cross-product.js

class Vector {
  constructor(...components) {
    this.components = components
  }
  // ...
  
  // 3D vectors only
  crossProduct({ components }) {
    return new Vector(
      this.components[1] * components[2] - this.components[2] * components[1],
      this.components[2] * components[0] - this.components[0] * components[2],
      this.components[0] * components[1] - this.components[1] * components[0]
    )
  }
}

const one = new Vector(2, 1, 1)
const other = new Vector(1, 2, 2)
console.log(one.crossProduct(other))
// Vector { components: [ 0, -3, 3 ] }
console.log(other.crossProduct(one))
// Vector { components: [ 0, 3, -3 ] }