1 this关键字
package com.Hani;
class E{
private F b=null;
public void fun(){
this.b=new F (this);
this.b.fun();
}
public void print(){
System.out.println("Hello World!!!");
}
};
class F{
private E a=null;
public F(E a){
this.a=a;
}
public void fun(){
this.a.print();
}
};
public class DemoThis {
public static void main(String args[]){
new E().fun();
}
}
2 父类
package com.Hani;
abstract class A{
public abstract void fun();
}
class B extends A{
public void fun(){
System.out.println("Hello World!");
}
}
public class DemoAbstract{
public static void main(String args[]){
B b=new B();
b.fun();
}
}
3.
package com.Hani;
abstract class C{
private String name;
public C(String name){
this.name=name;
}
public String getName(){
return this.name;
}
public abstract void fun();
};
class D extends C {
public D(String name){
super(name);
}
public void fun() {
System.out.println(super.getName());
}
};
public class DemoAbstrsct1 {
public static void main(String args[]){
D d=new D("爱豆鹿晗");
d.fun();
}
}
4.工人学生
public abstract class Person {
private String name;
private int age;
public Person(String name,int age){
this.name=name;
this.age=age;
}
public Person() {
super();
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public abstract String speak();
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
public class Student extends Person {
private float score;
public Student(){
}
public Student(String name,int age,float score) {
// TODO 自动生成的构造函数存根
super(name,age);
this.score=score;
//this.setScore(score);
}
@Override
public String speak() {
// TODO 自动生成的方法存根
return "我是"+super.getName()+", 我"+super.getAge()+"岁了,"+"我的成绩是"+this.score;
}
public float getScore() {
return score;
}
public void setScore(float score) {
this.score = score;
}
}
public class Worker extends Person {
private float rewards;
public Worker(String name, int age, float rewards) {
// TODO 自动生成的构造函数存根
super(name, age);
this.rewards=rewards;
}
@Override
public String speak() {
// TODO 自动生成的方法存根
return "我是"+super.getName()+", 我"+super.getAge()+"岁了,"+"我的工资是"+this.rewards;
}
public float getRewards() {
return rewards;
}
public void setRewards(float rewards) {
this.rewards = rewards;
}
}
package cn.wzx.www;
public class DemoWoSt {
public static void main(String[] args) {
// TODO 自动生成的方法存根
Person student =new Student("张三",18,59.0f);
Person worker =new Worker("李四",30,3600.8f);
print(student.speak());
print(worker.speak());
}
private static void print(String speak) {
System.out.println(speak);
}
}
5.抽象类
package cn.dede.w;
abstract class A3
{
public abstract void fun();
}
class B3 extends A3
{
public void fun()
{
System.out.println("yeah");
}
}
public class AbstractDemo3
{
public static void main(String args[])
{
A3 a=new B3();
a.fun();
}
}
