const array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
  

    function binarySearch(array, target) {
      let left = 0;
      let right = array.length - 1;

      while (left <= right) {
        let mid = Math.floor((left + right) / 2);

        if (array[mid] === target) {
          return mid;
        }

        if (array[mid] < target) {
          left = mid + 1;
        } else {
          right = mid - 1;
        }
      }

      return -1;
    }
  

    binarySearch(array, 4);