Question

I want to create a regular expression for subdomain like:

In the textbox user need to enter like

abc1.test.com

or

abc1s.test.com

Note: .test.com is always required at the end.

The variable part can contain any letter, alphabets etc

I dont know anything about regex so i ask this silly question. I googled it for more than 2 hours but dont find any good example.

Please note this is not a homework.

Any help is highly appreciated.

Answer 1

There are a number of useful resources on regex online, including:

• http://regexpal.com/ – test out your regex
• http://www.regular-expressions.info/reference.html – regex reference
• http://www.addedbytes.com/cheat-sheets/regular-expressions-cheat-sheet/ – useful cheat sheet

I am sure other members will have better resources but these have sufficed for me in the past.

The following regex should work for you:

^((.+)(.test.com){1})$

• the ‘.’ is any character except new line
• the ‘+’ is one or more times
• the ‘{1}’ is exactly once