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      nth

      clojure.core

      Available since 1.0 (source)
      • (nth coll index)
      • (nth coll index not-found)
      Returns the value at the index. get returns nil if index out of
bounds, nth throws an exception unless not-found is supplied.  nth
also works for strings, Java arrays, regex Matchers and Lists, and,
in O(n) time, for sequences.
      © Rich Hickey. All rights reserved. Eclipse Public License 1.0
      2 Examples
      ; Note that nth uses zero-based indexing, so that
;   (first my-seq) <=> (nth my-seq 0)
(def my-seq ["a" "b" "c" "d"])
(nth my-seq 0)
; => "a"
(nth my-seq 1)
; => "b"
(nth [] 0)
; => IndexOutOfBoundsException ...
(nth [] 0 "nothing found")
; => "nothing found"
(nth [0 1 2] 77 1337)
; => 1337
      (nth ["last"] -1 "this is not perl")
; => "this is not perl"
      See Also
      clojure.core/first

      Returns the first item in the collection. Calls seq on its argument. If coll is nil, returns nil...

      Added by Havvy
      clojure.core/second

      Same as (first (next x))

      Added by Havvy
      clojure.core/nthnext

      Returns the nth next of coll, (seq coll) when n is 0.

      Added by Havvy
      clojure.core/get

      Returns the value mapped to key, not-found or nil if key not present in associative collection, se...

      Added by jw0
      clojure.core/take-nth

      Returns a lazy seq of every nth item in coll. Returns a stateful transducer when no collection is...

      Added by MicahElliott
      clojure.core/nthrest

      Returns the nth rest of coll, coll when n is 0.

      Added by MicahElliott
      clojure.core/rand-nth

      Return a random element of the (sequential) collection. Will have the same performance characteris...

      Added by MicahElliott
      2 Notes
        By , created 8.5 years ago

        Rather than throwing an exception, (nth nil n) returns nil for any number n.

        By , created 5.9 years ago

        Floats are treated as indexes (nth [0 1] 1.9) returns the element at index 1. At first glance it may seem as though they are always rounded down. However due to floating point precision (nth [0 1] 1.9999999999999999) will raise an IndexOutOfBoundsException.