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Thank you for all the information. &nbsp;I added /. so I can match those strings with a '.'.
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Thank you for all the information.  I added /. so I can match those strings with a '.'.

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I have this string and I am not understanding the whole thing. &nbsp;Can someone please help me out?<br />
<br />
if(Regex.IsMatch(fileNumbe<wbr />rString,&quot;^<wbr />[0-9]{5}[A<wbr />-Za-z0-9]*<wbr />$&quot;)==false<wbr />)<br />
<br />
The portion I am having a problem with is &quot;^[0-9]{5}[A-Za-z0-9]*$&quot;<br />
<br />
&nbsp;[0-9] &nbsp; &nbsp; &nbsp; &nbsp;I am assuming this is looking for a number<br />
{5} &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; I don't know what this is for<br />
[A-Za-z0-9] &nbsp; &nbsp; &nbsp; I am assuming this is looking for upper or lower case letters and adding the 0-9 means it can be a combination of letters and numbers.<br />
*$ &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; I don't know what this is for except to end the regex.<br />
<br />
<br />
I want to add a condition. &nbsp;I need to look for a '.' &nbsp;I believe I need to escape this '/.' but I don't know where to add it.<br />
<br />
Thanks in advance.
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I have this string and I am not understanding the whole thing.  Can someone please help me out?

if(Regex.IsMatch(fileNumberString,"^[0-9]{5}[A-Za-z0-9]*$")==false)

The portion I am having a problem with is "^[0-9]{5}[A-Za-z0-9]*$"

 [0-9]        I am assuming this is looking for a number
{5}             I don't know what this is for
[A-Za-z0-9]       I am assuming this is looking for upper or lower case letters and adding the 0-9 means it can be a combination of letters and numbers.
*$               I don't know what this is for except to end the regex.


I want to add a condition.  I need to look for a '.'  I believe I need to escape this '/.' but I don't know where to add it.

Thanks in advance.

Understanding a RegEx for C#

C# is an object-oriented programming language created in conjunction with Microsoft’s .NET framework. Compilation is usually done into the Microsoft Intermediate Language (MSIL), which is then JIT-compiled to native code (and cached) during execution in the Common Language Runtime (CLR).

A regular expression ("regex") is a sequence of characters that define a search pattern, mainly for use in pattern matching with strings, or string matching, i.e. "find and replace"-like operations. Regular expression processors are found in several search engines, search and replace dialogs of several word processors and text editors, and in the command lines of text processing utilities, such as sed and AWK. Many programming languages provide regular expression capabilities, some built-in, for example Perl, JavaScript, Ruby, AWK, and Tcl, and others via a standard library, for example .NET languages, Java, Python and C++ (since C++11). Most other languages offer regular expressions via a library.