Answers for "jquery checkbox checked value get"

jQuery is checkbox checked

//using plane javascript 
if(document.getElementById('on_or_off_checkbox').checked) {
    //I am checked
} 

//using jQuery
if($('#on_or_off_checkbox').is(':checked')){
    //I am checked
}

how to get checkbox value in jquery

var grenval = $('.green').val();
 $('.showCheckedValue').text(redval+'&'+grenval );