is checked checkbox jquery

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

//using jQuery
if($('#on_or_off_checkbox').is(':checked')){
    //I am checked
}$(your_checkbox).is(':checked');if($("#isAgeSelected").is(':checked'))
    $("#txtAge").show();  // checked
else
    $("#txtAge").hide();  // unchecked
var checked = '0';  if($('#checkbox').prop('checked')){ checked = '1'; }$('#' + id).is(":checked")