JavaOOP 递归

package cn.hello.test6单例;public class Test递归 {public static void main(String[] args) {System.out.println(sum(100));}    public static int sum(int num)    {    if (num==1) {return 1; //直接返回1}    // 100,99,98,97,96,    return num+sum(num-1);    }}