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?
311 Answers
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];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; }
}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.
0public 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"); } }
}Define enum:
public enum Gesture
{ ROCK, PAPER, SCISSORS;
}Define a method to check enum content:
private boolean enumContainsValue(String value)
{ for (Gesture gesture : Gesture.values()) { if (gesture.name().equals(value)) { return true; } } return false;
}And use it:
String gestureString = "PAPER";
if (enumContainsValue(gestureString))
{ Gesture gestureId = Gesture.valueOf(gestureString); switch (gestureId) { case ROCK: Log.i("TAG", "ROCK"); break; case PAPER: Log.i("TAG", "PAPER"); break; case SCISSORS: Log.i("TAG", "SCISSORS"); break; }
}You can do it in a simpler way , like the below:
boolean IsEqualStringandEnum (String str,Enum enum)
{ if (str.equals(enum.toString())) return true; else return false;
}This is my solution in java 8:
public static Boolean isValidCity(String cityCode) { return Arrays.stream(CITY_ENUM.values()) .map(CITY_ENUM::getCityCode) .anyMatch(cityCode::equals); }This seems to be clean.
public enum Plane{
/** * BOEING_747 plane. */
BOEING_747("BOEING_747"),
/** * AIRBUS_A380 Plane. */
AIRBUS_A380("AIRBUS_A380"),
;
private final String plane;
private Plane(final String plane) { this.plane= plane;
}
Plane(){ plane=null;
}
/** * toString method. * * @return Value of this Enum as String. */
@Override
public String toString(){ return plane;
}
/** * This method add support to compare Strings with the equalsIgnoreCase String method. * * Replicated functionality of the equalsIgnorecase of the java.lang.String.class * * @param value String to test. * @return True if equal otherwise false. */
public boolean equalsIgnoreCase(final String value){ return plane.equalsIgnoreCase(value);
}And then in main code:
String airplane="BOEING_747";
if(Plane.BOEING_747.equalsIgnoreCase(airplane)){ //code
}Doing an static import of the GestureTypes and then using the valuesOf() method could make it look much cleaner:
enum GestureTypes{ROCK,PAPER,SCISSORS};and
import static com.example.GestureTypes.*;
public class GestureFactory { public static Gesture getInstance(final String gesture) { if (ROCK == valueOf(gesture)) //do somthing if (PAPER == valueOf(gesture)) //do somthing }
}You can compare a string to an enum item as follow,
public class Main { enum IaaSProvider{ aws, microsoft, google } public static void main(String[] args){ IaaSProvider iaaSProvider = IaaSProvider.google; if("google".equals(iaaSProvider.toString())){ System.out.println("The provider is google"); } }
}You can use equals().
enum.equals(String)
