[【1】跨域](%E3%80%901%E3%80%91%E8%B7%A8%E5%9F%9F.md) [【2】状态码](%E3%80%902%E3%80%91%E7%8A%B6%E6%80%81%E7%A0%81.md) [【3】get和post的区别](%E3%80%903%E3%80%91get%E5%92%8Cpost%E7%9A%84%E5%8C%BA%E5%88%AB.md) [【4】页面优化](%E3%80%904%E3%80%91%E9%A1%B5%E9%9D%A2%E4%BC%98%E5%8C%96.md)