Question

I have a NSString [WORD] that has some length [LEN]. What i need to do is to get bytes from this string and put them together with length in short (2 bytes), so i would have [WORD] [LEN].
E.g.
String “AB” in utf8 HEX is 4142. Length of this string is 2==> 0002 in HEX.
So everything together is 41420002. How to get this bytes together?

Answer 1

I think this code does what you want.

NSString *myString = @"AB";
const char *chars = [myString UTF8String];

NSMutableString * result = [NSMutableString string];
for (int i=0; i < [myString length]; i++) {
    [result appendFormat:@"%X", chars[i]];
}

[result appendFormat:@"%04X", [myString length]];

NSLog(@"%@", result);

Hope it helps!