java之final关键字

 1 final class Person {
 2     String name ="zs";
 3     //3. 此处不赋值会报错
 4     //final int age;
 5     final int AGE = 10;  
 6 }
 7 public class Demo01 {
 8     public static void main(String[] args) {
 9         //1. 基本数组类型为常量，无法修改
10         final int i = 9;
11         //i = 10;
12        
13         //2. 地址不能修改，但是对象本身的属性可以修改
14         Person p = new Person();
15         p.name = "lisi";
16         final int[] arr = {1,2,3,45};
17         arr[3] = 999;
18         //arr = new int[]{1,4,56,78};
19     }
20 }

 1 class Person {
 2     public final void say() {
 3         System.out.println("说....");
 4     }
 5     public void eat() {
 6         System.out.println("吃...");
 7     }
 8 }
 9 class Teacher extends Person {
10     //1. final修饰的方法不能被重写，但此方法仍然被继承
11     /*@Override
12     public void say() {
13         System.out.println("老师在一本正经的说...");
14     }*/
15     
16     public void eat() {
17         System.out.println("老师在大口大口的吃...");
18     }
19 }
20 public class Demo02 {
21     public static void main(String[] args) {
22         Teacher t = new Teacher();
23         t.say();
24     }    
25 }