Regular expression pattern.

Question

1.00/5 (1 vote)

See more:

Hi Everyone,

Please explain the below regular expression pattern. What characters it allows.
And what is '*' here ?

<xsd:complexType name="NameType">
 <xsd:sequence>
  <xsd:element name="FirstName">
	<xsd:simpleType>
	  <xsd:restriction base="xsd:string">
		 <xsd:maxLength value="16"/>
		  <xsd:pattern value="([A-Za-z0-9'\-] ?)*[A-Za-z0-9'\-]"/>
	    </xsd:restriction>
	  </xsd:simpleType>
  </xsd:element>
 </xsd:sequence>
</xsd:complexType>

Please guide me how to understand [A-Za-z0-9'\-] ?)*[A-Za-z0-9'\-] pattern.

What I have tried:

As per my assumption it allows A-Z, a-z ,0-9 and spacial characters like Back slash,
Single Quote, and Hyphen.

Posted 14-Jun-17 20:44pm

suman palla

Updated 14-Jun-17 21:04pm

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Kornfeld Eliyahu Peter · Answer 1 · 2017-06-14T20:59:00

Solution 1

Regexper[^]

Posted 14-Jun-17 20:59pm

Kornfeld Eliyahu Peter

Patrice T · Answer 2 · 2017-06-14T21:04:00

Quote:
As per my assumption it allows A-Z, a-z ,0-9 and spacial characters like Back slash,
Single Quote, and Hyphen.

Your RegEx is a little more complex than that, looks like your problem is that you use RegEx without really learning it.
Use last link and paste the RegEx and you will see a nice graph of your RegEx, hope it helps you to understand it.

Just a few interesting links to help building and debugging RegEx.
Here is a link to RegEx documentation:
perlre - perldoc.perl.org[^]
Here is links to tools to help build RegEx and debug them:
.NET Regex Tester - Regex Storm[^]
Expresso Regular Expression Tool[^]
This one show you the RegEx as a nice graph which is really helpful to understand what is doing a RegEx:
Debuggex: Online visual regex tester. JavaScript, Python, and PCRE.[^]