상속, 다형성(Polymorphism) 기본 실습

//다형성 실습

Empolyee 추상화 클래스
public abstract class Employee {
	public String name;
	
	public void methodA(){
		System.out.println("Employee methodA");
	}
//	public void method(){
//		System.out.println("Employee method");
//	}

	public abstract void method();
	
}

 
 
Engineer 클래스 (Empolyee 상속받음)
public class Engineer extends Employee {
	public String name;
	
	public void methodB(){
		System.out.println("Engineer methodB");
	}
	
	//오버라이드
	public void method(){
		System.out.println("Engineer method");
	}
}
 

 
 
 
Manager 클래스 (Empolyee 상속받음) 
public class Manager extends Employee {
	
	public void methodC(){
		System.out.println("Manager methodC");
	}
	
	//오버라이드
	public void method(){
		System.out.println("Manager method");
	}
}

main 클래스
public class ExamEx01 {
	public static void main(String[] args) {
		Engineer e = new Engineer();
		
		e.methodA();
		e.methodB();
		e.method();
		
		//다형성
		Employee emp = new Engineer();
		emp.methodA();
		//emp.methodB();  //자식전용이기 때문에 사용하지 못함
		emp.method(); //오버라이드됨 : 자식것을 사용(Engineer)
		
		emp = new Manager();
		emp.method();  //오버라이드됨 : 자식것을 사용 (Manager)
	}
}

 

 

 

 

출력물

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Employee methodA
Engineer methodB
Engineer method
Employee methodA
Engineer method        //오버라이드됨
Manager method        //오버라이드됨

---