In JavaScript, what's the difference between myArray.length = 0 vs myArray = new Array()?

Question

Regarding JavaScript, when clearing an array, I've found two methods:

myArray.length = 0;

vs

myArray = new Array()

I would guess myArray.length = 0; keeps the reference while myArray = newArray() creates a new reference making previous references void.

What's the difference (if any) between the two methods?

Answer 1

You are correct this time. new Array() creates a new instance of array and assign it to myArray. myArray.length = 0 empties an old array while myArray still points to the old array.

Btw, it is better to use [] notation than new Array().

I personally always try to use myArray.length = 0; since it actually empties the content of the array.

Answer 2

myArray.length = 0; // Signifies empty array
[1,2,3] // Length of this array is 3

So basically, an array with content is overwritten with an empty array.

You can also use this:

myarray = []; //More simple and elegant!!!

Performance wise: [] is faster than new Array();

As juno already said: new Array() creates a new instance of the array (this array will be of the size mentioned in arguments) and assigns it to myArray.