Question

how to trigger a event in jquery when the value of a textarea is changing without losing focus form textarea.

Answer 1

You can use the keyup event to get the value as it’s entered, like this:

$("textarea").keyup(function() {
  var newVal = $(this).val();
});

Or, to be a bit safer:

$("textarea").bind("keyup paste change", function() {
  var newVal = $(this).val();
});

Unlike only using change this will get the value as it updates, instead of when the <textarea> loses focus.