using extern with same parameter name inside function

Question

I have this c code that have a global variable

main_prog.c

PLD po;
int main(){}

i have this function in the definition

functiondef.c

void function(PLD po)
{
  extern po;
}

what my problem is that how do the compiler know that it is using the extern po or the parameter po??

Answer 1

You can definitely access the extern variable if you declare it in a different scope.

void function(PLD po)
{

    {
        extern PLD po;    //this is the po declared in main
    }
}