C Programming - C Preprocessor - Discussion

Discussion Forum : C Preprocessor - Find Output of Program (Q.No. 4)
4.
What will be the output of the program?
#include<stdio.h>
#define JOIN(s1, s2) printf("%s=%s %s=%s \n", #s1, s1, #s2, s2);
int main()
{
    char *str1="India";
    char *str2="BIX";
    JOIN(str1, str2);
    return 0;
}
str1=IndiaBIX str2=BIX
str1=India str2=BIX
str1=India str2=IndiaBIX
Error: in macro substitution
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
35 comments Page 2 of 4.

Neeraja said:   1 decade ago
Please give clarity what #s1 #s2 means?

Shashwat said:   1 decade ago
We have to add semicolon either at the macro declaration or while calling macro.

Sunil Kothari said:   1 decade ago
#include<stdio.h>
#define cube(x) (x*x*x)

void main()

{
int a,b =3;
a= cube(++b);
printf("%d \n %d", a, b);
}

Output:
-------
150
6

Please explain above program?

Avinash said:   1 decade ago
# symbol is used to print the actual arguments that are passed to function.

Gaurav Kumar Garg said:   1 decade ago
@Sachin Kumar.

Its your choice you can also remove semicolon. without semi colon it will also work.

With semi colon in macro
You can also call JOIN(str1, str2) <--- no semicolon.

Nandini said:   1 decade ago
#is name of the variable. So, if #str1 gives str1 content.

Sachin Kumar said:   1 decade ago
Can anyone explain me that why semi-colon(;) is used because we can't use semi-colon in macros ?

Sparsh610 said:   1 decade ago
It only works in macros ?

Or we can print them in main function too ?

Durga dutt said:   1 decade ago
isn't an error if we use ";" at the end of macro expansion?

Vimala said:   1 decade ago
# defines that name of the variable.


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