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Thread: Answer always false.

  1. #1
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    Default Answer always false.

    Ok, take a look at this:
    import static java.lang.System.out;
    import java.util.*;
     
    public class mainMenu {
    	private static String Choice;
    	private static String Fight;
    	private static String Options;
    	private static String Info;
    	private static String Help;
    	private static String Quit;
    	//private static String choice;
    	private static String fight;
    	private static String options;
    	private static String info ;
    	private static String help;
    	private static String quit;
    	private static String Carrer;
    	private static String carrer;
     
    	public static void main(String[] args){
    		Scanner keyboard = new Scanner(System.in);
     
    		out.println("**************************************");
    		out.println("*  Choice  *          Info.          *");
    		out.println("**************************************");
    		out.println("*  Fight   *   Fight instantly!      *");
    		out.println("*  Carrer  *   Begin your carrer     *");
    		out.println("*  Options *   Coming Soon           *");
    		out.println("*  Info    *   Making of the game.   *");
    		out.println("*  Help    *   Learn how to play.    *");
    		out.println("*  Quit    *   Leave the game.       *");
    		out.println("**************************************");
    		out.println("Pick one:");
    		out.println("");
    		Choice = keyboard.nextLine();
    		out.println("Your choice was " + Choice);
    		if (Choice == Fight || (Choice == fight)) {
     
    		} else if (Choice == Carrer || (Choice == carrer)){
     
    		} else if (Choice == Options || (Choice == options)){
     
    		} else if (Choice == Info || (Choice == info)){
     
    		} else if (Choice == Help || (Choice == help)){
     
    		} else if (Choice == Quit || (Choice == quit)){
    			System.exit(1);
    		} else {
    			out.println("Not a choice.");
    		}
     
    	}
     
    }
    Ok, here is the point of the code, when you type a choice, it will become the 'choice' right? and then as the else if statements read, it will do certain things, (I will add these later) but no matter what I type in it always reads out, "Not a choice." what do I do?


  2. #2
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    Default Re: Answer always false.

    You never set the String "Fight" to anything so it should only go into if statement if Choice happens to be null.

    Actually, none of the other variables are set, so unless choice is null, it'll never be any.

    (On the other hand, if it is null for some odd reason, it will act like you've selected all the choices.

    Also, it's

    System.out.prinltn()

    not

    out.println()

    You don't have any class variables called out, and even if you did, none with a println method.

    Oh, you imported the out variable. You know that by default, all programs import the java.lang package, right?

    (However, if you wish to call that method, you must use System.out.println(), not out.println().)

    Use the .equals(Object) method to compare Objects like Strings.

    Try this:

    import java.util.*;
     
    public class mainMenu {
     
     
     
    	public static void main(String[] args){
    		Scanner keyboard = new Scanner(System.in);
     
                        String choice = "";
    		System.out.println("**************************************");
    		System.out.println("*  Choice  *          Info.          *");
    		System.out.println("**************************************");
    		System.out.println("*  Fight   *   Fight instantly!      *");
    		System.out.println("*  Carrer  *   Begin your carrer     *");
    		System.out.println("*  Options *   Coming Soon           *");
    		System.out.println("*  Info    *   Making of the game.   *");
    		System.out.println("*  Help    *   Learn how to play.    *");
    		System.out.println("*  Quit    *   Leave the game.       *");
    		System.out.println("**************************************");
    		System.out.println("Pick one:");
    		System.out.println("");
    		Choice = keyboard.nextLine();
    		System.out.println("Your choice was " + Choice);
    		if (Choice.equals("Fight") || (Choice.equals("fight")) {
     
    		} else if (Choice.equals("Carrer") || (Choice.equals("carrer"))){
     
    		} else if (Choice.equals("Options")|| (Choice.equals("options"))){
     
    		} else if (Choice.equals("Info") || (Choice.equals("info"))){
     
    		} else if (Choice.equals("Help") || (Choice.equals("help"))){
     
    		} else if (Choice.equals("Quit")|| (Choice.equals("quit"))){
    			System.exit(1);
    		} else {
    			System.out.println("Not a choice.");
    		}
     
    	}
     
    }
    Last edited by javapenguin; October 7th, 2011 at 01:42 AM. Reason: Forgot a ")"

  3. #3
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    Default Re: Answer always false.

    Strings look like this

    String str = "bob";

    It looked like you were trying to use the variable names as the String text. It doesn't work that way. (At least not in Java, C++, or C.)



    String fight = "Fight";
    String career = "Career";

    A String is basically like the text inside your println() methods (actually, that's what's passed to it, though if you use primitives, it will automatically call the toString() of their wrapper classes or maybe it just knows how to convert them to a String (Can't recall which one of those two it was.) If you use non-String objects, it will call the toString() of that class, which often looks like gibberish(or more accurately, like a bunch of addresses and words.)

    As for equals, it's part of the Comparable interface, which String implements. It's used for comparing Objects that implement Comparable.

  4. #4
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    Default Re: Answer always false.

    Just a few tips for you..

    Rather than have multiple String variables written out like:

    	private static String Choice;
    	private static String Fight;
    	private static String Options;
    	private static String Info;
    	private static String Help;
    	private static String Quit;
    	private static String fight;
    	private static String options;
    	private static String info ;
    	private static String help;
    	private static String quit;
    	private static String Carrer;
    	private static String carrer;

    You could do it like this:

    private static String Choice, Flight, Options, Info, Help, Quit, flight, options, info, help, quit, Carrer, carrer;

    Also, instead of checking against 2 different String variables for the possability of a capital letter, you should do:

    		if (Choice.toLowerCase().equals("flight")) {			
     
    		} else if (Choice.toLowerCase().equals("carrer")){
     
    		} else if (Choice.toLowerCase().equals("options")){
    ...

    This way eliminates the need for those String variables. It also allows the user to enter FLIGHT or FlIgHt or any combination and it would still recognise the input.

    This will fix your original issue too..
    Please use [highlight=Java] code [/highlight] tags when posting your code.
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    Default Re: Answer always false.

    Quote Originally Posted by javapenguin
    Also, it's

    System.out.prinltn()

    not

    out.println()
    The original poster is using a static imports, so this is completely valid syntax.

  7. #6
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    Default Re: Answer always false.

    Thanks all, it works great now, I have always had issues with this, so I now can continue on Thanks.

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