<div>
To match the dash 0 or 1 times:<br />
<br />
(?&lt;=GL_)\d+-{0,1}\d+|(?&lt;=G<wbr />R_).*
</div>


To match the dash 0 or 1 times:

(?<=GL_)\d+-{0,1}\d+|(?<=GR_).*

<div>
You want to match the number if the dash is there or if it is not. &nbsp;If it is there, it will not be there more than once. &nbsp;So we need to match the dash 0 or 1 time. The matching of digits has not changed. &nbsp;Try it for yourself.
</div>


You want to match the number if the dash is there or if it is not.  If it is there, it will not be there more than once.  So we need to match the dash 0 or 1 time. The matching of digits has not changed.  Try it for yourself.

<div>
Its not working if I try with this :<br />
<br />
<br />
GL_103923-323-433334<br />
<br />
<br />
the match will be only on : &nbsp; 103923-323<br />
<br />
result would need to match: &nbsp; &nbsp;103923-323-433334
</div>


Its not working if I try with this :


GL_103923-323-433334


the match will be only on :   103923-323

result would need to match:    103923-323-433334

<div>
For the multiple digit-hyphen combos:<br />
<br />

<pre><code id="code-20-37806157-1">(?&lt;=GL_)\d+(?:-\d+)*|(?&lt;=GR_).*</code></pre>
</div>


For the multiple digit-hyphen combos:



(?<=GL_)\d+(?:-\d+)*|(?<=GR_).*

<div>
<div class="content wysiwyg-content">
Hello Again EE,<br />
<br />
Mostly for Kaufmed and TerryOpus,<br />
<br />
<br />
with that regex:<br />
<br />
(?&lt;=GL_)\d+-\d+|(?&lt;=GR_).*<wbr /><br />
<br />
<br />
what if I would like the dash to be optional after GL_ &nbsp;? (dash is between some numbers)<br />
also It might happen there would be more dashes like this:<br />
<br />
<br />
GL_100-390-3992-1 (several dashes)<br />
or this:<br />
GL_9383-1384 &nbsp;(1 dash)<br />
or this:<br />
GL_1900000 &nbsp; &nbsp;(no dash)
</div>
</div>


Hello Again EE,

Mostly for Kaufmed and TerryOpus,


with that regex:

(?<=GL_)\d+-\d+|(?<=GR_).*


what if I would like the dash to be optional after GL_  ? (dash is between some numbers)
also It might happen there would be more dashes like this:


GL_100-390-3992-1 (several dashes)
or this:
GL_9383-1384  (1 dash)
or this:
GL_1900000    (no dash)

Help with Regex 2

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.

Regular Expressions

Visual Basic .NET (VB.NET) is an object-oriented programming language implemented on the .NET framework, but also supported on other platforms such as Mono and Silverlight. Microsoft launched VB.NET as the successor to the Visual Basic language. Though it is similar in syntax to  Visual Basic pre-2002, it is not the same technology,

Visual Basic.NET

The .NET Framework is not specific to any one programming language; rather, it includes a library of functions that allows developers to rapidly build applications. Several supported languages include C#, VB.NET, C++ or ASP.NET.