关于javascript:二分查找

var search = function(nums, target) {
    let start = 0
    let end = nums.length - 1
    while(start <= end) {let mid = Math.floor((start + end)/2)
        if (target < nums[mid]) {end = mid - 1} else if (target > nums[mid]) {start = mid + 1} else {return mid}
    }
    return -1
};