particle2.ts

class Particle {
  private _alpha: number | undefined;
  private _beta: number | undefined; 

  public get alpha(): number {
    if (this._alpha === undefined) {
      this._alpha = Math.random() > 0.5 ? 2 : 3; 
    }
    return this._alpha; 
  }

  public get beta(): number {
    if (this._beta === undefined) {
      this._beta = Math.random() > 0.5 ? 2 : 3;
    }  
    return this._beta;
  }
}