In Java 8, underscore (``++_++``) cannot be used as a parameter to a lambda, and by Java 9, it's a keyword. To ensure future portability (not to mention current readability), it should not be used now as an identifier. == Noncompliant Code Example ---- private String _; // Noncompliant ---- == Compliant Solution ---- private String foo; ---- ifdef::rspecator-view[] == Comments And Links (visible only on this page) include::../comments-and-links.adoc[] endif::rspecator-view[]