There&#39;s no difference between the two, it&#39;s the same.

It says this in [the docs][1]:

&gt; Array types can be written in one of two ways. In the first, you use
&gt; the type of the elements followed by [] to denote an array of that
&gt; element type:

    let list: number[] = [1, 2, 3];

&gt; The second way uses a generic array type, Array&lt;elemType&gt;:

    let list: Array&lt;number&gt; = [1, 2, 3];

You do need to use the `Array&lt;T&gt;` form when you want to extend it for example:

    class MyArray extends Array&lt;string&gt; { ... }

but you can&#39;t use the other form for this.

  [1]: https://www.typescriptlang.org/docs/handbook/basic-types.html#array

How to get different lighter and darker variations of a given UIColor in Swift?

[![enter image description here][1]][1]


  [1]: http://i.stack.imgur.com/zVrrf.jpg

Get lighter and darker color variations for a given UIColor

I recently switched to es6 and started using arrow functions all over my code.
While refactoring I came across below code

    data.map(function(d) {
       return {id: d.id, selected: bool};
    });

I changed above code to this -

    data.map((d) =&gt; {id: d.id, selected: bool});

But I was getting error from above code. I don&#39;t know what is wrong here?
I know that If there is no block of code then there is implicit return provided by arrow function.

But don&#39;t know how to return empty object or anonymous object with some properties initialized ?

**Edit:**

What is wrong if I do it in this way? Just for curiosity sake.

    data.map((d) =&gt; new {id: d.id, selected: bool});



How to return anonymous object from one liner arrow function in javascript?

Whats is the difference between `Array&lt;string&gt;` and `string[]`? 

    var jobs: Array&lt;string&gt; = [&#39;IBM&#39;, &#39;Microsoft&#39;, &#39;Google&#39;];
    var jobs: string[]      = [&#39;Apple&#39;, &#39;Dell&#39;, &#39;HP&#39;];



What is the difference Array&lt;string&gt; and string[]?

Whats is the difference between <code>Array&#x3C;string></code> and <code>string[]</code>?
<pre><code class="hljs language-less">var jobs: Array&#x3C;string> = ['IBM', 'Microsoft', 'Google'];
var jobs: string[] = ['Apple', 'Dell', 'HP'];
</code></pre>

I have a component which calls a service to fetch data from a RESTful endpoint. This service needs to be given a callback function to execute after fetching said data.

The issue is when I try use the callback function to append the data to the existing data in a component&#39;s variable, I get a `EXCEPTION: TypeError: Cannot read property &#39;messages&#39; of undefined`. Why is `this` undefined?

TypeScript version: Version 1.8.10

Controller code:

    import {Component} from &#39;@angular/core&#39;
    import {ApiService} from &#39;...&#39;
    
    @Component({
        ...
    })
    export class MainComponent {
        
        private messages: Array&lt;any&gt;;
    
        constructor(private apiService: ApiService){}
        
        getMessages(){
            this.apiService.getMessages(gotMessages);
        }
    
        gotMessages(messagesFromApi){
            messagesFromApi.forEach((m) =&gt; {
                this.messages.push(m) // EXCEPTION: TypeError: Cannot read property &#39;messages&#39; of undefined
            })
        }
    }



Angular2 component&#39;s &quot;this&quot; is undefined when executing callback function

I have an object where all the keys are string, some of the values are string and the rest are objects in this form:

    var object = {
        &quot;fixedKey1&quot;: &quot;something1&quot;,
        &quot;fixedKey2&quot;: &quot;something2&quot;,
        &quot;unknownKey1&quot;: { &#39;param1&#39;: [1,2,3], &#39;param2&#39;: &quot;some2&quot;, &#39;param3&#39;: &#39;some3&#39;},
        &quot;unknownKey2&quot;: { &#39;param1&#39;: [1,2,3], &#39;param2&#39;: &quot;some2&quot;, &#39;param3&#39;: &#39;some3&#39;},
        &quot;unknownKey3&quot;: { &#39;param1&#39;: [1,2,3], &#39;param2&#39;: &quot;some2&quot;, &#39;param3&#39;: &#39;some3&#39;},
        ...
        ...
    };

In this object `fixedKey1` and `fixedKey2` are the known keys which will be there in that object. `unknownKey` - value pair can vary from 1-n.

I tried defining the interface of the object as:

    interface IfcObject {
        [keys: string]: {
            param1: number[];
            param2: string; 
            param3: string;
      }
    }

But this throws the following error:

&gt; Variable of type number is not assignable of type object

Which I found out that it is not able to assign this interface to &quot;fixedKey - value&quot; pair.  

So, how can I do the type checking of this kind of variables?


Typescript interface for objects with some known and some unknown property names

I receive the warning...

&gt; Experimental support for decorators is a feature that is subject to change in a future release. Set the &#39;experimentalDecorators&#39; option `to remove this warning.

... even though my compilerOptions in tsconfig.json have the following settings:


    &quot;emitDecoratorMetadata&quot;: true,
    &quot;experimentalDecorators&quot;: true,


What is weird is that some random classes that use decorators do not show that warning but the rest in the same project do.

What could cause such behavior in the TypeScript compiler?

Experimental decorators warning in TypeScript compilation

I&#39;m looking for a way to use npm scripts to run `tsc --watch &amp;&amp; nodemon --watch` at the same time. I can run these commands independently, but when I want run both of them, only the first one is executed.
eg:

    &quot;scripts&quot;: {    
        &quot;runDeb&quot;: &quot;set NODE_ENV=development&amp;&amp; tsc --watch &amp;&amp; nodemon --watch&quot;
      }

`tsc --watch` is executed but `nodemon` is never called, and vice versa.

Is there a way to use npm scripts to run tsc -watch &amp;&amp; nodemon --watch?

I dont know how to extract value from Observable to be returned by function in which Observable is present. I need just a value from it to be returned, nothing else.

Current version which works

 	function getValueFromObservable() {
    	this.store.subscribe(
	    	(data:any) =&gt; {
		    	console.log(data)
    		}
    	)
    }
    getValueFromObservable()

I need this to work, function to return value, and then:

 	function getValueFromObservable() {
    	this.store.subscribe(
	    	(data:any) =&gt; {
		    	return data
    		}
    	)
    }
    console.log(getValueFromObservable())

What am I doing wrong here?

Content Type	Original Author	Original Content on Stackoverflow
Question	Sajith Mantharath	View Question on Stackoverflow
Solution 1 - Typescript	Nitzan Tomer	View Answer on Stackoverflow

What is the difference Array<string> and string[]?

Typescript Problem Overview

Typescript Solutions

Solution 1 - Typescript

How to return anonymous object from one liner arrow function in javascript?

Get lighter and darker color variations for a given UIColor

Attributions