Here's a super compact vector class that supports multiple dimensions

CVector.js

		class CVector {
			constructor(components = []) { this.components = components; }
			get lengthSquared() { return this.components.reduce((p, c) => p + c * c); }
			get length() { return Math.sqrt(this.lengthSquared); }
			get normalized() { return new CVector(this.components.map(x => x / this.length)); }
			get sum() { return Math.sum(this.components); }
			add(other, missingComponentValue = 0) { return this._zip(other, (a, b) => a + b, missingComponentValue); }
			sub(other, missingComponentValue = 0) { return this._zip(other, (a, b) => a - b, missingComponentValue); }
			mul(other, missingComponentValue = 1) { return this._zip(other, (a, b) => a * b, missingComponentValue); }
			div(other, missingComponentValue = 1) { return this._zip(other, (a, b) => a / b, missingComponentValue); }
			dist(other, missingComponentValue = 0) { return this.sub(other).length }
			lerp(other, p) { return this._zip(other, (a, b) => a * p + b * (1 - p)); }
			lerpScalar(other, p) { return this.lerp(other, p / this.dist(other)); }
			clamp(min, max) { return this._zip(min, Math.min)._zip(max, Math.max); }
			clampLength(min, max) { return this.mul(new CVector(), Math.max(min, Math.min(max, this.length)) / this.length) };
			cross(other) { return this._rol(1).mul(other); }
			dot(other) { return this.mul(other).sum; }
			_rol(n = 1) { return new CVector(this.components.splice(n).concat(this.components.splice(0, n))); }
			_zip(other, fn = (a, b) => [a, b], missingComponentValue = NaN) {
				let cA = this.components, cB = other.components, diff = cA.length - cB.length;
				if (diff != 0) {
					const filler = new Array(Math.abs(diff)).fill(missingComponentValue);
					if (diff < 0) {
						cA = cA.concat(filler);
					} else if (diff > 0) {
						cB = cB.concat(filler);
					}
				}
				return new CVector(cA.map((x, i) => fn(x, cB[i])));
			}
		}