OverLoad怎么用

 1 package practice3;
 2 
 3 
 4 public class TryOverLoad {
 5     public static void main(String[] args) {
 6         System.out.println(add(10,15));//调用第一个add
 7         System.out.println(add(10,15,20));//调用第二个add
 8         System.out.println(add(10.5,15));//调用第三个add
 9     }
10     public static int add(int n1,int n2) {
11         int sum=n1+n2;
12         return sum;
13     }
14     public static int add(int n1,int n2,int n3) {
15         int sum=n1+n2+n3;
16         return sum;
17     }
18     public static double add(double n1,int n2) {
19         double sum=n1+n2;
20         return sum;
21     }
22     
23 }