Download Aptitude Crack
img not found img not found

C Preprocessor - Programming

Q1:

What will be the output of the program? 
#include<stdio.h>
#define str(x) #x
#define Xstr(x) str(x)
#define oper multiply

int main()
{
    char *opername = Xstr(oper);
    printf('%s\n', opername);
    return 0;
}

A Error: in macro substitution

B Error: invalid reference 'x' in macro

C print 'multiply'

D No output

ANS:A - Error: in macro substitution

The macro #define str(x) #x replaces the symbol 'str(x)' with 'x'. The macro #define Xstr(x) str(x) replaces the symbol 'Xstr(x)' with 'str(x)'. The macro #define oper multiply replaces the symbol 'oper' with 'multiply'. Step 1: char *opername = Xstr(oper); The varible *opername is declared as an pointer to a character type. => Xstr(oper); becomes, => Xstr(multiply); => str(multiply) => char *opername = multiply Step 2: printf('%s\n', opername); It prints the value of variable opername. Hence the output of the program is 'multiply'