# How to use variable in a regular expression

**URL:** <https://www.ruby-forum.com/t/how-to-use-variable-in-a-regular-expression/98934>\
**Category:** Ruby\
**Created:** [July 19, 2006, 3:38am UTC](https://www.ruby-forum.com/t/how-to-use-variable-in-a-regular-expression/98934 "2006-07-19T03:38:23Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![unknown](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/u/4bbf92/32.png) [@unknown](https://www.ruby-forum.com/u/unknown)\
**Post date:** [July 19, 2006, 3:38am UTC](https://www.ruby-forum.com/t/how-to-use-variable-in-a-regular-expression/98934/1 "2006-07-19T03:38:23Z")

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HI  
For ex i want to check for pattern variable in watir - Ruby and search  
like following

pattern= ‘oo’  
ie.button(:value, /pattern/i).click

How do i do it.

Seede

---

<div class="post-metadata">

**Author:** ![unknown](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/u/4bbf92/32.png) [@unknown](https://www.ruby-forum.com/u/unknown)\
**Post date:** [July 19, 2006, 4:42am UTC](https://www.ruby-forum.com/t/how-to-use-variable-in-a-regular-expression/98934/2 "2006-07-19T04:42:57Z")

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unknown wrote:

> HI  
> For ex i want to check for pattern variable in watir - Ruby and search  
> like following
> 
> pattern= ‘oo’  
> ie.button(:value, /pattern/i).click
> 
> How do i do it.
> 
> Seede

use #{variable\_name} inside the regexp

vis:  
irb(main):018:0\> fred = “bob”  
=\> “bob”  
irb(main):019:0\> " my name is fred flintsone" =~ /#{fred}/  
=\> nil  
irb(main):020:0\> “my name is bob bowden” =~ /#{fred}/  
=\> 11

best,  
jp