public abstract class Shape {
public abstract double area();
}
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public class Rectangle extends Shape {
double length;//矩形的長(zhǎng)
double width;//矩形的寬
public Rectangle(double len,double wid) {//構(gòu)造方法
this.length = len;
this.width = wid;
}
@Override
public double area() {//返回矩形的面積
double area = length * width;
return area;
}
}
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public class Circle extends Shape {
double radius;//圓的半徑
public Circle(double rad) {//構(gòu)造方法
this.radius = rad;
}
@Override
public double area() {//返回園的面積
double area = 3.14 * radius * radius;
return area;
}
}
--------------------------------------------------
public class MyTest {//測(cè)試類
public static void main(String[] args) {
Rectangle rec = new Rectangle(4.7, 5.1);
double recArea = rec.area();
System.out.println("矩形的長(zhǎng)5.1,寬4.7,面積：" + recArea);

Circle cir = new Circle(6.4);
double cirArea = cir.area();
System.out.println("園的半徑6.4,面積：" + cirArea);
}
}