javascript - jquery split() and indexOf results in "Object doesn't support this property or method"

Question

I have the following code:

var selected = $('#hiddenField').val().split(",");
...
if (selected.indexOf(id) > 0) {
   ... set value ...
}

I'm dynamically creating a CheckBoxList, and trying to remember the state of the checkboxes by putting the selected IDs into the hidden field.

I get an error stating that "Object doesn't support this property or method". My assumption is that selected is an array, which should support indexOf. Is that incorrect?

Answer 1

There's an jQuery method to overcome the lack of indexOf(), you can use .inArray() instead:

var selected = $('#hiddenField').val().split(",");
if ($.inArray(id, selected) > -1) {
   ... set value ...
}

jQuery.inArray() exists for just this reason...if you're including jQuery already, no need to write the function again. Note: This actually returns a number, like indexOf() would.