C file scope of variable

File Scope of Variable :

  1. File Scope is also called Global Scope
  2. It can be used outside the function or a block
  3. It is visible in entire program
  4. Variables defined within Global scope is called as Global variables

Definition :

Variable is said to have global scope / file scope if it is defined outside the  function and whose visibility is entire program

 Live Example :

void message();
int num1 = 1; // Global 

void main()
int num1 = 6 ; 
printf("%d",num1); // Local variable is accessed

void message()
printf("%d",num1); // Global variable is accessed

Output :

6 1

Explanation :

  1. Program have two functions main and message
  2. As num1 declared in main is local to main , so it can be accessed from main
  3. But num1 is not defined in the function message , then global variable is accessed