weighted-list

A small package with the concept of weighted list, where you can get items sorted by weight but also get a weighted random item

Installation

npm install --save weighted-list

Usage

WeigtedList is a super set of the JavaScript Set Object which enables you to reach all of its method. Upon that the add method now takes both the value to store, but also an optional weight. There's also methods to sort by the weight (either descending or ascending) as well as receiving a weighted random object out of the set.

Add

const WeightedList = require("weighted-list");

const weightedList = new WeightedList();

weightedList.add("Beef", 8);
weightedList.add("Vegetables", 2);
weightedList.add("Wine", 10);

fromArray

You can also batch insert data from an array. Either as objects with key and weight or as single strings which will get the default weight (1).

const WeightedList = require("weighted-list");
const fruits = [
  { key: "orange", weight: 10 },
  { key: "banana", weight: 2 },
  { key: "apple", weight: 5 }
];

const weightedList = new WeightedList();
weightedList.fromArray(fruits);

Sort

const descendingSet = weightedList.sort(); // Descending is default, can also be set by DESC
const listDesc = Array.from(descendingSet);
listDesc.forEach(item => {
  console.log(`${item.key} has the weight ${item.weight}`);
});

Results in

Wine has the weight 10
Beef has the weight 8
Vegetables has the weight 2

const ascendingSet = weightedList.sort("ASC");
const listAsc = Array.from(ascendingSet);
listAsc.forEach(item => {
  console.log(`${item.key} has the weight ${item.weight}`);
});

Results in

Vegetables has the weight 2
Beef has the weight 8
Wine has the weight 10

Random

weightedList.random();

Which will most often give you Wine as it is the one with highest weight and so on.