[Java] Branch enum with switch statement

Introduction

Note that I was addicted to branching enum type variables with a switch statement.

What I tried to do

There was an enum like this and I tried to branch the passed enum type value with a switch statement.

`HogeType.java`


public enum HogeType {
  NONE(0),
  FIRST(1),
  SECOND(2)
}

Bad example

public void hoge(HogeType hogeType){
  switch(hogeType){
    case HogeType.FIRST:
      System.out.println("first");
      break;
    case HogeType.SECOND:
      System.out.println("second");
      break;
    default:
      System.out.println("none");
  }
}

There was an error in the case HogeType.FIRST: part of this. The content is ʻan enum switch case label must be the unqualified name of an enumeration constant`.

Correct answer

public void hoge(HogeType hogeType){
  switch(hogeType){
    case FIRST:
      System.out.println("first");
      break;
    case SECOND:
      System.out.println("second");
      break;
    default:
      System.out.println("none");
  }
}

According to the investigation, when enum type is taken as an argument of switch statement, it seems that the value given to case must be a constant. In other words, the description HogeType. is no longer necessary.

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