clojure.core/type

View this page on ClojureDocs

Type: function Added: Clojure 1.0 Examples: 2 Runnable: 0

([x])

Returns the :type metadata of x, or its Class if none

Examples

by belun on 2010-09-13 . May have evaluation errors. ▶

;; Checking numbers (type 10) java.lang.Long (type 10.0) java.lang.Double (type nil) nil ;; Checking collections (type [10 20]) clojure.lang.PersistentVector (type '(10 20)) clojure.lang.PersistentList ;; Checking other, but somewhat intuitive, forms (type "A string") java.lang.String (type :a) clojure.lang.Keyword (type Thread) java.lang.Class ;; Checking a symbol (type 'whatever) clojure.lang.Symbol ;; A surprise attack yields (type clojure.lang.Symbol) ;; not such a surprising response java.lang.Class ;; Checking a function (defn foo [] ("any string")) #'user/foo (type foo) user$foo ;; Checking a macro (type clojure.core/fn) java.lang.Exception: Can't take value of a macro: #'clojure.core/fn (NO_SOURCE_FILE:94)

by shuaybi on 2011-05-16 . May have evaluation errors. ▶

;This example demonstrates how to add type information to regular clojure maps (defn purchase-order [id date amount] ^{:type ::PurchaseOrder} ;metadata {:id id :date date :amount amount}) (def my-order (purchase-order 10 (java.util.Date.) 100.0)) my-order => {:id 10, :date #<Date Sun May 15 14:29:19 EDT 2011>, :amount 100.0} (type my-order) => PurchaseOrder

See also

• clojure.core/class (1)
• clojure.core/supers (0)
• clojure.core/instance? (0)

---

Content from the matching ClojureDocs page, with authors credited on each contribution.