In Javascript, why is

var myArray = new Array(3);

different from:

var otherArray = [null, null, null];

?

Obs: (myArray == otherArray) returns false.

And also, how can I get a variable like otherArray, which is an array full of 'nulls`, but with whatever size i'd like?

Obs

[undefined, undefined, undefined] 

is also not equal to myArray.