Design a function that removes all occurrences of a given integer from an array and returns the new length of the array. You must modify the input array in-place with O(1) extra memory.

Input: nums = [3,2,2,3], val = 3
Output: 2, nums = [2,2]
Explanation: Your function should return length = 2, with the first two elements of nums being 2.

Requirements:

• The function signature should be int removeElement(int[] nums, int val).
• Discuss the approach you would take to solve this problem, considering the constraints.

Follow-up Discussion:

• How does your solution handle cases with multiple occurrences of the val?
• What are the potential pitfalls in your approach, and how can you avoid them?