正在跳转至 https://anran758.github.io/blog/2017/12/26/%E6%96%B0%E6%89%8B%E4%B8%8D%E7%9F%A5%E9%81%93%E7%9A%84%E6%8A%80%E5%B7%A7-if%E8%AF%AD%E5%8F%A5%E7%9A%84%E5%88%A4%E5%AE%9A/#%E5%BC%80%E5%A7%8B