What is the correct way to write a JavaScript array?

Answer 1

The most common and shortest way to write a JavaScript array is:

var myArray=[1,2,3];

You can also use:

var myArray=new Array(1,2,3);

Or:

var myArray=new Array();

myArray[0]=1;

myArray[1]=2;

myArray[2]=3;

All of these produce the same array containing the elements 1, 2, and 3.

Answer 2

An array in javascript can be created in multiple ways that all creates an instance of the javascript built-in Array object, the most common being this:

var foo = []; //foo now is an array

Other ways are:

var foo = new Array();

or

var foo = Object.create(Array.prototype);

But i dont know of any cases where this would be necessary, and the short way where just assigning empty square braces in a variable declaration is thought of to be best considering it alost always is simpler.

You can also assign indexes to an array at the same time as you create the array.

var foo = [1, 2];

or

var foo = new Array(1, 2);

Note that even though you can use string literals as array indexes, arrays in javascript are thought to only use numerical indexes. For string indexing one should use native objects, that in fact works in a similar way:

var foo = {};

var foo = new Object();

or

var foo = Object.create(Object.prototype);

For both arrays and object indexes (or properties for objects) kan be created or assigned to as this:

foo[1] = null;

foo[2] = 'bar';

foo[3] = 123;

objects:

foo['bar'] = null;

foo['baz'] = 'qux';

You can assign to a array index og object property whatever you can assign to a normal variable.