JavaScript

求n个数字的累加和

1. 递归实现

    function getSum(x) {
      if (x == 1) {
        return 1;
      }
      return x + getSum(x - 1);
    }

    var result = getSum(100);
    console.log(result);

求一个数字的每个位数上的和 :如:23--->5

1. 递归实现

    function getnumberSum(x) {
      if (x < 10) {
        return x;
      }
      return parseInt(x % 10 + getnumberSum(x / 10));
    }
    console.log(getnumberSum(123));