1. Method parameters
- Class as method parameter: the object of this class is passed
- Abstract class as a method parameter: the subclass object of the abstract class is passed
- Interface as a method parameter: Passed is the implementation class object of the interface
Code example:
package day0526;
public class demo3 {
public static void main(String[] args) {
Student student=new Student();
m1(student);
Zi zi=new Zi();
m2(zi);
Ziinter ziinter=new Ziinter();
m3(ziinter);
}
//普通类
public static void m1(Student student){
System.out.println(student.name);
}
//抽象类
public static void m2(Abstractclass a){
System.out.println(a.name);
}
//接口
public static void m3(Inters inters){
System.out.println(inters.name);
}
}
class Student{
String name="yyy";
}
abstract class Abstractclass{
String name="wtc";
}
class Zi extends Abstractclass {
}
interface Inters{
String name="yw";
}
class Ziinter implements Inters{
}2. Return value
- Ordinary class as a method return value: return the object of the class
- Abstract class as a method return value: return the subclass object of the abstract class
- Interface as a method return value: return the implementation class object of the interface
Code example:
package day0526;
public class demo4 {
public static void main(String[] args) {
Students a=m1();
System.out.println(a.name);
}
//普通类
public static Students m1(){
Students s=new Students();
return s;
}
//抽象类
public static AbPerson m2(){
AbPerson a=new PersonAb();
return a;
}
//接口
public static Interfuction m3(){
Interfuction i=new ZiImpl();
return i;
}
}
class Students{
String name="yyy";
}
abstract class AbPerson{
String name="wtc";
}
class PersonAb extends AbPerson{
}
interface Interfuction{
String name="wy";
}
class ZiImpl implements Interfuction{
}
