everyutil/number/weightedRandom.js

A comprehensive library of lightweight, reusable utility functions for JavaScript and TypeScript, designed to streamline common programming tasks such as string manipulation, array processing, date handling, and more.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.weightedRandom = void 0;
/**
 * Returns a random choice from the input choices array, using the given weights.
 * @author @dailker
 * @param {number[]} choices - The array of possible choices.
 * @param {number[]} weights - The array of weights corresponding to each choice.
 * @returns {number} A randomly selected value from choices, weighted by weights.
 */
function weightedRandom(choices, weights) {
    const sum = weights.reduce((a, b) => a + b, 0);
    let r = Math.random() * sum;
    for (let i = 0; i < choices.length; i++) {
        if (r < weights[i])
            return choices[i];
        r -= weights[i];
    }
    return choices[choices.length - 1];
}
exports.weightedRandom = weightedRandom;