java学习之路 之 面向对象编程-可变个参数-练习题

public class VarArgsTest {/*public static int avg(int a, int  b) {return (a + b) / 2;}public static int avg(int a, int  b, int c) {return (a + b + c) / 3;}public static int avg(int a, int  b, int c, int d) {return (a + b + c + d) / 4;}*//*public static int avg(int[] nums) { // 不灵活return 0;}*/public static int avg(int... nums) { // 可变参数 0~n个参数, 可变参数只能放在参数列表的最后int sum = 0;for (int i = 0; i < nums.length; i++) {sum += nums[i];}return sum / nums.length;}public static  void test1(String book){System.out.println("****与可变形参方法构成重载的test1方法****");}public static void test1(String ... books){System.out.println("****形参长度可变的test1方法****");}public static void main(String... args) {System.out.println(avg(10, 15));//System.out.println(avg(new int[]{10, 15})); 编译器会自动翻译成这样System.out.println(avg(10, 15, 30));//System.out.println(avg(new int[]{10, 15, 30}));System.out.println(avg(10, 15, 30, 50));int[] arr = {3, 8, 9, 10};System.out.println(avg(arr));System.out.println(avg());//System.out.println(avg(new int[]{}));test1("abc"); // 优先匹配一个参数的精确匹配String[][] arrarr = {{"aaa", "bbb", "ccc"}, {"111", "222"}, {"你", "他", "我"}};}}