BinarySearch.js

let binarySearch = function (array, valueSearch) {
  let start = 0;
  let end = array.length - 1;
  
  return function search(start, end) {
    let mid = Math.round((start + end) / 2);
    let length = end - start;
  
    if (length < 0) return -1;

    if (array[mid] === valueSearch) {
      return mid;
    } else if (array[mid] > valueSearch) {
      return search(start, mid - 1);
    } else if (array[mid] < valueSearch) {
      return search(mid + 1, end);
    }
  }(start, end);
}