Question

有人可以向我解释一下参考（非原始）数据类型的工作原理吗？主要是如何将数据输入到它们以及如何检查它们持有的数据？你可以用这个代码作为例子。

public class Example{
    public static void main(String [] args){
        Circle c= new Circle();
        System.out.println():
    }
}

public class Circle{
    Circle round;
    public Circle(){
    }
    public Circle numPlacment(){
        round=new Circle(2);     //I would like circle to contain the value of '2'
        return round;
    }
    public String toString(){
        StringBuilder b= new StringBuilder();
        b.append(round);
        return String.format("%4s",b);
    }
}

Answer 1

你的代码有点荒谬。看看它应该如何完成可能更容易：

public class Example{
    public static void main(String [] args) {
        // create a new circle with radius 2
        Circle c= new Circle(2);  
        // Print that circle
        System.out.println(c);    
    }
}

class Circle {
    // The instance variable that stores the radius for this circle
    double radius;

    // Create a new Circle given a radius
    public Circle(double radius) {
      // assign the given radius parameter to the instance variable
      this.radius = radius;
    }
    public String toString() {
        StringBuilder b= new StringBuilder();
        b.append(radius);
        return String.format("%4s",b);
    }
}

Java在非原始数据类型中输入值

1 个答案: