Question

I have a really weird problem. Basically just convert a char to nsstring and store them in an nsmutable array.

But the code runs ok on simulator, but crash on device.

Here is the crash code,

char t = 'A' + i;
NSString* alphabetString = [NSString stringWithUTF8String:&t]; //substringToIndex:1];
[tempArray addObject:alphabetString];

Basically the stringWithUTF8String will return NULL on device, but return valid value on simulator.

The device is an iPhone 4s. 

I did not see any notification of changes on NSString stringwithutf8string on iOS5 release.

 Thanks.

Answer 1

The address of a single char is not a C-style string. You need to ensure it’s null terminated with something like:

char t = 'A' + i;
char s[2]; s[0] = t; s[1] = '\0';
NSString* alphabetString = [NSString stringWithUTF8String:s];

From the docpage:

Parameters
     bytes : A NULL-terminated C array of bytes in UTF8 encoding.