If statement produces a null result in Java

Question

I don't want to add all of the code as it is a game i am making currently. Anyways, I declared class_Selection, and Characterclass. The user enters a string for class_Selection. It displays the result and then proceeds into an if statement in which it uses that same input to decide on what to do afterwards. I am very new to java, and coding for that matter and this is my first project. The problem is probably simple. As you can see I placed it in all caps because I heard that if its in all caps no matter how the user enters it, it will accept that key, such as: MeLeE, That may not be true. The result produces as it goes through the rest of the program correctly even displays the results for class_Selection but when it gets to the if- statements it displays null.

Edit The problem is somehow character class is equal to null so when I System.out.println(Characterclass); I am receiving null.

I fixed the ==, thank you for that, but I need to fix CharacterClass somehow ending up to be null.

EDIT The problem was, in the IF-statement I had the answer in all caps, I know there is probably a way to do that, but I wasn't doing it right. If I enter the right key such as if it is MELEE, I enter MELEE it will display the results. Also I think when I did the system.out.println(Characterclass); , I didn't have a method that ran it so I am going to fix that. I got it to display the bonuses.

Thank you for the == problem, I am a step farther on my goal.

// Class Selection

    System.out.println("Which one did you excel in ( Class )? Melee, Magic, or Archery?"); // Class selection
    String class_Selection; // Hold the class name (make method with this to declare bonuses and things that have to do with the class he chose: such as If ( class_Selection == melee) 
    class_Selection = classSelection.next(); // User enters name of class they want
    System.out.println("You entered: " + class_Selection + (" Is this the class you want?, y or n?"));

    String yOrN;
    yOrN = defaultScanner.next();

    if (yOrN == "n") { // redo if selection is no
        System.out.println("Then which class would you like? Melee, Magic, Archery?");
        class_Selection = classSelection.next();
        System.out.println("You entered: " + class_Selection + (" Is this the class you want?, y or n?"));
        yOrN = defaultScanner.next();


    }else{ // Does nothing if y because the selection is correct
    }

    // Continue after class selection


        System.out.println("Your class is: " + class_Selection); // Final display
        System.out.println("\n");


        // This is where your selection takes effect and displays your bonuses

        if (class_Selection == "MELEE") {
            Characterclass = "melee";
            System.out.println("Melee = +5 Blade, +5 Blunt, +5 Hand-To-Hand, +5 Heavy Armor,");

        }
        if (class_Selection == "ARCHERY") {
            Characterclass = "Archery";
            System.out.println("+10 Archery, + 10 Light Armor");

        }
        if (class_Selection == "MAGIC") {
            Characterclass = "Magic";
            System.out.println(" +10 Arcane, +5 Light Armor");


}
        System.out.println(Characterclass);

}

}

I don't think your CharacterClass is defined in the scope of the print statement — recursion.ninja, Apr 14 '13 at 17:50
This kind of questions (`==` instead of `equals`) is asked at least 20 times a day. — Maroun, Apr 14 '13 at 17:52
Why don't you use an enum for your classes (not a must, just a suggestion)? — Menno, Apr 14 '13 at 17:53
Efficient debugging is the second most valuable skill two a programmer, second only to initially writing correct & clean code. — recursion.ninja, Apr 14 '13 at 17:55
Tried fixing Characterclass in the scope as you said awash, but its still producing null even with the == fix. — user2280146, Apr 14 '13 at 18:13

score 2 · Answer 1 · answered Apr 14 '13 at 17:50

2

if (yOrN == "n")!!! should be if (yOrN.equals("n")){...}

For any Object equality check, you should use Object#equals. For Object reference equality check you should use ==

answered Apr 14 '13 at 17:50

Subhrajyoti Majumder

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Produces same results, did this to all of the strings in the if statement. – user2280146 Apr 14 '13 at 17:53
Thank you for that, but that wasn't the problem, just a problem lol. Can you read my edit please? – user2280146 Apr 14 '13 at 18:11
`System.out.println(Characterclass);` here what is `Characterclass`??? – Subhrajyoti Majumder Apr 14 '13 at 18:17
Sorry I fixed it, and it was declared in an area I didn't paste. Thank you for your help. – user2280146 Apr 14 '13 at 18:20

blackpanther · Answer 2 · 2013-04-28T10:47:53.087

2

Comparing Strings in Java, use String.equals(); not == operator. e.g. yOrN.equals("n")

The == operator checks to see if the two Strings reference the same String object. The equals() method compares if two Strings have the same characters within both Strings.

edited Apr 28 '13 at 10:47

answered Apr 14 '13 at 17:50

blackpanther

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AllTooSir · Answer 3 · 2013-04-14T17:57:37.607

0

Compare Strings using .equals(), not using == which compares references. If you want a case insensitive comparison use .equalsIgnoreCase()

edited Apr 14 '13 at 17:57

answered Apr 14 '13 at 17:52

AllTooSir

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score 0 · Answer 4 · answered Apr 14 '13 at 17:53

0

Comparison of Strings should be done using equals

if (yOrN == "n") {
// Code
}

Will become

if (yOrN.equlals("n")) {
// Code
}

answered Apr 14 '13 at 17:53

Amarnath

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score 0 · Answer 5 · edited May 23 '17 at 10:25

0

Use:

if (yOrN.equals("n"))

Read this about how to compare Strings.

edited May 23 '17 at 10:25

Community

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answered Apr 14 '13 at 17:54

joan

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If statement produces a null result in Java

5 Answers5