Java 开启枚举值

Question

我希望用户输入 1 到 7 之间的数字。如果数字是 1，则打印出这是星期一。如果数字是 2，则打印出这是星期二，依此类推。

以下代码可以编译，但逻辑上不正确。

请参阅评论以了解需要帮助的地方:

import java.util.Scanner;

public class Test {
    private enum Week {
        MONDAY("1"), TUESDAY("2"), WEDNESDAY("3"), 
        THURSDAY("4"), FRIDAY("5"), SATURDAY("6"), SUNDAY("7");
        private String value;

        private Week(String value) {
            this.value = value;
        }
    }

    public static void main(String[] args) {

        // How to instantiate this correctly, so that it doesn't only point to one value
        Week week = Week.MONDAY;
        System.out.print("Enter a number: ");
        Scanner input = new Scanner(System.in);
        String userInput = input.next();

        // The switch parameter is not correct. This is what needs to be fixed.
        // I want to use this case layout.
        //The enums each have a value. The user enters a value. I want to switch over userInput.
        switch (week) {
            case MONDAY: System.out.println("That's Monday"); break;
            case TUESDAY: System.out.println("That's Tuesday"); break;
            case WEDNESDAY: System.out.println("That's Wednesday"); break;
            case THURSDAY: System.out.println("That's Thursday"); break;
            case FRIDAY: System.out.println("That's Friday"); break;
            case SATURDAY: System.out.println("That's Saturday"); break;
            case SUNDAY: System.out.println("That's Sunday"); break;
            default: break;
        }
    }
}

Answer 1

在 Week 枚举中创建一个 get 方法，以便通过给定字符串获取 Week，例如:

public enum Week {
 ...
 public Week getWeek(String key) {
  ... logic lookup 
  ... obtain a Week(weekResult) with that key
  return weekResult;
 }
}

或者您可以尝试使用 Enum 方法 valueOf(...)。

我想，有了这个你就有必要开始了吧？