Double does not output 0, how to fix?

Question

Programming

This is what 0 looks like ( 1.58871e-10)

Answer 1

What makes you think it's zero? This is exactly 1.58871 * 10 ^-10
Arithmetic operations with real numbers on a computer are performed with a certain error, and this is exactly how it manifests itself.

Answer 2

No way. For real numbers, the value 0 does not exist.
To work with real numbers, it is necessary to introduce the concept of error. then
e = 0.0000001;
........................
if Abs(A - B) < e then ............

Answer 3

Here is the code itself, how can I fix it then?

Answer 4

это норма. Тут объяснили, почему так. Только никто не удосужился посоветовать самое простое решение:
Используйте форматированный вывод, например так:
для cout тоже есть форматированный вывод, если принтф не устраивает