# Sub(/variable/,'')

**URL:** <https://rubytalk.org/t/sub-variable/20000>\
**Category:** ruby-talk\
**Created:** [7 August 2005 20:16 UTC](https://rubytalk.org/t/sub-variable/20000 "2005-08-07T20:16:08Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![Marcin\_Jurczuk](https://avatars.discourse-cdn.com/v4/letter/m/bbce88/32.png) [@Marcin\_Jurczuk](https://rubytalk.org/u/Marcin_Jurczuk)\
**Post date:** [7 August 2005 20:16 UTC](https://rubytalk.org/t/sub-variable/20000/1 "2005-08-07T20:16:08Z")

</div>

Helo here is my problem:

C:\Documents and Settings\spock\>irb  
irb(main):001:0\> a="DEL"  
=\> "DEL"  
irb(main):002:0\> b="DELETE"  
=\> "DELETE"  
irb(main):003:0\> b.sub(/a/,'')  
=\> "DELETE"  
irb(main):004:0\> b.sub(/DEL/,'')  
=\> "ETE"  
irb(main):005:0\> quit

How use variable "a" as sub argument ?

> **···**
>
> --  
> Marcin Jurczuk, NIC-HDL: MJ1679-RIPE

---

<div class="post-metadata">

**Author:** ![James\_Edward\_Gray\_II](https://avatars.discourse-cdn.com/v4/letter/j/ea5d25/32.png) [@James\_Edward\_Gray\_II](https://rubytalk.org/u/James_Edward_Gray_II)\
**Post date:** [7 August 2005 20:24 UTC](https://rubytalk.org/t/sub-variable/20000/2 "2005-08-07T20:24:23Z")

</div>

Just as you include a variable in a string:

b.sub(/#{a}/, "")

Hope that helps.

James Edward Gray II

> **···**
>
> On Aug 7, 2005, at 3:16 PM, Marcin Jurczuk wrote:
> 
> > Helo here is my problem:
> > 
> > C:\Documents and Settings\spock\>irb  
> > irb(main):001:0\> a="DEL"  
> > =\> "DEL"  
> > irb(main):002:0\> b="DELETE"  
> > =\> "DELETE"  
> > irb(main):003:0\> b.sub(/a/,'')  
> > =\> "DELETE"  
> > irb(main):004:0\> b.sub(/DEL/,'')  
> > =\> "ETE"  
> > irb(main):005:0\> quit
> > 
> > How use variable "a" as sub argument ?

---

<div class="post-metadata">

**Author:** ![Zach\_Dennis1](https://avatars.discourse-cdn.com/v4/letter/z/ea5d25/32.png) [@Zach\_Dennis1](https://rubytalk.org/u/Zach_Dennis1)\
**Post date:** [7 August 2005 20:25 UTC](https://rubytalk.org/t/sub-variable/20000/3 "2005-08-07T20:25:10Z")

</div>

Marcin Jurczuk wrote:

> Helo here is my problem:
> 
> C:\Documents and Settings\spock\>irb  
> irb(main):001:0\> a="DEL"  
> =\> "DEL"  
> irb(main):002:0\> b="DELETE"  
> =\> "DELETE"  
> irb(main):003:0\> b.sub(/a/,'')  
> =\> "DELETE"  
> irb(main):004:0\> b.sub(/DEL/,'')  
> =\> "ETE"  
> irb(main):005:0\> quit
> 
> How use variable "a" as sub argument ?

a="DEL"  
b="DELETE"  
b.sub( /#{a}/, '' )

Zach

---

<div class="post-metadata">

**Author:** ![Joel\_VanderWerf1](https://avatars.discourse-cdn.com/v4/letter/j/94ad74/32.png) [@Joel\_VanderWerf1](https://rubytalk.org/u/Joel_VanderWerf1)\
**Post date:** [7 August 2005 20:25 UTC](https://rubytalk.org/t/sub-variable/20000/4 "2005-08-07T20:25:42Z")

</div>

Marcin Jurczuk wrote:

> Helo here is my problem:
> 
> C:\Documents and Settings\spock\>irb  
> irb(main):001:0\> a="DEL"  
> =\> "DEL"  
> irb(main):002:0\> b="DELETE"  
> =\> "DELETE"  
> irb(main):003:0\> b.sub(/a/,'')  
> =\> "DELETE"  
> irb(main):004:0\> b.sub(/DEL/,'')  
> =\> "ETE"  
> irb(main):005:0\> quit
> 
> How use variable "a" as sub argument ?

irb(main):001:0\> a = "DEL"  
=\> "DEL"  
irb(main):002:0\> b = "DELETE"  
=\> "DELETE"  
irb(main):003:0\> b.sub(/#{a}/,'')  
=\> "ETE"  
irb(main):004:0\> b.sub(a,'')  
=\> "ETE"

> **···**
>
> --  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407

---

<div class="post-metadata">

**Author:** ![Spock](https://avatars.discourse-cdn.com/v4/letter/s/7c8e57/32.png) [@Spock](https://rubytalk.org/u/Spock)\
**Post date:** [7 August 2005 21:11 UTC](https://rubytalk.org/t/sub-variable/20000/5 "2005-08-07T21:11:08Z")

</div>

James Edward Gray II napisal(a):

> **···**
>
> > On Aug 7, 2005, at 3:16 PM, Marcin Jurczuk wrote:
> 
> > \>  
> > \> How use variable "a" as sub argument ?
> > 
> > Just as you include a variable in a string:
> > 
> > b.sub(/#{a}/, "")
> > 
> > Hope that helps.
> > 
> > James Edward Gray II
> 
> It helps a lot 🙂  
> Thx.

---

<div class="post-metadata">

**Author:** ![Shalev\_NessAiver](https://avatars.discourse-cdn.com/v4/letter/s/58956e/32.png) [@Shalev\_NessAiver](https://rubytalk.org/u/Shalev_NessAiver)\
**Post date:** [7 August 2005 21:16 UTC](https://rubytalk.org/t/sub-variable/20000/6 "2005-08-07T21:16:34Z")

</div>

You can also do:

irb(main):002:0\> a = /DEL/  
=\> /DEL/  
irb(main):003:0\> b = "DELETE"  
=\> "DELETE"  
irb(main):004:0\> b.sub(a,'')  
=\> "ETE"

> **···**
>
> On Aug 7, 2005, at 5:11 PM, Spock wrote:
> 
> > James Edward Gray II napisal(a):
> > 
> > > On Aug 7, 2005, at 3:16 PM, Marcin Jurczuk wrote:
> > > 
> > > > How use variable "a" as sub argument ?
> > > 
> > > Just as you include a variable in a string:
> > > 
> > > b.sub(/#{a}/, "")
> > > 
> > > Hope that helps.
> > > 
> > > James Edward Gray II