Javascript array copying, concat vs slice, which one is better? [closed]

Question

there are two different ways to copy a array, using Array.concat or Array.slice,

for example:

var a = [1, 2, 3],

    c1 = [].concat(a),

    c2 = a.slice(0);

which way is better?

Answer 1

For clarity, you should use the method that is the documented method of taking a copy of an array (or portion thereof):

var c2 = a.slice(0);

On any decent browser the performance difference will be negligible, so clarity should be the deciding factor.

Answer 2

In terms of performance, the difference between the two options are minimal, according to a jsperf.com test.