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    <p>Suppose you don't initialize your <code>String</code> variable. And there goes some processing. In the end you expect get a definitive value, which you return via a <code>Return</code> statement. If, for some reason, you forgot to account for a possible execution path, VS will warn you about possible null-reference exception. Then you may think to yourself: "oh yeah, how did I forget that?"</p> <p>For example, you have a <code>Function</code> that converts a <code>Integer</code> into a word (limited practical use, so consider it just for demo purposes):</p> <pre><code>Function ConvertIntToWord(a As Integer) As String Dim retString As String If a = 0 retString = "Zero " ElseIf a = 1 retString = "One " End If Return retString End Function </code></pre> <p>In the above lines, you were unlucky to forget about the <code>Else</code> path. Then suppose you want to run further processing on a resulting string:</p> <pre><code>ConvertIntToWord(5).TrimEnd </code></pre> <p>With 5 passed as an argument, you will get an exception at this point. If you instead listened to VS, you would have noticed a warning - underlined <code>retString</code> in <code>Return retString</code> line. So you could fix this problem without running your code.</p> <p>Now suppose you initialize <code>Dim retString As String = ""</code>. You will no longer see the warning, and have to debug your program to solve this issue. Depending on the complexity of your program, it may take much more effort.</p> <p>Bottom line - it is always better to spot problems in compile time, rather than run-time.</p> <p><strong>EDIT:</strong> Forgetting to initialize a variable can be intentional, for example why using <a href="http://msdn.microsoft.com/en-us/library/bb347013.aspx" rel="nofollow">TryGetValue</a>. For this method, value <code>is passed uninitialized</code>, according to documentation. However, VS does not know about this, so it will continue to show a warning, until you explicitly assign it to <code>Nothing</code>:</p> <pre><code>Dim retString As String = Nothing </code></pre> <p>So this is a way to tell VS that yes, you know it is uninitialized, but for this particular scenario, it is intentional.</p>
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    1. POWhat could be some reasons to allow some run-time exceptions to fall through?
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    1. POWhat could be some reasons to allow some run-time exceptions to fall through?
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    1. COWorld you ever see the error and say " yes, this time it was intentional"?
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    2. CO@Onwuka: yes, it is possible - see my edit.
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    3. COThank you. Upvoted.
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