releasing object after return

Question

Hi,

I use an object to get some values with it and return this values. The values which will be returned are still in this object. Heres the code:

    XMLErrorParser *xmlErrorParser = [XMLErrorParser alloc];
    [xmlErrorParser parseData: data];
    return xmlErrorParser.errors;

So how can i release the xmlErrorParser Object and return the values of it? Thanks.

Answer 1

That's what autorelease is for (could it be that you forgot init?):

XMLErrorParser *xmlErrorParser = [[[XMLErrorParser alloc] init] autorelease];
[xmlErrorParser parseData: data];
return xmlErrorParser.errors;

Read the Memory Management Guide for Cocoa.

---

Depending on the purpose of your method, you might have to retain xmlErrorParser.errors as well.

Answer 2

XMLErrorParser *xmlErrorParser = [[XMLErrorParser alloc] init];
[xmlErrorParser parseData: data];
return [xmlErrorParser autorelease].errors;

or better

XMLErrorParser *xmlErrorParser = [[[XMLErrorParser alloc] init] autorelease];
[xmlErrorParser parseData: data];
return xmlErrorParser.errors;

Answer 3

I suppose parseData is your initializer, In that case you can use the autorelease message to let the innermost autorelease pool know that you no longer need the object.

Example:

XMLErrorParser *xmlErrorParser = [XMLErrorParser alloc];
[[xmlErrorParser parseData: data] autorelease];
return xmlErrorParser.errors;

I advise you explicitly retain the errors property as well, otherwise you can lose track of it. Rule of thumb, release and autorelease calls together must match the number of retains in order to dealloc an object.

Answer 4

Just return an auto-released version of the object errors holds.

Without giving us more details about what XMLErrorParser is, lets assume that errors holds some NSArray:

XMLErrorParser *xmlErrorParser = [[XMLErrorParser alloc] init];
[xmlErrorParser parseData: data];
NSArray *errors = [[xmlErrorParser.errors retain] autorelease];
[xmlErrorParser release];
return errors;

(Note that you were missing the initialization for the error parser object.)

Answer 5

How about - autorelease?