C | Variable Declaration and Scope | Question 3

#include <stdio.h>
extern int var;
int main()
{
    var = 10;
    printf("%d ", var);
    return 0;
}

(A) Compiler Error: var is not defined
(B) 20
(C) 0


Answer: (A)

Explanation: var is only declared and not defined (no memory allocated for it)

Refer: Understanding “extern” keyword in C

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