cfloating-pointintegerprintf

Why isn't printf printing a float passed by a variable?

Why is the following:

int main(void)
{
    double b = 11/2;
    double a = 2;
    printf("%lf\n", a + b);
    printf("%lf\n", b);
}

printing, respectively, 7.000000 and 5.000000

I tried printing just the value of 5.5, without having it in a variable and then passing it to printf and it worked, but why does this code don't?

Solution

  • The constants 11 and 2 have type int, so dividing them performs integer division which truncates any fractional part.

    Use floating point constants instead so floating point division happens.

    double b = 11.0/2.0;