Clojure Programming/Examples/API Examples/Data Structures

Numbers Computation + Returns the sum of nums. (+) returns 0. (+ [] [x] [x y] [x y & more]) user=> (+ 1 2 3) 6 user=> (map + [1 2 3] [1 1 2]) (2 3 5) - If no ys are supplied, returns the negation of x, else subtracts the ys from x and returns the result. (- [x] [x y] [x y & more]) user=> (- 1 2 3) -4 user=> (- -1) 1 * Returns the product of nums. (*) returns 1. (* [] [x] [x y] [x y & more]) user=> (* 1 2 3 4) 24 / If no denominators are supplied, returns 1/numerator, else returns numerator divided by all of the denominators. (/ [x] [x y] [x y & more]) user=> (/ 1 4) 1/4 inc Returns a number one greater than num. (inc [x]) user=> (inc 41) 42 user=> (inc 1/4) 5/4 dec Returns a number one less than num. (dec [x]) user=> (dec 99) 98 user=> (map dec [2 3 4]) (1 2 3) min Returns the least of the nums. (min [x] [x y] [x y & more]) user=> (min 2 -1 3) -1 max Returns the greatest of the nums. (max [x] [x y] [x y & more]) user=> (max 2 -1 3) 3 quot Quotient of dividing numerator by denominator. (quot [num div]) user=> (quot 4 2) 2 user=> (quot 5 2) 2 user=> (quot 6 2) 3 rem Remainder of dividing numerator by denominator. (rem [num div]) user=> (rem 5 2) 1 user=> (rem 4 2) 0 rationalize Returns the rational value of num. (rationalize [num]) user=> (rationalize 1.33) 133/100 user=> (rationalize 3.14159265) 62831853/20000000 user=> (rationalize (Math/sqrt 2)) 14142135623730951/10000000000000000 Comparison == Returns non-nil if nums all have the same value, otherwise false. (== [x] [x y] [x y & more]) user=> (== (+ 1 2) 3) true user=> (== (+ 1 2) 3 2.999) false user=> (if (== 2 (+ 1 1)) (println "So easy!")) So easy! user=> (== true true) ;Be careful! Works only for nums. false user=> (= true true) ;= works like Java x.equals(y) true < Returns non-nil if nums are in monotonically increasing order, otherwise false. (< [x] [x y] [x y & more]) user=> (< 1 (Math/sqrt 2) (+ 1 1)) true user=> (< 5 5) false user=> (< 5) true > Returns non-nil if nums are in monotonically decreasing order, otherwise false. (> [x] [x y] [x y & more]) user=> (> 7 6 4 2) true user=> (> 2 4) false <= Returns non-nil if nums are in monotonically non-decreasing order, otherwise false. (<= [x] [x y] [x y & more]) user=> (<= 0 1 1) true >= Returns non-nil if nums are in monotonically non-increasing order, otherwise false. (>= [x] [x y] [x y & more]) user=> (>= 3 2 1) true Predicates zero? Returns true if num is zero, else false. (zero? [x]) user=> (zero? 0.01) false user=> (zero? 0) true pos? Returns true if num is greater than zero, else false. (pos? [x]) user=> (pos? 0) false user=> (pos? (Math/PI)) true user=> (filter pos? [-1 1 0 -1 5 2]) (1 5 2) neg? Returns true if num is less than zero, else false. (neg? [x]) user=> (neg? -1) true user=> (neg? 0) false Strings str user=> (str "a" :b \c 3 4.5 6/7) "a:bc34.56/7" user=> (str [1 2]) "[1 2]" user=> (str 1 2) "12" user=> (str #(1)) "user$eval__1289$fn__1291@4f53dd" Characters user=> \a \a user=> (seq "a") \a user=> (seq " ") (\space) user=> (char 13) \return user=> (str \a \b \c) "abc" user=> (char? \z) true