Unchecked checkbox returning null value

Question

I have a set of checkboxes which when checked they pass the value as 1, otherwise they pass the value as 0. However, instead of sending the value of the unchecked checkboxe

Answer 1

CHANGE YOUR SCRIPT LIKE THIS. HOPE IT HELPS.

$(document).ready(function(){
    $('#cb1, #cb2, #cb3, #cb4').click(function(){
        $(this).val(this.checked ? 1 : 0);
    });
});