Hello guys,

I found this solution to exercise 13.4:


  

  Fraction *add(Fraction *array[], int lenght)    
    {    
        Fraction *result = [[Fraction alloc] init];    
        [result setTo:0 over:1];    
        Fraction *temp;    
           
        for(int i=0; i<15;++i)   
        {    
            temp = [result add: array[i]];    
            [result release];    
            result = temp;    
        }  
            
        return result;    
    }   

It works but...   ... I would like someone please explain to me:

1) why you need to use a variable "temp" instead of incrementing directly "result" ;
2) why "temp" is of the same (Fraction *) type as "result" but you do not have to write the [[Fraction alloc] init] part for it as you do fot the "result". I have a VB/C# background, just started with Objective-c.

NOTE: I am using XCode 4.3 and I have NOT ENABLED ARC because I want to get used to manage the memeory by myself.

In fact the **not right working** code I wrote before I browsed for the solution was:


 

   Fraction *add(Fraction *array[], int lenght)    
    {    
        Fraction *result = [[Fraction alloc] init];    
        [result setTo:0 over:1];    
           
        for(int i=0; i<15;++i)   
        {      
            result = [result add: array[i]];    
        }    
            
        return result;    
    }    

This would have worked in C#, without the need of the "temp".

Thanks

Nicola