<명품 JAVA Programming> - Chapter5 연습문제(1, 2, 3, 4, 5, 6, 7, 8)

1. 다음 main()메소드와 실행 결과를 참고하여 상속받은 ColorTV 클래스를 작성하라.

 

package chapter5;

class TV {
	private int size;
	public TV(int size) {this.size = size;}
	protected int getSize() {return size;}
}

public class ColorTV extends TV{
	private int nColors;
	public ColorTV(int size, int nColors) {
		super(size);
		this.nColors = nColors;
	}
	public void printProperty() {
		System.out.println(getSize() + "인치 " + nColors + "컬러");
	}
	public static void main(String[] args) {
		ColorTV myTV = new ColorTV(32, 1024);
		myTV.printProperty();
	}
}

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2. 다음 main()메소드와 실행 결과를 참고하여 문제 1의 ColorTV를 상속받는 IPTV 클래스를 작성하라.

 

package chapter5;

class TV2 {
	private int size;
	public TV2(int size) {this.size = size;}
	protected int getSize() {return size;}
}

class ColorTV2 extends TV2{
	private int nColors;
	public ColorTV2(int size, int nColors) {
		super(size);
		this.nColors = nColors;
	}
	protected int getnColors() {return nColors;}
	public void printProperty() {
		System.out.println(getSize() + "인치 " + nColors + "컬러");
	}
}
	
public class IPTV extends ColorTV2 {
	private String ip;
	public IPTV(String ip, int size, int nColors) {
		super(size, nColors);
		this.ip = ip;
	}
	public void printProperty() {
		System.out.println("나의 IPTV는 " + ip + " 주소의 " + getSize() + "인치 " + getnColors() + "컬러");
	}
	
	public static void main(String[] args) {
		IPTV myTV = new IPTV("192.1.1.2", 32, 2048);
		myTV.printProperty();
	}
}

 

 

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3. Coverter 클래스를 상속받아 원화를 달러로 변환하는 Won2Dollar 클래스를 작성하라.

 

package chapter5;
import java.util.Scanner;

abstract class Converter {
	abstract protected double convert(double src);
	abstract protected String getSrcString();
	abstract protected String getDestString();
	protected double ratio;
	
	public void run() {
		Scanner scanner = new Scanner(System.in);
		System.out.println(getSrcString() + "을 " + getDestString() + "로 바꿉니다.");
		System.out.print(getSrcString() + "을 입력하세요>> ");
		double val = scanner.nextDouble();
		double res = convert(val);
		System.out.println("변환 결과: " + res + getDestString() + "입니다.");
		scanner.close();
	}
}
public class Won2Dollar extends Converter{
	public Won2Dollar(double ratio) {
		this.ratio = ratio;
	}
	@Override
	protected double convert(double src) {
		return src / ratio;
	}
	
	@Override
	protected String getSrcString() {
		return "원";
	}
	
	@Override
	protected String getDestString() {
		return "달러";
	}
	public static void main(String[] args) {
		Won2Dollar toDollar = new Won2Dollar(1200);
		toDollar.run();
	}

}

 

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4. Converter클래스를 상속받아 Km를 mile(마일)로 변환하는 km2Mile클래스를 작성하라. main() 메소드와 실행 결과는 다음과 같다.

 

package chapter5;
import java.util.Scanner;

abstract class Converter2 {
	abstract protected double convert(double src);
	abstract protected String getSrcString();
	abstract protected String getDestString();
	protected double ratio;
	
	public void run2() {
		Scanner scanner = new Scanner(System.in);
		System.out.println(getSrcString() + "을 " + getDestString() + "로 바꿉니다.");
		System.out.print(getSrcString() + "을 입력하세요>> ");
		double val = scanner.nextDouble();
		double res = convert(val);
		System.out.println("변환 결과: " + res + getDestString() + "입니다.");
		scanner.close();
	}
}
public class Km2Mile extends Converter{
	public Km2Mile(double ratio) {
		this.ratio = ratio;
	}
	@Override
	protected double convert(double src) {
		return src / ratio;
	}
	
	@Override
	protected String getSrcString() {
		return "Km";
	}
	
	@Override
	protected String getDestString() {
		return "Mile";
	}
	public static void main(String[] args) {
		Km2Mile toMile = new Km2Mile(1.6);
		toMile.run();
	}

}

 

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5. Poin를 상속받아 색을 가진 점을 나타내는 ColorPoint 클래스를 작성하라.

