习题：建立一个shape类，有circle和rect子类。建立一个shape类,有circle和rect子类.Shape类有zhouchang()和area()两种方法.（正方形）squ为rect子类，rect与cha()用于比较长宽的差。

Question

习题：建立一个shape类，有circle和rect子类。
建立一个shape类,有circle和rect子类. Shape 类有zhouchang()和area()两种方法.（正方形）squ为rect子类，rect与cha()用于比较长宽的差。

Answer 1

package javasky;
public abstract class Shape {
private double dLong = 0.00;
private double width = 0.00;
private double height = 0.00;

public double getDLong() {
return dLong;
}
public void setDLong(double long1) {
dLong = long1;
}
public double getWidth() {
return width;
}
public void setWidth(double width) {
this.width = width;
}
public double getHeight() {
return height;
}
public void setHeight(double height) {
this.height = height;
}
public void girth() {

}

public void area() {

}
}

package javasky;
public class Circle extends Shape { private final static double PI=3.14;
@Override
public void area() {
System.out.println( this.getDLong());
}
@Override
public void girth() {
System.out.println( this.getDLong());
}
}
package javasky;
public class Rect extends Shape {
@Override
public void area() {
System.out.println("面积为："+this.getDLong()*this.getWidth());
}
@Override
public void girth() {
System.out.println("周长为："+(double)2*this.getDLong()+(double)2*this.getWidth());
}

public void cha(){
//用于比较长宽的差,若长大于宽输出“长比宽大”，否则输出“宽比长大”。（正方形）
double result = this.getDLong()-this.getWidth();
String shape="长为"+this.getDLong()+"长为"+this.getWidth();
String str="";
if(result>0){
str="此图形为长方形。";
}else{
str="长等于宽，此图形为正方形。";
}
System.out.println(shape+str);
}

public Rect(double dlong,double width) {
System.out.println("赋初始值");
this.setDLong(dlong);
this.setWidth(width);
}
}
package javasky;
public class T {
public static void main(String[] args) {
Rect rect = new Rect(2.00,2.00);
rect.cha();
}
}