Variable name convention

rubyonrails-talk
1

Hello All,

still a newbie in rails and would like to know when I shoud place a '@' before a variable name and when not ?

Regards,

Joel

2

Hi Joel,

The @ symbol is (through my experience) generally used for sharing variables between controllers and views. So in your controller, you'd have something like:

@var = Users.find(...)

And in your view:

<%= "Hi, " + @var.first_name %>

But, again, that's just how I use it :slight_smile:

3

It has nothing to do with convention.

@foo is an instance variable

foo is a local variable

http://www.ruby-doc.org/docs/ProgrammingRuby/

In particular: Programming Ruby: The Pragmatic Programmer's Guide

4

joel wrote:

Hello All,

still a newbie in rails and would like to know when I shoud place a '@' before a variable name and when not ?

Regards,

Joel

See here: http://www.ruby-doc.org/docs/ProgrammingRuby/html/tut_classes.html

5

Ok Great !

Thanks Guys for these resources !

Joel

6

foo could also be a method!

Be wary of the fact that local variables take precedence over methods, as shown in this example:

>> foo = "woot" => "woot" >> def foo >> "bar" >> end => nil >> foo => "woot"

7

To avoid that you can just write foo() i.e. with the parentheses, if you want to call the function.

8

OK ! Nice information guys !

Thanks !

Joel

9

foo could also be a method!

Be wary of the fact that local variables take precedence over methods, as shown in this example:

A common mistake related to this is

class Foo    attr_accessor :bar    def some_method      bar = true    end end

This does not call the accessor, and does not set @bar (only the local
variable bar).

Fred