如何在参数化构造函数中使用枚举？

Question

我有一个任务要求我创建枚举类型.我的问题是,在我初始化它们之后,如何将它们引入默认和参数化构造函数？我试过以下但它不起作用......任何想法？谢谢

package magazine;
import paperPublication.PaperPublication;


public class Magazine extends PaperPublication {

    private enum paperQuality {LOW, NORMAL, HIGH};
    private enum issuingFrequency {WEEKLY, MONTHLY, YEARLY};

    public Magazine() {
        paperQuality = null;   //doesn't work
        issuingFrequency = null;    //doesn't work
    }

    public Magazine (double price, int numberOfPages, enum paperQuality  //doesn't work, enum issuingFrequency  //doesn't work) {

    }
}

Answer 1

这是一个类型定义:

private enum paperQuality ...

但是你实际上没有声明该类型的字段.尝试这样的事情:

private enum PaperQuality {...};
private PaperQuality paperQuality;

第一行定义PaperQuality枚举,定义任何PaperQuality可以容纳的各种值.第二行创建一个名为该类型的私有字段paperQuality.构造函数可能如下所示:

public Magazine (double price, int numberOfPages, PaperQuality paperQuality) {
    ...
    this.paperQuality = paperQuality;
}