对未排序数组的二进制搜索的时间复杂度。

I am stuck up with two time complexities. To do a binary search with sorted array is O(logN). So to search an unsorted array we have to sort it first so that becomes O(NlogN). So then we can perform binary search which gives the complexity as O(N) but I have read that it could be O(NlogN). Which is correct?I am stuck up with two time complexities. To do