not empty in jquery code example

Example 1: jquery if null or empty

if (jQuery('#something').val().length != ''){}
or
if (jQuery('#something').val().length != 0){}

Example 2: check fro text input jquery

$('#apply-form input').blur(function()
{
    if( !$(this).val() ) {
          $(this).parents('p').addClass('warning');
    }
});

Example 3: .empty() in jquery

// Remove all child nodes of the set of matched elements from the DOM
// This method does not accept any arguments.
$("div.parent").empty();

$("button").click(function(){
   $("div").empty();
});