CODEWITHSUNDEEP
cprintf
user3202188
user3202188

Reputation: 151

Behavior of printf()

#include <stdio.h>

int main()
{

    printf(5 + "Good Morning\n");

    return 0;
}

The code prints Morning. Should the code print Morning or should it show undefined behavior?

Upvotes: 5

Views: 308

Answers (2)

rullof
rullof

Reputation: 7442

The code is correct since printf is defined as:

int printf ( const char * format, ... );

And according to pointers arithmitic 5 + "Good Morning\n" is a pointer to the first element of "Morning\n". So the statment:

printf(5 + "Good Morning\n");

has the same result as:

printf("Morning\n");

Explanation:

                     |G|o|o|d| |M|o|r|n|i|n|g|\n|
                      ^         ^
                      |         |
"Good Morning\n" >----          |
       +                        |
       5 >----------------------

Upvotes: 6

abligh
abligh

Reputation: 25189

It should show 'Morning'.

You are using pointer arithmetic - though you appear not to know it! "Good Morning\n" is a char * pointer to a constant string. You are then adding 5 to this pointer, which advances it by 5 characters. Hence the pointer now points to the 'M' of 'Morning'.

Upvotes: 11

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