js递归遍历key

 var obj = {
     first: "1",
     second: {
         name: "abc",
         mykey: "2",
         third: {
             age: "30",
             mykey: "3"
         }
     },
     forth: "4",
     mykey: "5"
 };

 console.log(getMykey(obj, []));

 function getMykey(obj, mykeyValues) {
     //没有则跳出
     if (!obj["mykey"]) {
         return mykeyValues;
     } else {
         //有就放入
         mykeyValues.push(obj["mykey"]);
         //再次递归
         var keys = Object.keys(obj);
         keys.forEach(function(i) {
             getMykey(obj[i], mykeyValues);
         });
     }
     return mykeyValues;
 }