Java学习泛型之可变参数

可变参数

可变参数又称参数个数可变，用作方法的形参出现，那么方法参数个数就是可变的了

格式：修饰符 返回值类型 方法名(数据类型...变量名){}

范例：public static int sum(int...a){}

package com.itheima_99;
/*
  测试类
 */
public class ArgsDemo01 {
    public static void main(String[] args) {
        System.out.println(sum(10,20));
        System.out.println(sum(10,20,30));
        System.out.println(sum(10,20,30,40));
        System.out.println(sum(10,20,30,40,50));
        System.out.println(sum(10,20,30,40,50,60));
        System.out.println(sum(10,20,30,40,50,60,70));
        System.out.println(sum(10,20,30,40,50,60,70,80));
        System.out.println(sum(10,20,30,40,50,60,70,80,90));
    }

//    public static int sum(int b,int...a){
//        return 0;
//
//    }

    public static int sum(int...a){
//        System.out.println(a);
//        return 0;
        int sum = 0;
        for (int i:a){
            sum += i;
        }
        return sum;
    }

//    public static int sum(int a,int b){
//        return a + b;
//    }
//    public static int sum(int a, int b, int c){
//        return a + b + c;
//    }
//    public static int sum(int a,int b,int c, int d){
//        return a + b + c + d;
//    }
}