Remove empty elements from an array in Javascript

Question

How do I remove empty elements from an array in JavaScript?

Is there a straightforward way, or do I need to loop through it and remove them manually?

Answer 1

Another way to do it is to take advantage of the length property of the array : pack the non-null items on the 'left' of the array, then reduce the length. It is an in-place algorithm -does not allocates memory, too bad for the garbage collector-, and it has very good best/average/worst case behaviour.

This solution, compared to others here, is between 2 to 50 times faster on Chrome, and 5 to 50 times faster on Firefox, as you might see here : http://jsperf.com/remove-null-items-from-array

The code below adds the non-enumerable 'removeNull' method to the Array, which returns 'this' for daisy-chaining :

var removeNull = function() {
    var nullCount = 0           ;
    var length    = this.length ;
    for (var i=0, len=this.length; i