default checkbox to checked jquery code example

Example 1: jquery set checkbox checked

//jQuery 1.6+ use
$('.checkbox').prop('checked', true);
//jQuery 1.5.x and below use
$('.checkbox').attr('checked', true);

Example 2: jquery prop checked

// Check #x
$( "#x" ).prop( "checked", true );
 
// Uncheck #x
$( "#x" ).prop( "checked", false );