While ``++null++`` is technically a valid ``++Boolean++`` value, that fact, and the distinction between ``++Boolean++`` and ``++boolean++`` is easy to forget. So returning ``++null++`` from a ``++Boolean++`` method is likely to cause problems with callers' code.


== Noncompliant Code Example

----
public Boolean isUsable() {
  // ...
  return null;  // Noncompliant
}
----


== See

* http://cwe.mitre.org/data/definitions/476.html[MITRE CWE-476] - NULL Pointer Dereference
* https://wiki.sei.cmu.edu/confluence/x/aDdGBQ[CERT, EXP01-J.] - Do not use a null in a case where an object is required

