Sort an array so that null values always come last

Question

I need to sort an array of strings, but I need it so that null is always last. For example, the array:

var arr = [a, b, null, d, null]

When

Answer 1

like this, note: this will only push the null's to the back

var arr = ["a", null, "b"];
var arrSor = [];
arr.forEach(function (el) {

    if (el === null) {
        arrSor.push(el);
    } else {
        arrSor.unshift(el);
    }
});