map.clj

(def d {:name "Ram", :job "Engineer", :age 16})
;=> #'user/d

(:name d)
;=> "Ram"

;; we don't have location as a key in the map
(:location d)
;=> nil

;; You can give a default value to return (as a third parameter) 
;; if the key is not found in the map
(:location d "Bangalore")
;=> "Bangalore"