Javascript Filter on Variable Set

<script type="text/javascript">
    function check() {
        var elements = document.getElementsByName("quantity");
        var qtycheck = document.getElementById("qtycheck").value;

        for (var i=0; i<elements.length; i++) {
            var nmbr = elements[i].value;
            if (nmbr > <?php echo $maxqtyorder; ?>){
                alert("You've selected more treats than your package allows.");
                return false;
            }
            else if (nmbr > qtycheck){
                alert("You've selected more treats than your package allows.");
                return false;
            }
        }
        return true;
    }
</script>

Code (markup):

The 2nd line:

var elements = document.getElementsByName("quantity");

Code (markup):

I want to get all the elements by name of quantity but exclude the ones that have an ID of quantity2442 and quantity2443.

Is there a way to do this when setting the variable?

 

Generally speaking no, and any processing to check them before the loop would take as long as inside the loop -- I'd suggest using a switch for the ID inside the loop that does a 'continue', skipping the rest of the code in the loop and proceeding to the next item.

Some advice: if both test cases do the same thing, don't make them separate test cases -- outputting the entire script in PHP means it can't be cached, have PHP assign that value to a global or something... and if you have a bunch of VAR in a row you can make them a comma delimited list, so you don't have to say "VAR" every blasted time.

function check() {
	var
		elements = document.getElementsByName("quantity"),
		qtycheck = document.getElementById("qtycheck").value,
		i, value;

	for (i = 0; i < elements.length; i++) {
		switch (elements[i].id) {
			case 'quantity2442':
			case 'quantity2443':
				continue;
		}
		value = elements[i].value;
		if (
			(value > <?php echo $maxqtyorder; ?>) ||
			(value > qtycheck)
		) {
			alert("You've selected more treats than your package allows.");
			return false;
		}
	}
	return true;
}

Code (markup):

another approach would be to put the ones you don't want in an array and use Array.indexOf, but you'd want to include a shim since older browsers (IE8/earlier) don't have that method.

if (!Array.indexOf) Array.prototype.indexOf = function (v, s) {
	if (this == null || typeof this == 'undefined') throw new TypeError(
		'Illegal operation on undefined variable'
	);
	for (var t = s || 0; t < this.length; t++) if (this[t] == v) return t;
	return -1;
};

function check() {
	var
		elements = document.getElementsByName('quantity'),
		qtycheck = document.getElementById('qtycheck').value,
		blackList = ['quantity2442', 'quantity2443'],
		i, value;

	for (i = 0; i < elements.length; i++) {
		if (blackList.indexOf(elements[i].id) >= 0) continue;
		value = elements[i].value;
		if (
			(value > <?php echo $maxqtyorder; ?>) ||
			(value > qtycheck)
		) {
			alert("You've selected more treats than your package allows.");
			return false;
		}
	}
	return true;
}

Code (markup):

The blackList is probably easier if you have a lot of them, especially if you're going to want PHP to set them using a global or value pass so the script itself can be cached across pages.

 

Exactly what I was looking for thanks!