Bit array implementation in javascript using Uint8Array

BitArray.js

class BitArray {
	/**
	 * BitArray: Every element is 1 bit in size.
	 * 
	 * @param {number} size Size of the BitArray
	 * @param {0|1} initialValue Initialize BitArray with `initialValue` (default: `0`)
	 */
	constructor(size, initialValue = 0) {
		this._size = Math.ceil(size / 8);
		this._array = new Uint8Array(this._size); // Default initialized with 0
		if (initialValue) this._array.fill(255);
	}

	/**
	 * @param {number} bitIndex Index of BitArray
	 * @param {0|1} bitValue Value to be set at `bitIndex` (default: `1`)
	 */
	set(bitIndex, bitValue = 1) {
		// Ignore out of bound index
		if (bitIndex >= this._size * 8) return;

		const index = Math.floor(bitIndex / 8);
		const shift = 7 - bitIndex % 8;

		if (bitValue) this._array[index] |= 1 << shift;
		else this._array[index] &= ~(1 << shift);
	}

	/**
	 * @param {number} bitIndex Index of BitArray
	 * @returns {0|1} bit value at `bitIndex`
	 */
	get(bitIndex) {
		// Return 0 for out of bound index
		if (bitIndex < 0 || bitIndex >= this._size * 8) return 0;

		const index = Math.floor(bitIndex / 8);
		const shift = 7 - bitIndex % 8;

		const val = this._array[index] & 1 << shift;
		return val >> shift;
	}

	clear() {
		this._array.fill(0);
	}
}