Thread: the Try keyword in visual basic, how so in c?

I'm porting some code of a game I found on the web to C. It was written in Visual Basic 2005.

It goes a little something like..

Code:

Try
    Do
     'code block
    Loop Until Not Change
Catch ex As Exception
    Throw New Exception("invalid move")
End Try

what would I do in C...

Code:

do {
 /*
  more do, break, etc
 */
} while (!change);

I have an idea of what it does, but I have no idea of how to logically do such in C, let alone understand how it affects other routines that call a routine containing said code, etc.

in another routine of the game, it simply has

Code:

'---if possible value is string.Empty, then error---
        If str = String.Empty Then
            Throw New Exception("Invalid Move")
        End If

Can anyone explain please?

C does not have built-in exception handling. For that you'll have to look at using Microsoft's Exception Handling API.

The C standard library uses errno for most major error handling, as well as relying on return values from functions.

You don't really need exceptions in the VB sense in C....

Code:

char *szInput = readstring(); /* some user defined function to read a string */
if(szInput)
{
    /* It worked. */
}
else
{
    /* Failed */
}

Usually that's done via errno in the C standard library.

Code:

#include <stdio.h>

int main(void)
{
	FILE *f = fopen("123","r");
	if(f)
	{
		fclose(f);
	}
	else
	{
		perror("Unable to open file.");
	}
	return 0;
}

perror() prints an error message associated with the error that errno signifies. For example, this is the output I received:

Code:

Unable to open file.: No such file or directory

Originally Posted by kky2k

how about assert(); guyz...

No, http://www.acm.uiuc.edu/webmonkeys/b...guide/2.1.html