In this post, I have listed several methods to generate a random number. However, sometimes you can see people using a random seed to generate one.
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Why need a seed to create a random number?
Quick answer: if you want to have control to the random sequence or let other people to generate the same sequence of random numbers, take a seed.
We should know that a random number generated by computer is based on some algorithm written by programmers. It means that it is not 100% random like the random process that you find in nature. In another word, we call it pseudo-random.
The random generator is somehow complicated, but for demo purposes, I assume that:
$$aRan_{i} = seed + X_{i}.$$
So if you select the same seed, then you can have the same sequence.
Random seed in Python.
1 2 3 4 | import random random.seed(10) print([random.randint(0, 9) for _ in range(5)]) |
if you run the code , you will always have the same sequence as mine:
1 | [5, 4, 5, 2, 8] |
Random seed in C#
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | using System; public class Program { public static void Main() { Console.WriteLine("Hello World"); Random rdm = new Random(4);//seed = 4 for(int i = 0; i < 5; i++){ Console.Write(rdm.Next(9)+ " "); } } } |
And similarly, we have the same sequence :
1 | 7 8 5 3 0 |
Tung Nguyen
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