public class Circle {
public static void main(String[] args) {
int diameter; // (a) declare variable(s)
Circle2 c = new Circle2(50); // (b) create a circle with diameter 50
// (c) call to calculate perimeter
// without putting codes here i still get the
// output
// (d) call to calculate area
// (e) display area and perimeter of the circle
System.out.println("Area:" + c.calcArea());
// (e) display area and perimeter of the circle
System.out.println("Perimeter:" + c.calcPerimeter());
}
}
class Circle2 {
double diameter, radius;
public Circle2() {
diameter = 0.0;
radius = 0.0;
}
public Circle2(double cDiameter) {
// (f) construct a circle with a specified diameter and radius
diameter = cDiameter;
radius = diameter / 2;
}
public double calcPerimeter() {
// (g) calculate perimeter
return (22 * diameter) / 7;
}
public double calcArea() {
// (h) calculate area
return (22 * radius * radius) / 7;
}
}
这是一个考试问题,这意味着我无法添加或更改任何内容。我所能做的就是将代码填写到问题(a-h)中,我已尝试多次调用are和perimeter,但它不起作用
a:您必须声明将用方法填充的变量:
double perimeter;
double area;
b:正确
c,d:您将使用方法填充变量:
perimeter = c.calcPerimeter();
area = c.caclArea();
e:您必须显示它们,但您还是纠正了它,因为您直接打印了方法中的值,但问题是希望您打印出填充的变量
System.out.println("Area:" + area);
System.out.println("Perimeter:" + perimeter);
关于外围:您必须使用它代替return Math.PI * 2 * radius
return Math.PI * radius * radius