Remove Duplicates from Sorted Array - I

Problem Statement #
Given an array of sorted numbers, remove all duplicates from it. You should not use any extra space; after removing the duplicates in-place return the new length of the array.

Example 1:

Input: [2, 3, 3, 3, 6, 9, 9]
Output: 4
Explanation: The first four elements after removing the duplicates will be [2, 3, 6, 9].

/**
 * @param {number[]} nums
 * @return {number}
 */
var removeDuplicates = function(nums) {

    let resPointer = 1;

    for (let right = 1; right < nums.length; right ++) {
        if (nums[resPointer - 1] !== nums[right]) {
            nums[resPointer] = nums[right];
            resPointer++;
        }
    }

    return resPointer;
};