Stringify keys error when building a hash

Question

I am getting a stringify_keys error.

Currently I am calling the following method which works perfectly:

def attributes
  {
    city:         @content[1..20].strip,
    streetname:   @content[21..40].strip,
    house_number: @content[41..46].strip.to_i
  }
end

Now that I am refactoring my code, I need to build the hash from the ground up where the keys and values are populating the hash based on certain conditions (conditions are not written yet).

def attributes
  test = {}
  test["city"]          = @content[1..20].strip
  test["streetname"]    = @content[21..40].strip
  test["house_number"]  = @content[41..46].strip.to_i
end

Now I am getting the stringify_keys error. I checked the docs for clues on how to build a hash but there isn't anything that could help me.

Where is the problem? If you need more code, please ask.

Thanks but that doesn't work either. I am still getting the same error. — Robin van Dijk
– Robin van Dijk, Commented May 6, 2014 at 8:20
What @Monk_Code said is true, you changed the keys from Symbol to String. Also, your new method returns the value of @content[41..46].strip.to_i (the last value of the method), whereas your old method returns the entire Hash. That could cause issues as well. Since your attributes returns a Fixnum, you might get NoMethodError: undefined method 'stringify_keys' for Fixnum because of it. Fix by return test or just test on the last line of your method. — Daniël Knippers
– Daniël Knippers, Commented May 6, 2014 at 8:20

xdazz · Accepted Answer · 2014-05-06 08:22:34Z

3

The key is symbol in your first piece of code, and you have to return test at last in your second piece of code.

def attributes
  test = {}
  test[:city]          = @content[1..20].strip
  test[:streetname]    = @content[21..40].strip
  test[:house_number]  = @content[41..46].strip.to_i
  test
end

answered May 6, 2014 at 8:22

xdazz

161k38 gold badges255 silver badges278 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Robin van Dijk Over a year ago

Wow thanks, calling test on the last line fixed this after already changing the keys from a string back to a symbol, as stated by @Monk_Code and @Daniël Knippers. Could you explain why calling test again is required for it to work?

xdazz Over a year ago

@RobinvanDijk test at last is same as return test, ruby will return last evaluated expression.

Roman Kiselenko · Accepted Answer · 2014-05-06 08:29:10Z

1

In Rails with active support you can use symbolize_keys and stringify_keys look example:

  => hash = {"foo"  => 1, 'baz' => 13}
  => {"foo"=>1, "baz"=>13}
  => hash.symbolize_keys
  => {:foo=>1, :baz=>13}

and back:

  => hash.symbolize_keys.stringify_keys
  => {"foo"=>1, "baz"=>13}

answered May 6, 2014 at 8:29

Roman Kiselenko

44.5k9 gold badges100 silver badges111 bronze badges

Collectives™ on Stack Overflow

Stringify keys error when building a hash

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related