Count of “Defined” Array Elements

Question

Given following array:

var arr = [undefined, undefined, 2, 5, undefined, undefined];

I\'d like to get the count of elements which are

Answer 1

Loop and count in all browsers:

var cnt = 0;
for (var i = 0; i < arr.length; i++) {
    if (arr[i] !== undefined) {
        ++cnt;
    }
}

In modern browsers:

var cnt = 0;
arr.foreach(function(val) {
    if (val !== undefined) { ++cnt; }
})