Question

I am new to JavaScript. From some tutorials I know in javascript there are two ways to declare the array.
One is like this:

var test = new Array("apple","pine");

or

test = new Array("apple","pine");

Two are like this,

var test=["apple","pine"];

but when i use this way to declare it:

test=Array("apple","pine");

It is still ok. why?

Answer 1

In Javascript, you may (and should) declare a variable using the var keyword, but it’s not required. So any variable can be declared like this:

var a = 'abc';

or

a = 'abc';

But the first one (with var) should always be used when you’re creating a new variable. Otherwise, you might be overwriting an already existing variable with the same name. An array is also a variable, so it too can be declared either with or without the var keyword. Then there are two ways to declare an array, and both do exactly the same thing:

var a = ['a', 'b', 'c'];

does the same as:

var a = new Array('a', 'b', 'c');

and the new keyword, in this case, is not required – as per the javascript specification. But it’s usually used to indicate that you’re creating a new instance of an object.