Is “int a;” a declaration or definition in C and in C++?

Question

Is int a; a declaration or definition in C? Is there any difference in C++?

I was always thinking it\'s just a declaration, until today...

Is i

Answer 1

Consider:

int a;

It's a definition as well as a declaration.

Consider the following example...

int i;
printf("%d", i);

Some junk value will be printed. Which obviously means it's got a memory location.

If you want to just declare a variable and not define it then go for "extern" keyword.

Thus extern int b; is just a declaration and not a definition.

Example:

extern int var;
int main(void)
{
    var = 10;
    return 0;
}

Thus the above program will throw an error as "var" was not defined anywhere.