MissedReadonlyOpportunity.qhelp

<!DOCTYPE qhelp PUBLIC
  "-//Semmle//qhelp//EN"
  "qhelp.dtd">
<qhelp>
<overview>
<p>
A private field where all assignments occur as part of the declaration or in a constructor
in the same class can be <code>readonly</code>. Making a field <code>readonly</code>
prevents unintended assignments after object initialization.
</p>

</overview>
<recommendation>

<p>
Add a <code>readonly</code> modifier to the field, unless changes to the field are
allowed after object initialization.
</p>

</recommendation>
<example>
<p>
In the following example, the field <code>Field</code> is only assigned to in the
constructor, but it can still be modified after object initialization.
</p>
<sample src="MissedReadonlyOpportunityBad.cs" />

<p>
In the revised example, the field is made <code>readonly</code>.
</p>
<sample src="MissedReadonlyOpportunityGood.cs" />

</example>
<references>

<li>Microsoft: <a href="https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/readonly">readonly</a>.</li>

</references>
</qhelp>