Putting it together

Putting it together

• Real programs combine variables, loops, functions, arrays and objects.
• A for...of loop reads each item of an array directly — no index needed.

function total(nums) {
  let t = 0;
  for (const n of nums) {
    t = t + n;
  }
  return t;
}
console.log(total([4, 8, 6]));   // → 18

Searching and counting

• Loop through the array, and keep a counter (or a flag) as you go.

function countAbove(nums, limit) {
  let count = 0;
  for (const n of nums) {
    if (n > limit) {
      count++;
    }
  }
  return count;
}
console.log(countAbove([3, 7, 2, 8], 4));   // → 2

Common mistakes

• Build in small steps and use console.log to check as you go.
• Set a running total to 0 (or a list to []) before the loop, not inside it, or it starts again every time round.

Now you try

• Write each function using a loop.
• Press Check answer to test it.