如何在排序后的数组中找到某个值？

这是一个排序数组：

[15, 24, 30, 48, 49, 64, 86, 90, 100, 121, 130]

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

function binarySearch(arr, x) {   // left index of the current interval   let l = 0;     // right index of the current interval   let r = arr.length - 1;     // middle index of the current interval   let mid;     while (r >= l) {     mid = l + Math.floor((r - l) / 2);       // If the element is present at the middle     // itself     if (arr[mid] == x) {       return mid;     }       // If element is smaller than mid, then     // it can only be present in left subarray     if (arr[mid] > x) {       r = mid - 1;     }       // Else the element can only be present     // in right subarray     if (arr[mid] < x) {       l = mid + 1;     }   }     // We reach here when element is not   // present in array   return -1; }