java可变参数

package exercise03_jdknews;

import java.util.ArrayList;
import java.util.Scanner;

/**
 * 可变参数
 * 格式
 *      修饰符 返回值类型 方法名(数据类型... 变量名){}
 * @author lgt
 *
 */
public class KebianCanShu {
    public static void main(String[] args) {
        int a = 20;
        int b = 23;
        int result1 = sum(a,b);

        System.out.println(result1);

        //可变参数的调用类型
        System.out.println("可变参数的调用类型");
        System.out.println(sum1(1,2,3,4,5,6,7,8,9,10));
        int[] i1 = {1,23, 32,3};
        int[] i2 = {2,3,4,5,6,7,8,9,10};
        int[] i3 = {1,2,3,4,5,6,7,8,9,10};
        System.out.println("参数个数为：" + i1.length + "，sum1(i1) 其和为：" + sum1(i1));
        System.out.println("参数个数为：" + i2.length + "，sum1(i2) 其和为：" + sum1(i2));
        System.out.println("参数个数为：" + i3.length + "，sum1(i3) 其和为：" + sum1(i3));


        //输入几个整数，求和，个数不确定方式2
        System.out.println("输入几个整数，求和，个数不确定方式2");
        Scanner sc = new Scanner(System.in);
        ArrayList<Integer> list = new ArrayList<Integer>();
        while(true){
            Integer x = sc.nextInt();
            if(x != 0){
                list.add(x);
            }else{
                break;
            }
        }
        sc.close();
        System.out.println(sum2(list));

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

    public static int sum1(int... a){
        int sum = 0;
        for(int i : a){
            sum += i;
        }
        return sum;
    }

    public static Integer sum2(ArrayList<Integer> list){
        Integer sum = 0;
        for(Integer i : list){
            sum += i;
        }
        return sum;
    }
}