Test program that shows that NSString can do '\0' characters, however NSLog will terminate its entire output at encountering the first one:

NSStringCanDoNullsButNSLogCant.m

#import <Foundation/Foundation.h>

int main(int argc, char *argv[]) {
	@autoreleasepool {
		NSString	*str = [[NSString alloc] initWithBytes: "\0\r" length: 2 encoding: NSASCIIStringEncoding];
		NSLog(@"len = %zu \"%@\"", str.length, str);
	}
}

Output.txt

2015-08-28 16:48:07.729 Untitled[4116:2242682] len = 2 "