src code

instance method Array#compact

Array#compact() → Array

Returns a copy of the array without any null or undefined values.

Example
var orig = [undefined, 'A', undefined, 'B', null, 'C'];
var copy = orig.compact();
// orig -> [undefined, 'A', undefined, 'B', null, 'C'];
// copy -> ['A', 'B', 'C'];