how to check value of checkbox in jquery code example

Example 1: jquery checkbox checked value

if ($('#check_id').is(":checked"))
{
  // it is checked
}

Example 2: check a checkbox jquery

$('#grepperRocks').prop('checked', true);

Example 3: get the value of a checkbox jquery

$("input[type='checkbox']").val();
$('#check_id').val();