CODEWITHSUNDEEP
rubyhash
Richard
Richard

Reputation: 65540

Use capitalized hash keys in a map?

I'm trying to create some sample data:

1.upto(19).map {|n| { Keyword: "some-term-#{n}", TotalSearches: n } }

But the data that comes back has slightly different hash keys:

[{:Keyword=>"some-term-1", :TotalSearches=>1}, ...

How can I force it to use the hash keys I specified, like this?

[{"Keyword"=>"some-term-1", "TotalSearches"=>1}, ...

If I put quotes around the hash keys:

1.upto(19).map {|n| { "Keyword": "some-term-#{n}", "TotalSearches": n } }

I get an error.

Upvotes: 0

Views: 425

Answers (1)

tadman
tadman

Reputation: 211610

There's two notations for Ruby hashes.

The first is the traditional notation:

{ :key => "value" }
{ "key" => "value" }

The new notation looks more like JavaScript and others:

{ key: "value" }

This is equivalent to the traditional notation { :key => "value } which is how it shows up in inspect mode, so don't worry if the presentation changes, it's actually the same thing. The new notation forces the use of symbol keys.

If you want to use string keys you need to use the traditional notation.

It's worth noting you can mix and match in the same definition:

{ key: "value", "Key" => "value" }

Ruby encourages the use of symbol keys in cases where the keys are predictable and used frequently. It discourages symbol keys when you're dealing with arbitrary user data such as parameters from forms. In that case strings are a better plan.

Upvotes: 4

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