Question

I have a number within a span element that changes often. I want to be able to detect any changes in this number and store that number in a variable.

so far I have tried this:

var x = $('#mynum').text();

This code however doesn’t detect any changes – it only gets the value when the page first loads.

I have also tried this:

$('#mynum').bind('change',function(){

alert('wahoo!');   });

However I cannot get it to even make the alert.

What would be the best way to detect the changes and store the number in a variable whenever it does change?

Answer 1

Change event only happens from the browser on the blurring of form fields. If you’re changing the value of a span from your script, you need to $('#mynum').trigger('change');. Then your bind will work, assuming the element #mynum was in the DOM when the bind was set. If not, bind to a consistent parent element and delegate it with on:

$('#myParentNode').on('change','#mynum', function() {
    alert('wahooo!');
});