상자의 정보 (함수 재정의)

public class Box {

private int x;

private int y;

private int z;

private boolean empty;

 

public String toString() {

String rslt = "가로: " + x + "cm 세로: " + y + "cm 높이: " + z + "cm";

return rslt;

  }

 

public void fillBox() {

this.empty = false;

  }

 

public void emptyBox() {

this.empty = true;

  }

 

public int getVolume() {

return x * y * z;

  }

 

public double getWeight() {

return 1.1 * getVolume();

  }

 

public Box(int x, int y, int z) {

this.x = x;

this.y = y;

this.z = z;

emptyBox();

  }

}

 

 

public class MaterialBox extends Box{

private String attribute;

 

public void setAttribute(String attribute) {this.attribute = attribute;};

public String getAttribute() {return attribute;};

 

public double getWeight() {

if (attribute.equals("paper")) {

return getVolume() * 1.5;

} else if (attribute.equals("wood")) {

return getVolume() * 2.5;

} else {

return getVolume() * 1.1;

}

  }

 

public String toString() {

return super.toString() + "\n재질: " + attribute;

  }

 

public MaterialBox(int x, int y, int z, String attribute) {

super(x, y, z);

this.attribute = attribute;

  } 

}

 

 

public class Practice_74 {

 

public static void main(String[] args) {

Box box1 = new Box(10, 20, 30);

MaterialBox box2 = new MaterialBox(2, 3, 4, "wood");

MaterialBox box3 = new MaterialBox(4, 3, 2, "paper");

 

System.out.println("box1의 정보입니다.");

System.out.println(box1.toString() + "\n부피: " + box1.getVolume() + "\n무게: " + box1.getWeight());

 

System.out.println("box2의 정보입니다.");

System.out.println(box2.toString() + "\n부피: " + box2.getVolume() + "\n무게: " + box2.getWeight());

 

System.out.println("box3의 정보입니다.");

System.out.println(box3.toString() + "\n부피: " + box3.getVolume() + "\n무게: " + box3.getWeight());

}

 

}

 

 

결과: