오버라이딩(day20)

package day21.ex04_Override;

public class Airplane {
	public void land() {
		System.out.println("착륙합니다.");
	}
	public void fly() {
		System.out.println("일반비행합니다.");
	}
	public void takeoff() {
		System.out.println("이륙합니다.");
	}
}

package day21.ex04_Override;

public class SupersonicAirplane extends Airplane{
	public static final int NORMAL = 1;
	public static final int SUPERSONIC = 2;
	
	public int flyMode = NORMAL;
	
	@Override
	public void fly() {
		if(flyMode == SUPERSONIC) {
			System.out.println("초속비행합니다.");
		}else {
			super.fly();
		}
	}
	
	
}

package day21.ex04_Override;

public class SupersonicAirplane_Ex {
	public static void main(String[] args) {
		
	SupersonicAirplane sa = new SupersonicAirplane();
	sa.takeoff();
	sa.fly();
	sa.flyMode = SupersonicAirplane.SUPERSONIC;
	sa.fly();
	sa.flyMode = SupersonicAirplane.NORMAL;
	sa.fly();
	sa.land();

	}
}

package day21.ex04_Override;

public class Car {
	String name;
	int wheel;
	
	void run() {
		System.out.println("평범한 차가 출발합니다.");
	}
}

package day21.ex04_Override;

public class SportsCar extends Car{
	int select;
	String name;
	
	@Override
	void run() {
		if(select == 1) {
			this.name = "스포츠카가 출발합니다";
			System.out.println(this.name);
		}else if(select == 2) {
			super.run();
		}
		
	}
}

package day21.ex04_Override;

public class SportsCar_Ex {
	public static void main(String[] args) {
		
		SportsCar c1 = new SportsCar();
		c1.select = 1;
		
		c1.run();
	}
	
}

package day21.ex04_Override;

public class Calculator {
	double areaCircle(double r) {
		System.out.println("Calculator 객체의 areaCirlce() 실행");
		return 3.14159 * r * r;
	}
}

package day21.ex04_Override;

public class Computer extends Calculator{
	@Override
	double areaCircle(double r) {
		System.out.println("Computer 객체의 areaCircle() 실행");
		return Math.PI * r * r;
	}
}

package day21.ex04_Override;

public class Computer_Ex {
	public static void main(String[] args) {
		int r = 10;
		Calculator calc = new Calculator();
		System.out.println("원면적 : " + calc.areaCircle(r));
		System.out.println();
		Computer com = new Computer();
		System.out.println("원면적 : " + com.areaCircle(r));
	}
}