concatenating strings

Question

NSMutableArray * oneText = [[NSMutableArray alloc] init];
[oneText addObject:[arraySystem objectAtIndex:[countImage intValue]]];
[oneText addObject:@".png"];
NSString *oneTextText=[oneText objectAtIndex:0];
[oneTextText stringByAppendingString:[oneText objectAtIndex:1]];
NSLog(oneTextText);

Why can't the above code print 'Lenght.png'? as [arraySystem objectAtIndex:[countImage intValue]] is equal to 'Lenght' it prints only 'Lenght'

Answer 1

put a "oneTextText=" when calling stringByAppendingString, it should be:

oneTextText = [oneTextText stringByAppendingString:[oneText objectAtIndex:1]];