Releasing of strings

I got a doubt that when should the st开发者_JAVA技巧rings are released.I am not made any allocation to the string is there any necessary to release the string?

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No if you do not "allocate" the string they are auto released. for example

NSString *aTestString = [NSString stringWithFormat:@"Hello %@",@"World"];

This string is auto released, so you do not have to call [aTestString release];

If you would do:

NSString *aTestString = [[NSString alloc] initWithFormat:@"Hello %@",@"World"];

Then you would need to release it by [aTestString release]; because you manually allocated. Therefore it is wise to autorelease it, so you do not have to think of it later on

NSString *aTestString = [[[NSString alloc] initWithFormat:@"Hello %@",@"World"] autorelease];

But that would just be the same as the first piece of code I gave ya. Back to the point, no you do not have to manually release it as long as you do not allocate it yourself.

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Did you create the string via a call to alloc, new, or a method containing copy? Did you explicitly retain the string yourself? If you got the NSString from a CFStringRef, did you create the CFStringRef with a function that included create? If not, you don't have to do anything. If you did, you have to either release or autorelease the string.

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Object allocation/deallocation rules

You need to call [Object release] if and only if:

• You called [Object alloc]
• You called [Object retain]
• You called [Object new]

If you did not explicitly allocate or retain the object, then you need to release it. If you got the object via a class method, the method did something like this: return [[[Object alloc] init] autorelease];. This allocates a new object, but is autoreleased when the NSAutoReleasePool next gets a chance.