Vector3D.this C# (CSharp) Method

    public double this[int index]
    {
        get
        {
            switch (index)
            {
            case 0:
                return this.x;
            case 1:
                return this.y;
            case 2:
                return this.z;
            default:
                throw new IndexOutOfRangeException ("Invalid Vector3D index!");
            }
        }
        set
        {
            switch (index)
            {
            case 0:
                this.x = value;
                break;
            case 1:
                this.y = value;
                break;
            case 2:
                this.z = value;
                break;
            default:
                throw new IndexOutOfRangeException ("Invalid Vector3D index!");
            }
        }
    }