C: What is the return value of a printf function?

Question

Say we have program like this

void main()
{
int a=10, b=20;
printf("%d %d");
}

above we are not providing a and b but program compiles and print some junk values.

Any explanation?

Answer 1

Return the number of characters printed (excluding the null byte used to end output to strings).

For example:

int main()
{
    printf("Num of char printed : %d\n", printf("Hello!"));
    return 0;
}

Output : Hello!Num of char printed : 6

Comments

It will print number of charecter printed by printf function
printf("Hello");
will return 5