我需要编写一个程序来计算圆的面积,我似乎一切正常,除非我运行程序并输入面积计算结果为零的值。
public class Circle {
private double radius;
private double area;
public Circle() {
radius = 0;
area = 0;
}
public Circle(double radius) {
this.radius = radius;
}
public double getRadius() {
return radius;
}
public void setRadius(double radius) {
this.radius = radius;
}
public double getArea() {
return area;
}
public void setArea(double area) {
area = radius * radius * Math.PI;
}
public String toString() {
return "The radius of the circle is: " + radius + ", and the area is: " + area;
}
}
我需要更改什么,以便当我的测试代码调用 toString 时它会输出计算面积?