<script>
    var arr = [12, 34, 37, 56, 67, 78, 89, 90, 99]
    function search(arr, key) {
      let low = 0;
      let high = arr.length - 1;
      while (low <= high) {
        let mid = parseInt((high + low) / 2);
        if (arr[mid] == key) {
          return mid;
        } else if (arr[mid] > key) {
          high = mid - 1;
        } else {
          low = mid + 1;
        }
      }
      return -1;
    }
    console.log(search(arr, 34));

  </script>