Java第一次实验 参考答案

题目地址： http://090612.iteye.com/blog/645021

第一题:

public class JavaTestOne {

	public static void main(String[] args) {
		Rectangle Rec = new Rectangle(5,4);//Rectangle(length,width)
		Square Squ = new Square(6);//Square(length)
		System.out.println("The rectangle's area is "+Rec.calcArea());
		System.out.println("The rectangle's perimeter is "+Rec.calcPerimeter());
		System.out.println("The square's area is "+Squ.calcArea());
		System.out.println("The square's perimeter is "+Squ.calcPerimeter());
	}
}

class Rectangle{
	
	int length;
	int width;
	
	int calcArea(){
		return length*width;
	}
	
	int calcPerimeter(){
		return 2*(length+width);
	}
	
	public Rectangle(int x,int y){
		length=x;
		width=y;
	}
}

class Square extends Rectangle{
	
	int calcArea(){
		return length*length;
	}
	
	int calcPerimeter(){
		return 4*length;
	}
	
	Square(int z){
		super(z, z);
		length=z;
	}
}

注：理论上来讲，正方形不应该作为长方形的子类！

第二题：

public class JavaTestTwo {

	public static void main(String[] args) {
		Rectangle Rec = new Rectangle(3,4);//Rectangle(length,width)
		Square Squ = new Square(2);//Square(length)
		Rec.pringtItMyWay('#');
		Rec.pringtItMyWay();
		Squ.pringtItMyWay('$');
		Squ.pringtItMyWay();
	}
}

interface Printable{
	void pringtItMyWay();
	void pringtItMyWay(char a);
}

class Rectangle implements Printable{
	int i,j;
	int length;
	int width;
	
	int calcArea(){
		return length*width;
	}
	
	int calcPerimeter(){
		return 2*(length+width);
	}
	
	public void pringtItMyWay(){
		System.out.println("The rectangle's length is "+length);
		System.out.println("The rectangle's width is "+width);
		System.out.println("The rectangle's area is "+calcArea());
		System.out.println("The rectangle's perimeter is "+calcPerimeter());
	}
	
	public void pringtItMyWay(char a) {
		for (i=0;i<width;i++){
			for (j=0;j<length;j++)
				System.out.print(a);
				System.out.println("");
		}
	}
	
	public Rectangle(int x,int y){
		length=x;
		width=y;
	}
}

class Square extends Rectangle implements Printable{
	
	int calcArea(){
		return length*length;
	}
	
	int calcPerimeter(){
		return 4*length;
	}
	
	public void pringtItMyWay(){
		System.out.println("The square's length is "+length);
		System.out.println("The square's area is "+calcArea());
		System.out.println("The square's perimeter is "+calcPerimeter());
	}
	
	public void pringtItMyWay(char a){
		for (i=0;i<length;i++){
			for (j=0;j<length;j++)
				System.out.print(a);
				System.out.println("");
		}
	}
	
	Square(int x){
		super(x,x);
		length=x;
	}
}

注：同样的，正方形本不应该作为长方形的子类出现。

本参考答案系菜鸟编写，请各位大虾们在留言内指出错误并提出修改建议，本人不胜感激！