Comments on: A trap to avoid with ruby assignments http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/ Because programming should be fun Tue, 06 Jan 2009 04:16:03 +0000 http://wordpress.org/?v=2.1.2 By: Ben http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/#comment-27 Ben Mon, 26 Mar 2007 17:34:14 +0000 http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/#comment-27 The difference between the first and second cases is that instance variables in Ruby are essentially protected by default. There is no trap; assignment in Ruby is always performed using a method call. The difference between the first and second cases is that instance variables in Ruby are essentially protected by default. There is no trap; assignment in Ruby is always performed using a method call.

]]> By: Frank http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/#comment-28 Frank Mon, 26 Mar 2007 19:03:52 +0000 http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/#comment-28 Ben, I'm not sure to understand what you mean. if I write obj = MyClass.new, the equal sign isn't "bound" to any method name. This is what i was talking about. Ben,

I’m not sure to understand what you mean. if I write obj = MyClass.new, the equal sign isn’t “bound” to any method name. This is what i was talking about.

]]> By: Hugo http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/#comment-29 Hugo Mon, 26 Mar 2007 19:41:11 +0000 http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/#comment-29 Hi, I'm currently learning Ruby ( and, sure, Rails) and found your posts very interesting. I'm start to understanding the whole thing behind Ruby and all beauty of the language :) I understood why I use symbols all the times in Rails.. Tks Hi, I’m currently learning Ruby ( and, sure, Rails) and found your posts very interesting. I’m start to understanding the whole thing behind Ruby and all beauty of the language :)

I understood why I use symbols all the times in Rails..

Tks

]]> By: Ben http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/#comment-30 Ben Mon, 26 Mar 2007 19:54:05 +0000 http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/#comment-30 My mistake. For the longest time, I'd assumed that every action boiled down to a method call in Ruby. Guess not: <code>$ irb irb> hello = 'ted' => 'ted' irb> def hello; 'bob'; end => nil irb> hello => 'ted' irb> hello() => 'bob' </code> My mistake. For the longest time, I’d assumed that every action boiled down to a method call in Ruby. Guess not:

$ irb
irb> hello = 'ted'
=> 'ted'
irb> def hello; 'bob'; end
=> nil
irb> hello
=> 'ted'
irb> hello()
=> 'bob'

]]> By: Jörg W Mittag http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/#comment-32 Jörg W Mittag Mon, 26 Mar 2007 21:41:29 +0000 http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/#comment-32 There's one more way to create readers and writers, somewhere in between writing your own and calling attr_accessor or attr_reader: attr. attr takes a Symbol and an optional Boolean. The Symbol is the name of the accessor and the Boolean determines whether a writer is also created. The created accessor methods basically look exactly like the ones you demonstrated. attr_accessor and attr_reader take any number of Symbols and basically just call attr(:sym, true) or attr(:sym) for each one. However, I have no idea why and when one would actually want to use attr over attr_accessor. jwm There’s one more way to create readers and writers, somewhere in between writing your own and calling attr_accessor or attr_reader: attr. attr takes a Symbol and an optional Boolean. The Symbol is the name of the accessor and the Boolean determines whether a writer is also created. The created accessor methods basically look exactly like the ones you demonstrated.

attr_accessor and attr_reader take any number of Symbols and basically just call attr(:sym, true) or attr(:sym) for each one.

However, I have no idea why and when one would actually want to use attr over attr_accessor.

jwm

]]> By: Frank http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/#comment-33 Frank Mon, 26 Mar 2007 23:57:36 +0000 http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/#comment-33 Thanks everyone for your comments, i really appreciate. Hugo, your comment made my day. Knowing that some people appreciate my work means a lot to me. It's cool to see your interest in the language. Ruby is one wild beast but to me it's the most interesting and elegant language out there. Jörg, I didn't know about the attr keyword. Thanks for the input! Like you said however, I don't know why one would use it instead of the other more "verbose" helpers... Is it some deprecated feature? Thanks everyone for your comments, i really appreciate. Hugo, your comment made my day. Knowing that some people appreciate my work means a lot to me. It’s cool to see your interest in the language. Ruby is one wild beast but to me it’s the most interesting and elegant language out there.

Jörg, I didn’t know about the attr keyword. Thanks for the input! Like you said however, I don’t know why one would use it instead of the other more “verbose” helpers…

Is it some deprecated feature?

]]> By: sole http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/#comment-34 sole Tue, 27 Mar 2007 07:10:26 +0000 http://www.rubyfleebie.com/a-trap-to-avoid-with-ruby-assignments/#comment-34 Cool one! I already *supposedly* knew this but reading it again it helped clarifying and settling the concepts. Coming from a non-ruby background, I always forget how the attributes and accessors work in ruby :D Cool one! I already *supposedly* knew this but reading it again it helped clarifying and settling the concepts. Coming from a non-ruby background, I always forget how the attributes and accessors work in ruby :D

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