CODEWITHSUNDEEP
ruby-on-railsrubyruby-on-rails-3methods
Crashalot
Crashalot

Reputation: 34513

Rails runner throwing "undefined local variable or method" error for simple script

When we invoke this command, rails runner test.rb -e production, we see this error:

test.rb:2:in `<top (required)>': undefined local variable or method `hello' for main:Object (NameError)
        from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.2.12/lib/rails/commands/runner.rb:51:in `eval'
        from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.2.12/lib/rails/commands/runner.rb:51:in `<top (required)>'
        from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.2.12/lib/rails/commands.rb:64:in `require'
        from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.2.12/lib/rails/commands.rb:64:in `<top (required)>'
        from script/rails:6:in `require'
        from script/rails:6:in `<main>'

Contents of test.rb:

hello

def hello
        puts "hi"

end

Why is this happening? We're on Rails 3.2.12.

Upvotes: 0

Views: 1973

Answers (2)

Arup Rakshit
Arup Rakshit

Reputation: 118271

hello # remove this one.

def hello
        puts "hi"

end

See the introspection :

defined? hello #=> nil # so here Ruby doesn't know who is "hello",and your call to hello thus throws the error.
def hello
        puts "hi"
end
defined? hello #=> "method"
hello #=> "hi"

Upvotes: 3

Danil Speransky
Danil Speransky

Reputation: 30463

Because you call a method before you declare it.

def hello
  puts "hi"
end

hello

Upvotes: 6

Related Questions