Читать книгу OCP Oracle Certified Professional Java SE 17 Developer Study Guide - Jeanne Boyarsky - Страница 97

The last thing you need to know about numeric literals is that you can have underscores in numbers to make them easier to read:

int million1 = 1000000; int million2 = 1_000_000;

We'd rather be reading the latter one because the zeros don't run together. You can add underscores anywhere except at the beginning of a literal, the end of a literal, right before a decimal point, or right after a decimal point. You can even place multiple underscore characters next to each other, although we don't recommend it.

Let's look at a few examples:

double notAtStart = _1000.00; // DOES NOT COMPILE double notAtEnd = 1000.00_; // DOES NOT COMPILE double notByDecimal = 1000_.00; // DOES NOT COMPILE double annoyingButLegal = 1_00_0.0_0; // Ugly, but compiles double reallyUgly = 1__________2; // Also compiles