How to get change event after js changes a value without modifing existing code

Question

an input field changes its value via jquery (not by a human action), like this: $("#code").val(9); . How can I intercept the change event (or similar) without changing or add new lines to code that changes its value.

Answer 1

Programmatically setting value does not trigger any user events so you must trigger one yourself after the new value is set.

I used a change event but you could use others like the "input" event

 $("#code").on('change', function(){ console.log('changed value =', this.value); }); $("#code").val(9).change(); // or // $("#code").val(9).trigger('change');

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <input id="code"/>