Take the last two numbers from an array, sum them, and append to the end of the array.

appendSum.md

Take the last two numbers from an array, sum them, and append to the end of the array.

function appendSum(nums) {
    nums.push(nums[nums.length - 1] + nums[nums.length - 2]); 
    nums.push(nums[nums.length - 1] + nums[nums.length - 2]); 
    nums.push(nums[nums.length - 1] + nums[nums.length - 2]);
    return nums
}
console.log(appendSum([1, 1, 2]))

A less elegant solution, but a solution nonetheless

function appendSum(nums) {
  let newList = nums;
  for (let i = 0; i < 3; i++) {
  let num1 = nums[nums.length - 1];
  let num2 = nums[nums.length - 2];
  newList.push(num1 + num2);
  }
   return newList;
 }
 console.log(appendSum([1, 1, 2]));