Q1:

Will the program compile successfully?

#include<stdio.h>

int main()
{
    #ifdef NOTE
        int a;
        a=10;
    #else
        int a;
        a=20;
    #endif
    printf("%d\n", a);
    return 0;
}

ANS:A - Yes

Yes, this program will compile and run successfully and prints 20. The macro #ifdef NOTE evaluates the given expression to 1. If satisfied it executes the #ifdef block statements. Here #ifdef condition fails because the Macro NOTE is nowhere declared. Hence the #else block gets executed, the variable a is declared and assigned a value of 20. printf("%d\n", a); It prints the value of variable a 20.