Memory management in appending a string? - iphone

Question

I have an iPhone application in which i am creating an array in the didfinishlaunch in the appdelegate. Like this:
for(int i=1;i<53;i++)
{
NSString *namestring=[NSString stringWithString:#"avatar"];
NSString *string = [NSString stringWithFormat:#"%d",i];
NSString *pngstring=[NSString stringWithString:#".png"];
string = [string stringByAppendingString:pngstring];
namestring = [namestring stringByAppendingString:string];
NSLog(#"%#",namestring);
[avtararray addObject:namestring];
}
working fine.and everywhere i am doing the avatar job with my avatararray in the appdelegate.But in one case when i pop back to the previous view and try to load the string from the array again
NSString *avatarstringt=[[appDelegate.avtararray objectAtIndex:i]description];here it is crashing with a an error
-[CFString description]: message sent to deallocated instance..
when doing the profile job i know that the leak is in the above loop in the appendingstring code.Can anybody help me to remove this?

Answer 1

First of all, Never do this
NSString *string = [NSString stringWithFormat:#"%d",i];
NSString *pngstring=[NSString stringWithString:#".png"];
string = [string stringByAppendingString:pngstring];
The following statements, are redundant
NSString *namestring=[NSString stringWithString:#"avatar"];
NSString *pngstring=[NSString stringWithString:#".png"];
and should be written as:
NSString *namestring=#"avatar";
NSString *pngstring=#".png";
You can use as :
NSString *namestring=#"avatar";
NSString *numberString = [NSString stringWithFormat:#"%d",i];
NSString *pngstring=#"png";
namestring = [namestring stringByAppendingFormat:#"%#.%#",numberString,pngstring];
Even the shortest of code :
for(NSInteger i=1;i<5;i++){
NSString *namestring = [NSString stringWithFormat:#"avatar%#.png",#(i)];
NSLog(#"%#",namestring);
}
As suggested by rmaddy: you can use i as integer, no need of converting it into nsnumber
NSString *namestring = [NSString stringWithFormat:#"avatar%d.png",i];