Memory management with C array in Objective C

Question

I have a c style array used in objective c .m file:

Gift gifts[3];

And Gift is a struct defined as this:

typedef struct {
    NSString *name;
    CCSprite *sprite;
}Gift;

This is how I use the array

for (int i=0; i<3; i++) {
    gifts[i].name = [[NSString stringWithFormat:@"Reward%d_%@.png", i+1, location] retain];
    gifts[i].sprite = [CCSprite spriteWithSpriteFrameName:gifts[i].name];
    CGPoint pos = [[GameConfigure sharedManager] getCoordinateforKey:@"REWARD_ITEM"];
    gifts[i].sprite.position = ccp(pos.x+i*238, pos.y);
    [rewardLayer addChild:gifts[i].sprite z:1 tag:100+i];
}

How do I manage the memory?
Do I need to free the C array?

Seems to be a duplicate to stackoverflow.com/questions/9869883/… — ZhangChn
– ZhangChn, Commented May 9, 2012 at 8:31

trojanfoe · Accepted Answer · 2012-05-09 07:54:09Z

0

There is no need to free the array, as you don't allocate it.

Are you sure that spriteWithSpriteFrameName doesn't return an autoreleased object (its naming convention suggests it does)?

answered May 9, 2012 at 7:54

trojanfoe

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2 Comments

DragonDoingPragramming Over a year ago

spriteWithSpriteFrameName returns an autorelease object. Does this matter?

trojanfoe Over a year ago

@DragonDoingPragramming Yes, it matters - just as you have done with the NSString, you need to retain it.

adali · Accepted Answer · 2012-05-09 08:12:29Z

0

you don't have to free C array , but you should manage the Object in the C array

in your code

for (int i=0; i<3; i++) {

    //retain is good, but if you don't release it at the end ,  it leaks!!!!
    gifts[i].name = [[NSString stringWithFormat:@"Reward%d_%@.png", i+1, location] retain];

    //here is not a good idea, why you don't retian here?  it will be autorelease 
    gifts[i].sprite = [CCSprite spriteWithSpriteFrameName:gifts[i].name];

    CGPoint pos = [[GameConfigure sharedManager] getCoordinateforKey:@"REWARD_ITEM"];
    gifts[i].sprite.position = ccp(pos.x+i*238, pos.y);
    [rewardLayer addChild:gifts[i].sprite z:1 tag:100+i];
}

you'd better create a NSObject instead of the struct GIFT

use Property of the member

@interface GIFT : NSObject
{
    NSString *name;
    CCSprite *sprite;
}

@property (nonatomic, retain) NSString *name;
@property (nonatomic, retain) CCSprite *sprite;

@end

and use NSArray instead of C Array

NSArray *gifts = [NSArray arrayWithObjects:
                                         [[[GIFT alloc] init] autorelease],
                                         [[[GIFT alloc] init] autorelease],
                                         [[[GIFT alloc] init] autorelease],
                                         nil];

but if you still want to use C array, try to manage the reference count in the struct of your GIFT

edited May 9, 2012 at 8:12

answered May 9, 2012 at 8:07

adali

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4 Comments

DragonDoingPragramming Over a year ago

@interface GIFT : NSObject { NSString *name; CCSprite *sprite; } I have never seen this kind of implementation, can thou explain a bit?

adali Over a year ago

eeee..., what means you have never seen? it's the definition of a Object in Objective-C just like NSString and CCSprite and etc..

DragonDoingPragramming Over a year ago

Hmm... Yeap :) I could not recognize it, haha

adali Over a year ago

check this, it's so basic. :) nicolaslarrea.blogspot.com/2011/05/creating-custom-object.html

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