if document has class jquery code example

Example 1: jquery hasclass

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

Example 2: jquery hasclass

$( "#mydiv" ).hasClass( "foo" )

Example 3: if a class exists jquery

if ($(".mydivclass").length){
    // Do something if class exists
} else {
    // Do something if class does not exist
}