Logo

Programming-Idioms

# 69 Seed random generator
Use seed s to initialize a random generator.

If s is constant, the generator output will be the same each time the program runs. If s is based on the current value of the system clock, the generator output will be different each time.
New implementation

Be concise.

Be useful.

All contributions dictatorially edited by webmasters to match personal tastes.

Please do not paste any copyright violating material.

Please try to avoid dependencies to third-party libraries and frameworks.

Other implementations 
with Ada.Numerics.Discrete_Random;
declare
   Package Rand is new Ada.Numerics.Discrete_Random (Integer);
   Gen : Rand.Generator;
begin
   Rand.Reset (Gen, Initiator => S);
end;
#include <stdlib.h>
srand(s);
#include <stdlib.h>
srand(s);
using System;
var random = new Random(s);
std.random, std.stdio;
auto s = 8;
auto gen = Random(s);
writeln(gen.front);
import "dart:math";
var r = new Random(s);

  call random_seed(size = n)
  allocate(seed(n))
  ! ...
  call random_seed(put=seed)

import "math/rand"
rand.Seed(s)
import "math/rand"
r := rand.New(rand.NewSource(s))
System.Random.mkStdGen s

const seed = require ('seedrandom')
seed (s)
import java.util.Random;
Random r = new Random(s);
val random = Random(seed=s)
call random_seed (put=s)
math.randomseed(s)
srand($s);
var
  SomeInteger: Integer;
  Value: double;
begin
  ...
   //initializes the PRNG's seed with a value depensing on system time
  Randomize; 
  Value := random;
  ...
   //Output will be the same eacht time the program runs
  RandSeed := SomeInteger; 
  Value := random;
...
end.
srand($s);
import random
rand = random.Random(s)
r = Random.new(s)
use rand::{Rng, SeedableRng, rngs::StdRng};
let s = 32;
let mut rng = StdRng::seed_from_u64(s);

Preview