if control has class jquery code example

Example 1: jquery hasclass

if ($( "#foo" ).hasClass('className')) {
	$( "#foo" ).removeClass( 'className');
} else {
  $( "#foo" ).addClass( 'className');
}

Example 2: how to add class on the base of has class in jquery

$( "ul li" ).addClass(function( index ) {
  return "item-" + index;
});