a function

How to use if-else logic in Java 8 stream forEach

Attributions