Java之递归求和的两种简单方法(推荐)

package com.smbea.demo;  public class Student {   private int sum = 0;       /**    * 递归求和    * @param num    */  public void sum(int num) {     this.sum += num--;          if(0 < num){       sum(num);     } else {       System.out.println("sum = " + sum);     }   }    }

package com.smbea.demo;  public class Test {    public static void main(String[] args) {     Teacher teacher = new Teacher();     teacher.sum();   }    public static int sum(int num){     if(1 == num){       return 1;     } else {       return num + sum(num - 1);     }   }; }