CODEWITHSUNDEEP
c
manish
manish

Reputation: 974

C program confusing output

#include<stdio.h>


int main(){

        int main =22;
        printf("%d\n",main);
        return 0;
}

output:22 I am defining main as function and variable both even though compiler is not giving error. It should give error "error: redefinition of ‘main’ " . I am not able to understand why this code is working.

Upvotes: 4

Views: 121

Answers (4)

chouaib
chouaib

Reputation: 2817

#include <stdio.h>
#include <string.h>


void stuff();
main()
{
   int val = 10;
   printf("from main: %d\n", val);

   stuff();

   printf("from main: %d\n", val);

   stuff();
}

void stuff()
{
    int val = 5;
    printf("from stuff: %d\n", val);
}

It doesn't matter defining the int val many times as it matters in which scope it's defined, this will output 10 5 10 5 , no errror no bad behavior

Upvotes: 0

Sadique
Sadique

Reputation: 22841

It will not give you an error because main is not a keyword. but main is define 2 times - Scoping rules come into play.

Upvotes: 7

R Sahu
R Sahu

Reputation: 206717

The declaration of main inside the function creates a new identifier in the scope of the function. It does not override the main function which is defined in global scope.

Upvotes: 3

D&#233;j&#224; vu
D&#233;j&#224; vu

Reputation: 28850

The main function is in the global scope - while the variable main is defined within the function main scope. They're not at the same level, thus there is no conflict.

The int main=22; line tells the compiler to use (declare) the local variable main - there is no conflict / ambiguity.

Do 

int main(){

    return 0;
}

int main =22;

on the other hand and you'll get an error.

Upvotes: 3

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