Keyup event in jQuery Count number of characters in string Javascript

Keyup event when a user releases a key on the keyboard.
This is shorthand for the .on( "keyup", handler) and .trigger("keyup") methods.

The following example counts the number of characters that we are writing in a form.

val(). Gets the value of the selected item.
html(). Allows you to write html content inside the selected element.
length. Gets the width, according to characters, of the string to which it refers.

<input id="wr" type="text">
<div id="len"></div>
<!--Script jQuery-->
<script>
$("#wr").keyup(function() {
  var num_chars = $(this).val().length;
  $('#len').html('Number of characters: '+num_chars);
});
</script>
<!--JQuery Library-->
<script src="https://code.jquery.com/jquery-3.6.3.min.js"></script>