Thread: Declaring variables in int main()?

Is it good practice to declares variables (and/or functions) within the int main() function? Don't they have to be initialized before they're called, and the initializing takes places outside (and before) the int main() function?
I'm asking because I've seen a few tutorials on this site, that have the code declaring the variables within the int main() function.

You should keep your initialising in a function (any function, not just main), or a class, or namespace, etc. Having it outside these means that it is global. It will work having it both inside and out, but it is best to keep it in something so there aren't unexpected name clashes.

I'd be itnerested in where you have been learning the language, you've obviously learned some strange things --

It is perfectly conventional to define/declare variables that are local to the a function

Code:

int main() 
{
    int a; int b; // variables declared in main

    a = b = 0; // initialize them!
}

even if it is main. You can not define functions within the main function (however you can declare them)

Code:

int main()
{
    // error C2601: 'sub' : local function definitions are illegal
    int sub()
    {
        return bar; 
    }

    // declares that a function 'foo' exists and shall be resolved by the linker    
    int foo();

}

You can also define and declare variables outside of main (in functions other than main or global variables)

Code:

#include <stdio.h>
int a = 0, b = 0; // global variables

void bar(); // regular function declaration

int main()
{
	void foo(); // this is weird to declare function inside of main
	foo();
	bar();
}

void foo()
{
	a = b = 1;
}

void bar()
{
	printf("%d %d", a, b);
}

Thanks. Any particular reason why you used C in the last example, instead of C++ (the language I'm writing my program in)?
Anyways, I just have one more short question...
What about arrays?
Would you declare (and define) that inside the function its relevant for, too, or does it matter?