js ??? ???? ??? ?? ??? ?????
4
0
0
Array.prototype.itemOf = ??(??) {
for (var i = 0; i < this.length; i++)
{
}
return -1;
};
arr[index], ??? ??? ?? ??? ?? ??? ?? ???? ? ????. ?? ??? ?? ?????
![[? ?????] Node.js ?? ??](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
