1. 

What is the output of the program? 

#include<stdio.h>
int main()
{
    extern int a;
    printf("%d\n", a);
    return 0;
}
int a=20;


A. 20
B. 0
C. Garbage Value
D. Error

Answer: Option

Explanation:

extern int a; indicates that the variable a is defined elsewhere, usually in a separate source code module.

printf("%d\n", a); it prints the value of local variable int a = 20. Because, whenever there is a conflict between local variable and global variable, local variable gets the highest priority. So it prints 20.