ReadOnlyContainer.qhelp

<!DOCTYPE qhelp PUBLIC
  "-//Semmle//qhelp//EN"
  "qhelp.dtd">
<qhelp>

<overview>
<p>
Code that queries the contents of a collection (such as <code>ContainsKey</code>
or <code>Count</code>) is invoked on an object that is known to be empty. Such queries
do not return interesting results, and may indicate missing code or a logic error. 
</p>

</overview>
<recommendation>

<p>
Either remove the collection if it is unnecessary, or ensure that it contains the
correct data. 
</p>

</recommendation>
<example>

<p>
The following example code is supposed to return the name of the day, but does not work
because the collection <code>daysOfWeek</code> is never populated. When this code is run, an 
<code>ArgumentOutOfRangeException</code> exception is thrown.
</p> 

<sample src="ReadOnlyContainer.cs" />

<p>
This problem is fixed by populating the variable <code>daysOfWeek</code> with the correct data.
</p>

<sample src="ReadOnlyContainerFix.cs" />

</example>
</qhelp>