What's the proper way to compare a String to an enum value?

Homework: Rock Paper Scissors game.

I've created an enumeration:

      enum Gesture{ROCK,PAPER,SCISSORS};

from which I want to compare values to decide who wins--computer or human. Setting the values works just fine, and the comparisons work properly (paper covers rock, rock crushes scissors, scissors cuts paper). However, I cannot get my tie to work. The user is declared as the winner any time there's a tie.

Ahhh...crap...this will clarify: userPick is a String with values rock, paper, or scissors. I'm unable to use == to compare userPick to computerPick, which, as you can see below, is cast as type Gesture from my enum.

      if(computer == 1)
         computerPick = Gesture.ROCK;
      else
         if(computer == 2)
           computerPick = Gesture.PAPER;
         else
           computerPick = Gesture.SCISSORS;
      if(userPick.equals(computerPick))
       {
          msg = "tie";
          ++tieGames;
       }
           etc....

I am guessing that there's an issue with rock not being equal to ROCK, or the String userPick not being able to match Gesture computerPick because the latter isn't a String. However, I'm not able to find an example of a similar circumstance in my textbook or Oracle's Java Tutorials, so I'm not sure how to correct the problem...

Any hints?

Solution 1:

I'm gathering from your question that userPick is a String value. You can compare it like this:

if (userPick.equalsIgnoreCase(computerPick.name())) . . .

As an aside, if you are guaranteed that computer is always one of the values 1, 2, or 3 (and nothing else), you can convert it to a Gesture enum with:

Gesture computerPick = Gesture.values()[computer - 1];

Solution 2:

You should declare toString() and valueOf() method in enum.

 import java.io.Serializable;

public enum Gesture implements Serializable {
    ROCK,PAPER,SCISSORS;

    public String toString(){
        switch(this){
        case ROCK :
            return "Rock";
        case PAPER :
            return "Paper";
        case SCISSORS :
            return "Scissors";
        }
        return null;
    }

    public static Gesture valueOf(Class<Gesture> enumType, String value){
        if(value.equalsIgnoreCase(ROCK.toString()))
            return Gesture.ROCK;
        else if(value.equalsIgnoreCase(PAPER.toString()))
            return Gesture.PAPER;
        else if(value.equalsIgnoreCase(SCISSORS.toString()))
            return Gesture.SCISSORS;
        else
            return null;
    }
}

Solution 3:

My idea:

public enum SomeKindOfEnum{
    ENUM_NAME("initialValue");

    private String value;

    SomeKindOfEnum(String value){
        this.value = value;
    }

    public boolean equalValue(String passedValue){
        return this.value.equals(passedValue);
    }
}

And if u want to check Value u write:

SomeKindOfEnum.ENUM_NAME.equalValue("initialValue")

Kinda looks nice for me :). Maybe somebody will find it useful.

Solution 4:

public class Main {

    enum Vehical{
        Car,
        Bus,
        Van
    }

    public static void main(String[] args){

      String vehicalType = "CAR";

        if(vehicalType.equals(Vehical.Car.name())){
            System.out.println("The provider is Car");
        }

     String vehical_Type = "BUS";

       if(vehical_Type.equals(Vehical.Bus.toString())){
            System.out.println("The provider is Bus");
        }


    }
}