clojure.core/with-out-str

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Type: macro Added: Clojure 1.0 Examples: 4 Runnable: 2

([& body])

Evaluates exprs in a context in which out is bound to a fresh StringWriter. Returns the string created by any nested printing calls.

Examples

by gstamp on 2010-08-04 ▶

;; Instead of printing, the following will place the output normally ;; sent to stdout into a string. (with-out-str (println "this should return as a string")) "this should return as a string\n"

by viebel on 2016-03-25 ▶

;; `time` prints the elapsed time. `with-out-str` can put it into a variable. (def elapsed (with-out-str (time (last (range 10000))))) elapsed ;=> "\"Elapsed time: 49.363055 msecs\"\n"

by ertugrulcetin on 2017-04-30 . May have evaluation errors. ▶

(defmacro with-out-str-data-map [& body] `(let [s# (new java.io.StringWriter)] (binding [*out* s#] (let [r# ~@body] {:result r# :str (str s#)})))) (with-out-str-data-map (do (println "Clojure is the best!") 2)) ;;=> {:str "Clojure is the best!\n", :result 2}

by yogsototh on 2017-09-05 . May have evaluation errors. ▶

(defn pp-str [x] (with-out-str (clojure.pprint/pprint x)) (pp-str {:foo "foo" :bar "bar"}) ;;=> "{:foo \"foo\", :bar \"bar\"}\n"

See also

• clojure.core/with-in-str

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