testshape.java

有关于java中的继承

public class TestShape{
	public static void main(String[] args){
	}
}
class Rect{
	double chang;
	double kuan;
	public Rect(){}
	public Rect(double c,double k){
		chang=c;
		kuan=k;
	}
	public double line(){
		return (chang+kuan)*2;
	}
	public double area(){
		return chang*kuan;
	}
}