AOL: The Dog Breed Famous for Its “Double Dewclaws” Was Built for the Mountains At first glance, the extra toes might look like a genetic quirk—or even a mistake. But for one powerful working breed, those unusual double dewclaws on the rear legs are no accident at all. They’re a ...

Understanding the Context

The Dog Breed Famous for Its “Double Dewclaws” Was Built for the Mountains En double se pueden almacenar números más grandes y también más decimales. Con los números que has probado no se ve diferencia porque cout << redondea la representación interna para mostrar pocos decimales, y lo que ves en ambos casos es lo mismo, pero internamente no son iguales. I've read about the difference between double precision and single precision. However, in most cases, float and double seem to be interchangeable, i.e.

Key Insights

using one or the other does not seem to affec... A double has a much higher precision due to it's difference in size. If the numbers you are using will commonly exceed the value of a float, then use a double. Several other people have mentioned performance isssues. That would be exactly last on my list of considerations.

Final Thoughts

Correctness should be your #1 consideration. 20 Format %lf is a perfectly correct printf format for double, exactly as you used it. There's nothing wrong with your code. Format %lf in printf was not supported in old (pre-C99) versions of C language, which created superficial "inconsistency" between format specifiers for double in printf and scanf. From what I have read, a value of data type double has an approximate precision of 15 decimal places. However, when I use a number whose decimal representation repeats, such as 1.0/7.0, I find tha...