$(this).addClass jquary code example
Example 1: jquery add class
if ($( "#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;
});