stringByAppendingString issues in objective c

Question

NSString *tmpStr = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
xmlSms = [xmlSms stringByAppendingString:tmpStr];
NSLog(xmlSms);

I got code above but NSLog doesn't show anything... Anybody know the problem??

Answer 1

nevermind... i figured out why. The problem is, when you want to use stringByAppendingString on a string, the string should have initial value.

Wrong example:

NSString *str1;
str1 = [str1 stringByAppendingString:@"test"];

Should be:

NSString *str1 = @"";
str1 = [str1 stringByAppendingString:@"test"];