Is if(TRUE) a good idea in C?

Question

In the C programming language, it is my understanding that variables can only be defined at the beginning of a code block, and the variable will have the scope of the block it w

Answer 1

I think you're working with some outdated assumptions. I've been coding straight C using GCC for a few months now, and you don't need to declare variables at the beginning of a block, even though the Second edition of K&R says you have to. You can declare your variable anywhere, like like this not-very-useful example:

char* palstring;
palstring = malloc(LARGEST_STRING);
memset(palstring, 0, sizeof palstring);
fgets(palstring, LARGEST_STRING, fin);

char* cur = palstring;
char letter;
letter = *cur;

So there's no need to do what you're suggesting. The language has moved on.

Another good addition to the C language is Variable Length Arrays, which allow you to pass an array to a function along with its size. In the old days, all you could do was pass in a pointer.

Answer 2

You don't even need an if statement. You can create blocks with {}

That should probably be a separate function however.

Example here:

#include <stdio.h>

int
main(int argc, char **argv) {
    int i = 0;
    {
        int i = 10;
        printf("%d\n", i);
    }
    printf("%d\n", i);
}

Answer 3

I don't think you need the if(true) portion.

Just the { } are required to scope the variables.

Answer 4

My answer is as follows:

This makes seasoned programmers cringe at the very thought of it.

Answer 5

Note that in C99 it is allowed to declare local variables in the middle of blocks.

C99 is the version of the C standard from the year 1999; most modern C compilers support it.