Question

I want to get all the IDs that start with blblblb_ and run a separate JS function that I made. Here is what I have, it is only getting the first ID:

$(window).scroll(function() {
  var test = $('div[id^="blblblb_"]').attr('id');
  foo(test);
});

Any ideas what I’m doing wrong?

Answer 1

The problem is that attr gives you the id of the first element in collection and you’re only calling foo once anyway.

Use each to execute a function for all elements of a jquery collection :

$(window).scroll(function() {
    $('div[id^="blblblb_"]').each(function(){
        foo(this.id);
    });
});

---

Based on your comment, if you have a growing collection of objects having this kind of id and wanting to be sure foo is only called once for each id, you might do this :

var done = {};
$(window).scroll(function() {
    $('div[id^="blblblb_"]').each(function(){
         if (!done[id]) {
             foo(this.id);
             done[id] = 1;
         }
    });
});

But I’m doubtful about the use case…