A C string is just like in C.
char myCString[] = "test";
An NSString uses the @
character:
NSString *myNSString = @"test";
If you need to manage the NSString’s memory:
NSString *myNSString = [NSString stringWithFormat:@"test"];
NSString *myRetainedNSString = [[NSString alloc] initWithFormat:@"test"];
Or if you need an editable string:
NSMutableString *myMutableString = [NSMutableString stringWithFormat:@"test"];
You can read more from the Apple NSString documentation.