BinarySearch.js

//Binary search in while loop
var search = function(nums, target) {
    let low = 0;
    let high = nums.length ;
    let mid;

    if(high === low + 1){
        if (target == nums[low]){
            return low
        }else {
            return -1
        }
    }

    while(low <= high){
        mid = (low + high) / 2;
        if(target === nums[mid]){
            return mid;
        }
        if(target > nums[mid]){
            low = mid + 1;
        }else {
            high = mid - 1;
        }
    }

    return -1;
};

//Binary search in recursion
function recersivSearch(low, heigh, key) {
    if (low === heigh) {
        if (arr[0]=== key) return 0;
        else return -1;
    }
    mid = (low + heigh ) / 2;
    if (arr[mid] === key) {
        return mid
    }
    if (arr[mid] > key) {
        return recersivSearch(mid + 1, heigh, key)
    }else {
        return recersivSearch(low, mid - 1, key);
    }
}