0027. Remove Element

class Solution {
    public int removeElement(int[] nums, int val) {
        int res = 0;
        for (int i = 0, j = 0; j < nums.length; j++) {
            if (nums[j] != val) {
                res++;
                nums[i++] = nums[j];
            }
        }
        return res;
    }
}