704. Binary Search

public int search(int[] nums, int target) {
  int left = 0;
  int right = nums.length - 1;

  while (left <= right) {
    int mid = left + (right - left) / 2;

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

• line no. 5: <= because we are taking right as nums.length - 1

• line no. 6: left + (right - left) / 2 instead of (left + right) / 2 for avoiding overflow.

• line no. 11: mid + 1 as mid has been checked already.

• line no. 13: mid - 1 as mid has been checked already.