# Params hash in rails

**URL:** <https://www.ruby-forum.com/t/params-hash-in-rails/196806>\
**Category:** Rails\
**Created:** [September 12, 2008, 8:48am UTC](https://www.ruby-forum.com/t/params-hash-in-rails/196806 "2008-09-12T08:48:03Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![sunfish](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/96bed5/32.png) [@sunfish](https://www.ruby-forum.com/u/sunfish)\
**Post date:** [September 12, 2008, 8:48am UTC](https://www.ruby-forum.com/t/params-hash-in-rails/196806/1 "2008-09-12T08:48:03Z")

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Hi,  
I want to know that how ‘params’ get created in rails?  
when http: request comes we have get all parameter using hash params  
e.g:- params[:id]  
But in ActionController how params get created and how it is  
initialised there?  
Also what is scope for params?

```
         Thanks.
```

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<div class="post-metadata">

**Author:** ![sunfish](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/96bed5/32.png) [@sunfish](https://www.ruby-forum.com/u/sunfish)\
**Post date:** [September 12, 2008, 9:55am UTC](https://www.ruby-forum.com/t/params-hash-in-rails/196806/2 "2008-09-12T09:55:58Z")

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On Sep 12, 7:48 am, Sunny B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> Hi,  
> I want to know that how ‘params’ get created in rails?  
> when http: request comes we have get all parameter using hash params  
> e.g:- params[:id]  
> But in ActionController how params get created and how it is  
> initialised there?  
> Also what is scope for params?

It’s created from the request body and query string (details of the  
parsing are in request.rb).  
It’s an instance method on controllers (which views can call via the  
usual magic).

Fred

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<div class="post-metadata">

**Author:** ![sunfish](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/96bed5/32.png) [@sunfish](https://www.ruby-forum.com/u/sunfish)\
**Post date:** [September 12, 2008, 10:09am UTC](https://www.ruby-forum.com/t/params-hash-in-rails/196806/3 "2008-09-12T10:09:58Z")

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Could you explain me this in detail ?

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<div class="post-metadata">

**Author:** ![sunfish](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/96bed5/32.png) [@sunfish](https://www.ruby-forum.com/u/sunfish)\
**Post date:** [September 12, 2008, 10:41am UTC](https://www.ruby-forum.com/t/params-hash-in-rails/196806/4 "2008-09-12T10:41:04Z")

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On 12 Sep 2008, at 09:09, Sunny B. wrote:

> Could you explain me this in detail ?

Unless there’s something specific you’re after you’re better off  
reading the code yourself. It’s just a bunch of regexpy type things  
pulling apart the query string/form data

Fred