 

package chapter5;

class Point {
	private int x, y;
	public Point(int x, int y) {this.x = x; this.y = y;}
	public int getX() {return x;}
	public int getY() {return y;}
	protected void move(int x, int y) {this.x = x; this.y = y;}
}
public class ColorPoint extends Point{
	private String color;
	public ColorPoint(int x, int y, String color) {
		super(x, y);
		this.color = color;
	}
	public void setXY(int x, int y) {move(x,y);}
	public void setColor(String color) {this.color = color;}
	public String toString() {
		return color + "색의 " + "(" + getX() + "," + getY() + ")의 점"; 
	}
	public static void main(String[] args) {
		ColorPoint cp = new ColorPoint(5, 5, "YELLOW");
		cp.setXY(10, 20);
		cp.setColor("RED");
		String str = cp.toString();
		System.out.println(str + "입니다.");
	}
}

 

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6. Point를 상속받아 색을 가진 점을 나타내는 ColorPoint 클래스를 작성하라. 다음 main() 메소드를 포함하고 실행 결과와 같이 출력되게 하라.

 

package chapter5;

class Point2 {
	private int x, y;
	public Point2() {this.x = 0; this.y = 0;}	//기본 생성자 추가
	public Point2(int x, int y) {this.x = x; this.y = y;}
	public int getX() {return x;}
	public int getY() {return y;}
	protected void move(int x, int y) {this.x = x; this.y = y;}
}
public class ColorPoint2 extends Point2{
	private String color;
	
	public ColorPoint2() {	//기본 생성자 추가
		this.color = "Black";
	}
	public ColorPoint2(int x, int y) {
		super(x, y);
	}
	public void setXY(int x, int y) {move(x,y);}
	public void setColor(String color) {this.color = color;}
	public String toString() {
		return color + "색의 " + "(" + getX() + "," + getY() + ")의 점"; 
	}
	public static void main(String[] args) {
		ColorPoint2 zeroPoint = new ColorPoint2();
		System.out.println(zeroPoint.toString() + "입니다.");
		
		ColorPoint2 cp = new ColorPoint2(10, 10);
		cp.setXY(5, 5);
		cp.setColor("RED");
		System.out.println(cp.toString() + "입니다.");
	}
}

 

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7. Point를 상속받아 3차원의 점을 나타내는 Point3D 클래스를 작성하라.

 

package chapter5;

class Point3 {
	private int x, y;
	
	public Point3(int x, int y) {this.x = x; this.y = y;}
	public int getX() {return x;}
	public int getY() {return y;}
	protected void move(int x, int y) {this.x = x; this.y = y;}
}
public class Point3D extends Point3{
	private int z;
	public Point3D(int x, int y, int z) {
		super(x, y);
		this.z = z;
	}
	
	public void moveUp() {z += 1;}
	
	public void moveDown() {z -= 1;}
	public void move(int x, int y, int z) {
		move(x, y); this.z = z;
	}
	public String toString() {
		return "(" + getX() + "," + getY() + "," + z + ")의 점"; 
	}

	public static void main(String[] args) {
		Point3D p = new Point3D(1, 2, 3);
		System.out.println(p.toString() + "입니다.");
		
		p.moveUp();
		System.out.println(p.toString() + "입니다.");
		p.moveDown();
		p.move(10, 10);
		System.out.println(p.toString() + "입니다.");
		
		p.move(100, 200, 300);
		System.out.println(p.toString() + "입니다.");
	}
}

 

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8. Point를 상속받아 양수의 공간에서만 점을 나타내는 PositivePoint 클래스를 작성하라.

 

package chapter5;

class Point4 {
	private int x, y;
	
	public Point4() {this.x = 0; this.y = 0;}
	public Point4(int x, int y) {this.x = x; this.y = y;}
	public int getX() {return x;}
	public int getY() {return y;}
	protected void move(int x, int y) {this.x = x; this.y = y;}
}
public class PositivePoint extends Point4{
	public PositivePoint(int x, int y) {
		super(x, y);
		if(x < 0 || y < 0) move(0, 0);
	}
	public PositivePoint() {
	}
	@Override
	protected void move(int x, int y) {
		if(x >= 0 && y >= 0) super.move(x, y);
	}
	
	public String toString() {
		return "(" + getX() + "," + getY() + ")의 점"; 
	}
	public static void main(String[] args) {
		PositivePoint p = new PositivePoint();
		p.move(10, 10);
		System.out.println(p.toString() + "입니다.");
		
		p.move(-5, 5);
		System.out.println(p.toString() + "입니다.");
		
		PositivePoint p2 = new PositivePoint(-10, -10);
		System.out.println(p2.toString() + "입니다.");
	}
}