How to prevent user to enter text in textarea after reaching max character limit

The keyup event fires after the default behaviour (populating text area) has occurred.

It’s better to use the keypress event, and filter non-printable characters.

Demo: http://jsfiddle.net/3uhNP/1/ (with max length 4)

jQuery(document).ready(function($) {
    var max = 400;
    $('textarea.max').keypress(function(e) {
        if (e.which < 0x20) {
            // e.which < 0x20, then it's not a printable character
            // e.which === 0 - Not a character
            return;     // Do nothing
        }
        if (this.value.length == max) {
            e.preventDefault();
        } else if (this.value.length > max) {
            // Maximum exceeded
            this.value = this.value.substring(0, max);
        }
    });
}); //end if ready(fn)