形参个数可变的方法

定义方法时，在最后一个形参的类型后增加三点(...)，则表明该形参可以接受多个参数值，多个参数值被当成数组传入

形参个数可变的参数本质就是一个数组参数，如：

public static void test(int a,String...books);

public static void test(int a,String[] books);

这两种方法的效果一样。

例如：

定义一个教师类，包含姓名、性别、职称、年龄、基本工资
定义两个构造方法：
（1）采用姓名、性别、年龄作为参数
（2）将姓名、性别、职称、年龄、基本工资作为参数进行初始化，
普通方法：
（1）输出教师的姓名、年龄、职称
（2）输出教师的平均基本工资
（3）输出教师的平均年龄

 1 public class Answer {
 2     public static void main(String[] args) {
 3         Teacher teacher1 = new Teacher("111","男","222",20,"9999");
 4         Teacher teacher2 = new Teacher("123","女","222",21,"8888");
 5         new Teacher().print1(teacher1);
 6         new Teacher().print2(teacher1,teacher2);
 7         new Teacher().print3(teacher1,teacher2);
 8     }
 9 
10 }
11 class Teacher{
12     private String name;
13     private String sex;
14     private String value;
15     private int age;
16     private String sala;
17     
18     public Teacher() {
19     }
20     public Teacher(String name, String sex, int age) {
21         super();
22         this.name = name;
23         this.sex = sex;
24         this.age = age;
25     }
26     public Teacher(String name, String sex, String value, int age, String sala) {
27         super();
28         this.name = name;
29         this.sex = sex;
30         this.value = value;
31         this.age = age;
32         this.sala = sala;
33     }
34     public void print1(Teacher teacher) {
35         System.out.println(teacher.name );
36         System.out.println(teacher.age );
37         System.out.println(teacher.sala );
38     }
39     public void print2(Teacher...teacher) {
40         int sum = 0;
41         for(int i = 0;i<teacher.length ;i++) {
42             sum += Integer.parseInt(teacher[i].value );
43         }
44         System.out.println(sum/teacher.length );
45     }
46     public void print3(Teacher...teacher) {
47         int sum = 0;
48         for(int i = 0;i<teacher.length ;i++) {
49             sum += teacher[i].age;
50         }
51         System.out.println(sum/teacher.length );
52     }
53 }

元素个数不清楚的（可以无数个，可以0个）

形参个数可变的方法

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