Cocos2d Random object from array not being called

Question

I have created an array which stores either red, yellow, or green (3, 2, or 1) based on what the user hits. I want the code to choose a random number in the array and display the corresponding color on the screen. However, when the code runs, the program always chooses the last entered color and only shows that color. Code:

-(void)CreateEnemy:(ccTime)dt{
CCSprite *Enemy;
int a;
if (colorArray != nil) {
    a = arc4random()% [colorArray count];
}
int y = [[colorArray objectAtIndex:a] integerValue];
if (y == 1) {
    Enemy = [CCSprite spriteWithFile:@"GreenBall.png"];
    int x = arc4random()%320;
    Enemy.position = ccp(x, 530);
    id action = [CCMoveTo actionWithDuration:3 position:ccp(x, -30)];
    [Enemy runAction:[CCSequence actions:action, [CCCallFuncN actionWithTarget:self selector:@selector(spriteMoveFinished:)], nil]];
    [enemyArray addObject:Enemy];
    [self addChild:Enemy z:2 tag:1];
    NSLog(@"Green Enemy Attack!!");
}
else if (y == 2) {
    Enemy = [CCSprite spriteWithFile:@"YellowBall.png"];
    int x = arc4random()%320;
    Enemy.position = ccp(x, 530);
    id action = [CCMoveTo actionWithDuration:3 position:ccp(x, -30)];
    [Enemy runAction:[CCSequence actions:action, [CCCallFuncN actionWithTarget:self selector:@selector(spriteMoveFinished:)], nil]];
    [enemyArray addObject:Enemy];
    [self addChild:Enemy z:2 tag:1];
    NSLog(@"Yellow Enemy Attack!!");
}
else if (y == 3) {
    Enemy = [CCSprite spriteWithFile:@"RedBall.png"];
    int x = arc4random()%320;
    Enemy.position = ccp(x, 530);
    id action = [CCMoveTo actionWithDuration:3 position:ccp(x, -30)];
    [Enemy runAction:[CCSequence actions:action, [CCCallFuncN actionWithTarget:self selector:@selector(spriteMoveFinished:)], nil]];
    [enemyArray addObject:Enemy];
    [self addChild:Enemy z:2 tag:1];
    NSLog(@"Red Enemy Attack!!");
}
}

Y should be a randomly chosen color, but it never is.

The amount of inputs that the person, well inputted. I put in 5 different inputs, and it only showed the last one I inputted — chandhooguy, Dec 25 '12 at 17:18
well, the question is: are you sure that `[colorArray count]` has the value you expect it to have? could you put an NSLog trace there? — sergio, Dec 25 '12 at 17:22
Hmmm, good call, let me try logging all of the different objects in it. — chandhooguy, Dec 25 '12 at 17:22
ok, then it makes sense, arc4random will always give you 0... if you don't mind, I will add this finding as an answer... — sergio, Dec 25 '12 at 17:37

score 1 · Accepted Answer · answered Dec 25 '12 at 17:39

1

In:

if (colorArray != nil) {
   a = arc4random()% [colorArray count];
}
int y = [[colorArray objectAtIndex:a] integerValue];

what is most likely happening is that [colorArray count] has not the value you expect it to have, so that arc4random only returns 0 (or a limited set of values).

If you add an NSLog trace just before calculating the value for a, you can assess the value for [colorArray count].

answered Dec 25 '12 at 17:39

sergio

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Yep! Fixed it; Turns out my NSMutableArray, which was in another class, was not allocated/initialized, so every time I went to a different view, the array would reset itself. Thanks!!! – chandhooguy Dec 25 '12 at 17:46

Cocos2d Random object from array not being called

1 Answers1