Character count using jQuery

Question

How can I count the number of characters in a textbox using jQuery?

$("#id").val().length < 3

just counts upto 3 character spaces but not the number of characters.

Answer 1

Improved version 

$('#field').keyup(function () {
  var max = 500;
  var len = $(this).val().length;
  if (len >= max) {
    $('#charNum').text(' you have reached the limit');
  } else {
    var char = max - len;
    $('#charNum').text(char + ' characters left');
  }
});