javascript - 每 5 个循环计数一次

Question

我在这里遇到了这个问题:

Write a function named sumEvery5th that accepts a non-negative integer n and returns the sum of the integers divisible by 5 from 1 to n, including n itself. Use a for loop.

这是我目前所拥有的:

var sumEvery5th = function(n){

    let sum = 0;
    for(let i = 1; n % 5 == 0; i++){
        sum+ i
    };
    return sum;
}

我觉得我真的很亲近。提前感谢您的帮助。

Answer 1

你可以从 5 开始你的循环，因为 1, 2... 不能被 5 整除。而不是 i++，你可以直接用 5 乘以 5 , 直到 i 大于 n:

var sumEvery5th = function(n) {
  let sum = 0;
  for (let i = 5; i <= n; i += 5) {
    sum += i;
  };
  return sum;
}

console.log(sumEvery5th(10)); // 5 + 10 = 15
console.log(sumEvery5th(18)); // 5 + 10 + 15 = 30