rspec/rules/S4201/java/rule.adoc

== Why is this an issue?

There's no need to null test in conjunction with an ``++instanceof++`` test. ``++null++`` is not an ``++instanceof++`` anything, so a null check is redundant.


=== Noncompliant code example

[source,java]
----
if (x != null && x instanceof MyClass) { ... }  // Noncompliant

if (x == null || ! x instanceof MyClass) { ... } // Noncompliant
----


=== Compliant solution

[source,java]
----
if (x instanceof MyClass) { ... }

if (! x instanceof MyClass) { ... }
----

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

include::../message.adoc[]

include::../highlighting.adoc[]

endif::env-github,rspecator-view[]