June 2018 Update

Task/Pick-random-element/BASIC/pick-random-element-2.basic

@@ -0,0 +1,8 @@
+10 DIM A$(9)
+20 FOR I=0 TO 9 : READ A$(I) : NEXT
+30 X = RND(-TI) : REM 'PLANT A RANDOM SEED'
+40 X = INT(RND(1)*10)
+50 PRINT A$(X)
+60 END
+100 DATA ALPHA, BRAVO, CHARLIE, DELTA, ECHO
+110 DATA FOXTROT, GOLF, HOTEL, INDIA, JULIETT

Task/Pick-random-element/Haskell/pick-random-element-1.hs

@@ -3,4 +3,4 @@ import System.Random (randomRIO)
 pick :: [a] -> IO a
 pick xs = fmap (xs !!) $ randomRIO (0, length xs - 1)
 
-x <- pick [1 2 3]
+x <- pick [1, 2, 3]

Task/Pick-random-element/Haskell/pick-random-element-2.hs

@@ -1,5 +1,2 @@
 import Data.Random
-import Data.Random.Source.DevRandom
-import Data.Random.Extras
-
-x <- runRVar (choice [1 2 3]) DevRandom
+sample $ randomElement  [1, 2, 3]

Task/Pick-random-element/Haskell/pick-random-element-3.hs

@@ -1,3 +1,3 @@
-import Test.QuickCheck (generate, elements)
-
-x <- (generate . elements) [1, 2, 3]
+do
+  x <- sample $ randomElement  [1, 2, 3]
+  print x

Task/Pick-random-element/Kotlin/pick-random-element.kotlin

@@ -1,13 +1,30 @@
-// version 1.0.6
+// version 1.2.10
+
+import java.util.Random
+
+/**
+ * Extension function on any list that will return a random element from index 0
+ * to the last index
+ */
+fun <E> List<E>.getRandomElement() = this[Random().nextInt(this.size)]
+
+/**
+ * Extension function on any list that will return a list of unique random picks
+ * from the list. If the specified number of elements you want is larger than the
+ * number of elements in the list it returns null
+ */
+fun <E> List<E>.getRandomElements(numberOfElements: Int): List<E>? {
+    if (numberOfElements > this.size) {
+        return null
+    }
+    return this.shuffled().take(numberOfElements)
+}
 
 fun main(args: Array<String>) {
     val list = listOf(1, 16, 3, 7, 17, 24, 34, 23, 11, 2)
-    println("The list consists of the following numbers:")
-    println(list)
-    val chosen = mutableSetOf<Int>()
-    println("\nFive elements chosen at random without duplication are:")
-    while (chosen.size < 5) {
-        val r = list[(Math.random() * list.size).toInt()]
-        if (chosen.add(r)) println(r)
-    }
+    println("The list consists of the following numbers:\n${list}")
+
+    // notice we can call our extension functions as if they were regular member functions of List
+    println("\nA randomly selected element from the list is ${list.getRandomElement()}")
+    println("\nA random sequence of 5 elements from the list is ${list.getRandomElements(5)}")
 }

Task/Pick-random-element/Nim/pick-random-element.nim

@@ -1,14 +1,4 @@
-import math
 randomize()
 
-proc random[T](a: openarray[T]): T =
-  a[random(a.low..a.len)]
-
 let ls = @["foo", "bar", "baz"]
-echo ls.random()
-
-var xs: array[10..14, string]
-for i in 10..14:
-  xs[i] = "foo: " & $i
-
-echo xs.random()
+echo ls.rand()

Task/Pick-random-element/Perl-6/pick-random-element-2.pl6

@@ -1,3 +1,3 @@
-(1..6).roll;    # return 1 random value in the range 1 through 6
-(1..6).roll(3); # return a list of 3 random values in the range 1 through 6
-(1..6).roll(*); # return a lazy infinite list of random values in the range 1 through 6
+say (1..6).roll;          # return 1 random value in the range 1 through 6
+say (1..6).roll(3);       # return a list of 3 random values in the range 1 through 6
+say (1..6).roll(*)[^100]; # return first 100 values from a lazy infinite list of random values in the range 1 through 6

Task/Pick-random-element/Perl-6/pick-random-element-3.pl6

@@ -1,5 +1,5 @@
 # define the deck
 my @deck = <2 3 4 5 6 7 8 9 J Q K A> X~ <♠ ♣ ♥ ♦>;
-@deck.pick;    # Pick a card
-@deck.pick(5); # Draw 5
-@deck.pick(*); # Get a shuffled deck
+say @deck.pick;    # Pick a card
+say @deck.pick(5); # Draw 5
+say @deck.pick(*); # Get a shuffled deck

Task/Pick-random-element/Red/pick-random-element.red

@@ -0,0 +1 @@
+>> random/only collect [repeat i 10 [keep i]]

Task/Pick-random-element/Ring/pick-random-element.ring

@@ -1,6 +1,6 @@
 aList  = "abcdefghij"
 for i = 1 to 10
-    letter = random(10)
+    letter = random(9) + 1
     if letter > 0
        see aList[letter] + nl
     ok

Task/Pick-random-element/Ruby/pick-random-element.rb

@@ -1,4 +1,2 @@
-irb(main):001:0> %w(north east south west).sample
-=> "west"
-irb(main):002:0> (1..100).to_a.sample(2)
-=> [17, 79]
+%w(north east south west).sample   # => "west"
+(1..100).to_a.sample(2)            # => [17, 79]

Task/Pick-random-element/Rust/pick-random-element.rust

@@ -1,6 +1,10 @@
 extern crate rand;
+
 use rand::Rng;
+
 fn main() {
     let array = [5,1,2,5,6,7,8,1,2,4,5];
-    println!("{}", rand::thread_rng().choose(&array).unwrap());
+    let mut rng = rand::thread_rng();
+
+    println!("{}", rng.choose(&array).unwrap());
 }

Task/Pick-random-element/VBA/pick-random-element.vba

@@ -0,0 +1,10 @@
+Option Explicit
+
+Sub Main_Pick_Random_Element()
+    Debug.Print Pick_Random_Element(Array(1, 2, 3, 4, 5, #11/24/2017#, "azerty"))
+End Sub
+
+Function Pick_Random_Element(myArray)
+    Randomize Timer
+    Pick_Random_Element = myArray(Int((Rnd * (UBound(myArray) - LBound(myArray) + 1) + LBound(myArray))))
+End Function