how to get value from checkbox in jquery code example

Example 1: get value of selected checkbox jquery

$('#checkbox_id:checked').val();
//if checkbox is selected than gets its value

Example 2: jquery checkbox checked value

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

Example 3: get the value of a checkbox jquery

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

Example 4: get value of checked checkboxes jquery

var values = $('input[name=grepperRocks]:checked')
               .map(() => { return this.value }).get();