jquery not grabbing elements code example

Example 1: how to find a name of class from page in jquery

$("input[type='submit']").click(function() {
    if ($(".Mandatory").length > 0) {
        // Do some code here
    }
});

Example 2: how to find a name of class from page in jquery

if ($('.Mandatory').length > 0) {
  //do your thing
}