javascript - JS generate random boolean

Question

Simple question, but I'm interested in the nuances here.

I'm generating random booleans using the following method I came up with myself:

const rand = Boolean(Math.round(Math.random()));

Whenever random() shows up, it seems there's always a pitfall - it's not truly random, it's compromised by something or other, etc. So, I'd like to know:

a) Is the above the best-practice way to do it?

b) Am I overthinking things?

c) Am I underthinking things?

d) Is there a better/faster/elegant-er way I don't know of?

(Also somewhat interested if B and C are mutually exclusive.)

Update

If it makes a difference, I'm using this for movement of an AI character.

Answer 1

You can compare Math.random() to 0.5 directly, as the range of Math.random() is [0, 1) (this means 'in the range 0 to 1 including 0, but not 1'). You can divide the range into [0, 0.5) and [0.5, 1).

var random_boolean = Math.random() < 0.5;

// Example
console.log(Math.random() < 0.1); //10% probability of getting true
console.log(Math.random() < 0.4); //40% probability of getting true
console.log(Math.random() < 0.5); //50% probability of getting true
console.log(Math.random() < 0.8); //80% probability of getting true
console.log(Math.random() < 0.9); //90% probability of getting true