C++ to C# (checksum)

Puneet Gupta

Can anyone convert this C++ code to C#

#include
unsigned char calc_checksum(const char *s)
{
unsigned char result;
result = 0;
s++; // Skip dollar sign
while ((*s != '*') && (*s != '\0'))
result ^= *s++;
return result;
}
int main()
{
unsigned char checksum;
checksum = calc_checksum
("$GPRMC,235947.000,V,0000.0000,N,00000.0000,E,,,041299,,*");
printf("Checksum = %02X\n", checksum);
return 0;
}

I want same output in C# as i am getting in this c++ code. Please reply soon, Its very urgent.

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes13y ago
Accepted answer
Here's a C# version which doesn't use unsafe code, though the result is the same:

using System;

class Program
{
static void Main()
{
string s = "$GPRMC,235947.000,V,0000.0000,N,00000.0000,E,,,041299,,*";
byte checksum = calc_checksum(s);
Console.WriteLine("Checksum = {0:X2}", checksum);
Console.ReadKey();
}

static byte calc_checksum(string s)
{
int result = 0;
s = s.Substring(1); // skip dollar sign
foreach(char c in s)
{
if (c == '*') break;
result ^= (int)c;
}
return (byte)result;
}
}
0
Puneet Gupta13y ago
@vulpes : Thank you very much for solution...

Thanks,
Puneet Gupta
0
Vulpes13y ago
The following gives the same output:

Checksum = 1D

as the C++ version.

You'll need to compile with the /unsafe switch or 'use unsafe code' if building from VS:

using System;

unsafe class Program
{
static void Main()
{
string str = "$GPRMC,235947.000,V,0000.0000,N,00000.0000,E,,,041299,,*";
fixed(char *cp = str)
{
char *s = cp;
byte checksum = calc_checksum(s);
Console.WriteLine("Checksum = {0:X2}", checksum);
}
Console.ReadKey();
}

static byte calc_checksum(char* s)
{
int result = 0;
s++; // skip dollar sign
while ((*s != '*') && (*s != '\0'))
result ^= *s++;
return (byte)result;
}
}
0