How do you sort alphabetical without case sensitive

Question

How do i make this alpha sort not case sensitive? I understand that you should use to toLowerCase but I don't know how.

sort_alpha: function(a,b) {
    if (a[0]==b[0]) return 0;
    if (a[0]<b[0]) return -1;
    return 1;
}

Answer 1

You need to turn a and b into lower case

var lower_a = a.toLowerCase();
var lower_b = b.toLowerCase();