How to fire JQuery change event when input value changed programmatically?

Solution 1:

change event only fires when the user types into the input and then loses focus.

You need to trigger the event manually using change() or trigger('change')

$("input").change(function() {
  console.log("Input text changed!");
});
$("input").val("A").change();

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<input type='text' />

Solution 2:

The event handler .change() behaves like a form submission - basically when the value changes on submit the console will log. In order to behave on text input you would want to use input, like below:

$("input").on('input', function(){
    console.log("Input text changed!");
});
$("input").val("A");

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type='text' />

Solution 3:

What you need to do is trigger the change event after you've set the text. So you may create a function to do that so you won't have to repeat it every time you need to update the text, like this:

function changeTextProgrammatically(value) {
    $("input").val( value );
    $("input").trigger( 'change' ); // Triggers the change event
}

changeTextProgrammatically( "A" );

I've updated the fiddle,