我的代码有问题。所以我有一个GeoFig对象和一个扩展GeoFig的圆。GeoFig 包含私有字段,例如面积、半径和周长。GeoFig还包含设置和获取这些字段的方法。我尝试创建一个 Circle 对象并实例化 get 方法,但它们不起作用。有什么建议吗?这是我下面的代码:
abstract public class GeoFig {
private double radius;
private double area;
private double circumference;
public void setRadius(double radius){
this.radius = radius;
}
public double getRadius(){
return this.radius;
}
public void setCircArea(double radius){
this.area = Math.pow(radius, 2) * Math.PI;
}
public double getCircArea(){
return this.area;
}
public void setCircumference(double radius){
circumference = 2*this.radius * Math.PI;
}
public double getCircumference(){
return this.circumference;
}
abstract String getMetrics();
public static void main(String[] args){
Circle circ = new Circle(2);
circ.getRadius();
}
}
public class Circle extends GeoFig {
public Circle(double radius) {
setRadius(radius);
setCircArea(radius);
setCircumference(radius);
}
@Override
public String getMetrics() {
return "Object of class Circle " +
"nRadius:" + getRadius() +
"nArea: " + getCircArea() +
"nCircumference: " + getCircumference();
}
}
我建议创建一个方法来显示您尝试创建的对象的内容。创建一个 ToSTRING 方法以查看对象的内容。
公共无效显示() {
double radius = getRadius() ;
double area= getArea() ;
double circumference= getCircumference() ;
System.out.println("Radius" + radius + "Area" + area + "Circumference" + circumference) ;
} 如果你在Windows上使用Eclipse控制+alt s,那么你可以创建一个ToSTRING方法。Mac Command + alt+ s. 希望有帮助
它对我来说效果很好。它打印2.0
abstract class GeoFig {
private double radius;
private double area;
private double circumference;
public void setRadius(double radius){
this.radius = radius;
}
public double getRadius(){
return this.radius;
}
public void setCircArea(double radius){
this.area = Math.pow(radius, 2) * Math.PI;
}
public double getCircArea(){
return this.area;
}
public void setCircumference(double radius){
circumference = 2*this.radius * Math.PI;
}
public double getCircumference(){
return this.circumference;
}
abstract String getMetrics();
public static void main(String[] args){
test circ = new test(2);
System.out.println(circ.getRadius()); }
}
public class test extends GeoFig {
public test(double radius){
setRadius(radius);
setCircArea(radius);
setCircumference(radius);
}
@Override
public String getMetrics(){
return "Object of class Circle " +
"nRadius:" + getRadius() +
"nArea: " + getCircArea() +
"nCircumference: " + getCircumference();
}
}
如果您希望它打印出结果,请尝试
System.out.println(circ.getRadius());
而不是
circ.getRadius();
您当前正在做的事情的问题是它获取半径但不对该值执行任何操作 - 您需要告诉它在获取半径后打印半径的值。