Add up the numbers from 1 to n

The challenge

Write sumTo(n) that returns 1 + 2 + 3 + … + n. For 0 or less, return 0.

Try it

Write your answer below, then press Check my answer. Your code runs right here in your browser, and the tests tell you what works.

What the tests check

• sumTo(3) gives 6
• sumTo(100) gives 5050
• sumTo(1) gives 1
• sumTo(0) gives 0

Hints

Stuck? Open one hint at a time. Try again after each one.

A solution

There’s always more than one right way. Read it, make sure you understand it, then try writing it yourself without looking.

function sumTo(n) {
  let total = 0;
  for (let i = 1; i <= n; i++) {
    total += i;
  }
  return total;
}

Learn what you need

This exercise uses what Grade 5: Loops: Doing Things Over and Over teaches. Read those notes first if any of it is new.