== Why is this an issue?

``++NullReferenceException++`` should be avoided, not caught. Any situation in which ``++NullReferenceException++`` is explicitly caught can easily be converted to a ``++null++`` test, and any behavior being carried out in the catch block can easily be moved to the "is null" branch of the conditional.

=== Noncompliant code example

[source,csharp]
----
public int GetLengthPlusTwo(string str) 
{
    int length = 2;
    try 
    {
       length += str.Length;
    }
    catch (NullReferenceException e) 
    {
        log.info("argument was null");
    }
    return length;
}
----

=== Compliant solution

[source,csharp]
----
public int GetLengthPlusTwo(string str) 
{
    int length = 2;

    if (str != null) 
    {
        length += str.Length;
    }
    else 
    {
        log.info("argument was null");
    }
    return length;
}
----

== Resources

* CWE - https://cwe.mitre.org/data/definitions/395[CWE-395 - Use of NullPointerException Catch to Detect NULL Pointer Dereference]

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

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

=== Message

Do not catch NullReferenceException; test for null instead.


=== Highlighting

throw new NullReferenceException()


'''
== Comments And Links
(visible only on this page)

include::../comments-and-links.adoc[]

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