请问这段程序怎么会报错呢 ？

Question

public class CircleWithConstructors
{
double radius;
double findArea()
{
return radius*radius*3.1415926;
}
public static void main(String[] args)
{
    CircleWithConstructors myCircle = new CircleWithConstructors(5.0);
System.out.println("The area of the circle of       radius"+myCircle.radius+"is"+myCircle.findArea());
CircleWithConstructors yourCircle=new CircleWithConstructors();
System.out.println("The area of the circle of radius"+yourCircle.radius+"is"+yourCircle.findArea());
}
}

Answer 1

你没有 CircleWithConstructors(double d)这样的构造函数呀。

Answer 2

我加了这个构造函数 还是报错  
出现这样的报错信息   高手指点 ！！！！！
--------------------Configuration: Batch Process - j2sdk1.4.2 <Default>--------------------
D:\java例题\java 程序\CircleWithConstructors\CircleWithConstructors.java:10: '.class' expected
CircleWithConstructors (double radius)
                                               ^
D:\java例题\java 程序\CircleWithConstructors\CircleWithConstructors.java:11: ')' expected
    CircleWithConstructors myCircle = new CircleWithConstructors(5.0);
                                                                             ^
2 errorsProcess completed.

Answer 3

public class CircleWithConstructors {
double radius; public CircleWithConstructors(double d) {
radius = d;
} public CircleWithConstructors() {
} double findArea() {
return radius * radius * 3.1415926;
} public static void main(String[] args) {
CircleWithConstructors myCircle = new CircleWithConstructors(5.0);
System.out.println("The area of the circle of       radius"
+ myCircle.radius + "is" + myCircle.findArea());
CircleWithConstructors yourCircle = new CircleWithConstructors();
System.out.println("The area of the circle of radius"
+ yourCircle.radius + "is" + yourCircle.findArea());
}
}

Answer 4

CircleWithConstructors myCircle = new CircleWithConstructors(5.0);
留意构造器里面的5.0，你使用时没有声明。

Answer 5

我看楼上的大哥，还是跟他说说java里怎么用构造函数吧

Answer 6

public class CircleWithConstructors {
        double radius;        public CircleWithConstructors(double d) {
                radius = d;
        }        public CircleWithConstructors() {
        }        double findArea() {
                return radius * radius * 3.1415926;
        }        public static void main(String[] args) {
                CircleWithConstructors myCircle = new CircleWithConstructors(5.0);
                System.out.println("The area of the circle of radius"
                                + myCircle.radius + "is" + myCircle.findArea());
                CircleWithConstructors yourCircle = new CircleWithConstructors();
                System.out.println("The area of the circle of radius"
                                + yourCircle.radius + "is" + yourCircle.findArea());
        }
}上面这段代码是没有错的