Assigning variables to array not working correctly (Java)

Question

For some reason only the final values in the array are assigned values...why is this?

public void openFrameScores() {
    int x = 0;
    int y = 0;
    int total = 0;

    for(int i = 0; i < framesToBowl; i++) {
        scores = new int[2][framesToBowl];
        x = (int)(Math.random() * 9);
        if(x == 0) y = (int)(Math.random() * 9);
        else y = (int)(Math.random() * (9 - x));
        scores[0][i] = x;
        scores[1][i] = y;
    }

    for(int i = 0; i < framesToBowl; i++) {
        total = total + scores[0][i] + scores[1][i];
        System.out.println("Frame: " + i + ", ball 1 = " + scores[0][i] +
        ", ball 2 = " + scores[1][i] + ", total score = " + total);
    }

}



------------------------------------------------

Frame: 0, ball 1 = 0, ball 2 = 0, total score = 0  
Frame: 1, ball 1 = 0, ball 2 = 0, total score = 0  
Frame: 2, ball 1 = 0, ball 2 = 0, total score = 0  
Frame: 3, ball 1 = 0, ball 2 = 0, total score = 0  
Frame: 4, ball 1 = 0, ball 2 = 0, total score = 0  
Frame: 5, ball 1 = 0, ball 2 = 0, total score = 0  
Frame: 6, ball 1 = 0, ball 2 = 0, total score = 0  
Frame: 7, ball 1 = 0, ball 2 = 0, total score = 0  
Frame: 8, ball 1 = 0, ball 2 = 0, total score = 0  
Frame: 9, ball 1 = 6, ball 2 = 1, total score = 7

i too am having the same problem

Dylansq
– Dylansq

2012-10-23 05:30:46 +00:00
Commented Oct 23, 2012 at 5:30 — Dylansq
– Dylansq, Commented Oct 23, 2012 at 5:30

leo · Accepted Answer · 2012-10-23 05:34:41Z

7

Because at each iteration you're redeclaring the array.

for(int i = 0; i < framesToBowl; i++) {
        scores = new int[2][framesToBowl];   // Here!!!

At each iteration you say that scores receives a new, fully zeroed vector. That's why you can only see the value of the last iteration.

You can solve this problem by taking the initialization of scores outside of the loop.

scores = new int[2][framesToBowl];
for(int i = 0; i < framesToBowl; i++) {
    x = (int)(Math.random() * 9);
    if(x == 0) y = (int)(Math.random() * 9);
    else y = (int)(Math.random() * (9 - x));
    scores[0][i] = x;
    scores[1][i] = y;
}

edited Oct 23, 2012 at 5:34

answered Oct 23, 2012 at 5:30

leo

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1 Comment

jlordo Over a year ago

fix it by taking scores = new int[2][framesToBowl]; out of the loop

legendofawesomeness · Accepted Answer · 2012-10-23 05:32:03Z

0

Take out the array initialization from the for loop.

public void openFrameScores() {
    int x = 0;
    int y = 0;
    int total = 0;
scores = new int[2][framesToBowl];
    for(int i = 0; i < framesToBowl; i++) {

        x = (int)(Math.random() * 9);
        if(x == 0) y = (int)(Math.random() * 9);
        else y = (int)(Math.random() * (9 - x));
        scores[0][i] = x;
        scores[1][i] = y;
    }

    for(int i = 0; i < framesToBowl; i++) {
        total = total + scores[0][i] + scores[1][i];
        System.out.println("Frame: " + i + ", ball 1 = " + scores[0][i] +
        ", ball 2 = " + scores[1][i] + ", total score = " + total);
    }

}

answered Oct 23, 2012 at 5:32

legendofawesomeness

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Comments

TyrZaraki · Accepted Answer · 2012-10-23 05:33:17Z

0

You reset your array at the beginning of the loop.

scores = new int[2][framesToBowl];

This keeps resetting the scores array. So when you go and read it at the bottom only the last instance of it is called.

Just declare it outside the for loop and that should fix your problem.

answered Oct 23, 2012 at 5:33

TyrZaraki

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