Remove key from JSON array

var jsonArr=[{
                XXX: "2",       
                ZZZ: "4"
             },
             {
                XXX: "5",       
                ZZZ: "7"
             },
             {
                XXX: "1",       
                ZZZ: "3"
             }];
             
for(var i = 0; i < jsonArr.length; i++) {
    delete jsonArry[i]['YYY'];
}