text: /**
   * @param {number[]} nums1
   * @param {number[]} nums2
   * @return {number[]}
   */
  var intersection = function(nums1, nums2) {
    const num1set = new Set(nums1);
    const num2set = new Set(nums2);
    const res = [];
  
    num1set.forEach(e => num2set.has(e) ? res.push(e) : null);
  
    return res;
  };