Remove duplicates from a sorted array.

/**
 * @param {number[]} nums
 * @return {number}
 */
var removeDuplicates = nums => {
  for (let i = 0; i < nums.length - 1; ) {
    if (nums[i] === nums[i + 1]) {
      nums.splice(i, 1);
      continue;
    }
    i++;
  }
  return nums.length;
};