In Java, I'm nesting for loops, but it's giving me an error message

Question

I tried a practice for loop with the EXACT same format, and it won't result in an error message like this one does. And the inner loop (with int i) worked perfectly before I introduced the outer loop (with int j):

private static void mBTI(){
    Scanner console = new Scanner(System.in);
    Random rand = new Random();

    //Practice loop
    int wtf = console.nextInt();
    for (int k = 1; k <= wtf; k++){
        for (int m = 1; m <= 2; m++){
            System.out.println("derp");
        }
    }        

    //Error loop
    System.out.println("How many results do you want? (Type a numerical value.)");
    int amount = console.nextInt();
    String[] types = {"E","I","N","S","F","T","J","P"};
    int loop = 0;
    for(int j = 1; j <= amount; j++){
        for(int i = 1; i <= 4; i++){
            int randType = rand.nextInt(2);
            randType = loop+randType;
            System.out.print(types[randType]);
            loop = loop+2;
        }
        System.out.println("");
    }
}

So ... what's the error message? What line does it reference? We are currently unable to read your mind. — Andy Thomas, Jun 15 '17 at 07:33
from my opinion it fail on `System.out.print(types[randType]);` with `array index out of bounds exception` — degr, Jun 15 '17 at 07:35
The basic error message it gives me is: java.lang.ArrayIndexOutOfBoundsException: 9 — Ray25Lee, Jun 15 '17 at 07:35
Looks like an OutOfBounds Exception. If you enter a big number for `amount` then `randType` is going to get big — Scary Wombat, Jun 15 '17 at 07:35
AH! I see it; I'm not knocking "loop" back down to 0. Thank you, Scary Wombat. — Ray25Lee, Jun 15 '17 at 07:37

score -1 · Answer 1 · answered Jun 15 '17 at 07:38

-1

You are probably gettin an index out of bounds exception. make sure to use randType = randType % types.length (or something else to keep randType in bounds).

answered Jun 15 '17 at 07:38

PLEXATIC

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In Java, I'm nesting for loops, but it's giving me an error message

1 Answers1