# Idiom #15 Pick uniformly a random integer in [a..b]

Pick a random integer greater than or equals to a, inferior or equals to b. Precondition : a < b.

function pick(a, b) {
return a + Math.floor(Math.random() * (b - a + 1));
}
#include <stdlib.h>
int pick(int a, int b)
{
int upper_bound = b - a + 1;
int max = RAND_MAX - RAND_MAX % upper_bound;
int r;

do {
r = rand();
} while (r >= max);
r = r % max;
return a + r;
}
(+ a (rand-int (- b a)))
#include <random>
std::mt19937 gen;
std::uniform_int_distribution<size_t> uid (a, b);
uid (gen);
using System;
Random r = new Random();
return r.next(a, b + 1);
import std.random;
auto x1 = uniform(a, b+1);
auto x2 = uniform!"[]"(a, b);
import 'dart:math';
int pick(int a, int b) => a + new Random().nextInt(b - a + 1);
a - 1 + :rand.uniform(b-a+1)
:crypto.rand_uniform(a, b)
crypto:rand_uniform(A, B)
real :: c
integer :: res

call random_number(c)
res = int((b-a+1)*c)
import "math/rand"
func pick(a,b int) int {
return a + rand.Intn(b-a+1)
}
import System.Random
let pick (a, b) = randomRIO (a, b) :: IO Integer
in pick (1, 6) >>= print

import java.util.Random;
int pick(int a, int b){
return a + new Random().nextInt(b - a + 1);
}
math.random(a, b)
a+arc4random_uniform(b+1)
rand(\$a, \$b)
Math
var
_a, _b, _r: Integer;
begin
_r := RandomRange(_a, _b);
end;
my (\$min, \$max) = (5, 25);
my \$val = \$min + int(rand(\$max-\$min));
import random
random.randint(a,b)
rand(a..b)
extern crate rand;
use rand::distributions::{IndependentSample, Range};
fn pick(a: i32, b: i32) -> i32 {
let between = Range::new(a, b);
between.ind_sample(&mut rng)
}
use rand::distributions::Uniform;