javascript递归查找数组元素为什么没有返回true?

Question

         var arr2=["a","b",33,["cc","dd"],[['eee',22],["fff",555],["zz",88]],["dff"]];             function exist(arr,exi){                 for (var key = 0; key < arr.length; key++) {                     if(Array.isArray(arr[key])){                         exist(arr[key],exi);                         continue;                     }                     console.log(arr[key],exi);                     if(arr[key]==exi){                         console.log("-------------");                         return true;                      }                 }             }             console.log(exist(arr2,22));                        console.log("-------------");都有输出；                        可是却不返回true是为什么?