在Java中从派生类调用基类构造函数 [英] Calling a base class constructor from derived class in Java

问题描述

我有一个课程如下：

public class Polygon  extends Shape{

    private int noSides;
    private int lenghts[];

    public Polygon(int id,Point center,int noSides,int lengths[]) {
        super(id, center);
        this.noSides = noSides;
        this.lenghts = lengths;
    }
}

现在正多边形是一个多边形，其四面都是等于。我的正多边形的构造函数应该是什么？

Now a regular polygon is a polygon whose all sides are equal. What should be the constructor of my regular polygon?

public Regularpolygon extends Polygon{

//constructor ???
}

推荐答案

public class Polygon  extends Shape {    
    private int noSides;
    private int lenghts[];

    public Polygon(int id,Point center,int noSides,int lengths[]) {
        super(id, center);
        this.noSides = noSides;
        this.lenghts = lengths;
    }
}

public RegularPolygon extends Polygon {
    private static int[] getFilledArray(int noSides, int length) {
        int[] a = new int[noSides];
        java.util.Arrays.fill(a, length);
        return a;
    }

    public RegularPolygon(int id, Point center, int noSides, int length) {
        super(id, center, noSides, getFilledArray(noSides, length));
    }
}

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