Create multi-dimensional array with a useful getter and setter

README.md

Usage

let arr = new dimArray([3, 3, 3], Array(3 * 3 * 3).fill(0).map((_, i) => i));

Properties

arr.dimensionCount //=> 3
arr.size           //=> 27
arr.values         //=> [ [ [0, 1, 2], [3, 4, 5], [6, 7, 8] ], [ [9, 10, 11], [12, 13, 14], [15, 16, 17] ], [ [18, 19, 20], [21, 22, 23], [24, 25, 26] ] ]
[...arr]           //=> [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26 ]

Methods

arr.get(1, 0, 2)      //=> 10
arr.set(1, 0, 2, 27);
arr.get(1, 0, 2)      //=> 27

TODO

• override array functions
  • map
  • find
  • some
  • keys => how
  • join => how?
  • every
  • slice
  • filter
  • forEach
  • includes

multi-dimensional-array.js

class dimArray {
  #dims;
  #values;

  [Symbol.iterator]() {
    return this.#values.values();
  }

  get size() {
    return this.#dims.reduce((a, c) => a * c, 1);
  }

  get dimensionCount() {
    return this.#dims.length;
  }

  get values() {
    let ref;
    let values = this.#values.slice(0);
    this.#dims.forEach((dimSize, i) => {
      if (i === this.#dims.length - 1) { return; }
      ref = values;
      values = [];
      while (ref.length) {
        values.push(ref.splice(0, dimSize));
      }
    });
    return values;
  }

  set values(vals) {
    if (!Array.isArray(vals)) {
      throw Error(`The values variable should be of type 'array', not '${typeof vals}'.`);
    }
    if (vals.length !== this.size) {
      throw Error(`Based on the dimensions, the value array should contain ${this.size} item${this.size === 1 ? '' : 's'}, not ${vals.length}.`);
    }
    this.#values = vals;
  }

  get(...args) {
    return this.#values[this.getIndex(...args)];
  }

  set(...args) {
    this.#values[this.getIndex(...args.slice(0, -1))] = args.pop();
  }

  getIndex(...args) {
    if (args.length !== this.#dims.length) {
      throw Error(`${args.length} arguments were passed to get but there are ${this.#dims.length} dimensions.`);
    }
    let index = 0;
    let multiplier = 1;
    args.slice(0).reverse().forEach((arg, i) => {
      index += arg * multiplier;
      multiplier *= this.#dims[i];
    });
    return index;
  }

  constructor(dimensionDistribution=[1], initialValues=[]) {
    this.#dims = dimensionDistribution;
    this.values = initialValues;
  }
}