What are the benefits of using keywords as keys on maps in Clojure?

Question

I noticed that Clojure usually uses keywords as keys on a map, while in other languages ​​that don't have this concept, they usually use strings.

What are the benefits of using keywords instead of strings or other types?

Answer 1

• Keywords are a type of character that is semantically different from strings and a smaller range of represented values. They can take place with names, there are checks on the legal use of namespaces, etc., and therefore, users can be more confident in the EDN keywords, which means what they expect than, for example, JSON with equivalent string keys.
• Keywords are interned, so all instances of the keyword apply the same to the same object. This is useful for, for example, checking equality.
• Keywords are functions that act as getwith themselves as a key argument. This is convenient for cases like "I want the phone number of all these people" - (map :phone-no people)vs.(map #(get % "phone-no") people)

let :

(let[{:keys [foo bar]} {:foo 1 :bar 30}]
  (+ foo bar)) ;;=>31

, :strs.