Allocating and Returning Objects from Methods

[Ahmed Al H]

i didn't get why you didn't need to allocate and initialize resultFraction is it a different style or is it a must if the return type is an object and if you can give me a simple example because i am stuck in chapter 7 since december. another question why was 3/4 printed twice i can see only one print method being invoked.

Thank you

[kefka]

Hi Ahmed,

I don't have an answer to your question regarding the non allocation and initialization of resultFraction. I just wanted to ask you if your code is also printing the 3/4 twice? In my code its only once but in the book its twice.  Maybe someone else could explain this?

Daniel

[kefka]

Also regarding your first question I was thinking and researching maybe the explanation is that aFraction and bFraction both get their instance variables changed here:

Code: (Objective-C)

[aFraction setTo:1 over:4];//Set first fraction to 1/4
[bFraction setTo:1 over:2];//Set the second one to 1/2

However, resultFraction just gets completely replaced with another one(as below), so I think it is not necessary to allocate memory or initialize it.

Code: (Objective-C)

resultFraction = [aFraction add:bFraction];

You might find the below link to stack overflow.com useful!

Regards

Daniel

http://stackoverflow.com/questions/3801156/when-not-to-alloc-and-init-an-nsstring

[kefka]

Of course it could also be the fact that......

Code: (Objective-C)

Fraction *result = [[Fraction alloc]init];

.......is included in the method implementation?...seems more likely.

Daniel

[Ahmed Al H]

Hi Ahmed,

I don't have an answer to your question regarding the non allocation and initialization of resultFraction. I just wanted to ask you if your code is also printing the 3/4 twice? In my code its only once but in the book its twice.  Maybe someone else could explain this?

Daniel

it prints once