[1、验证邮箱地址唯一性](1%E3%80%81%E9%AA%8C%E8%AF%81%E9%82%AE%E7%AE%B1%E5%9C%B0%E5%9D%80%E5%94%AF%E4%B8%80%E6%80%A7.md) [2、搜索框内容自动提示](2%E3%80%81%E6%90%9C%E7%B4%A2%E6%A1%86%E5%86%85%E5%AE%B9%E8%87%AA%E5%8A%A8%E6%8F%90%E7%A4%BA.md) [3、省市区三级联动](3%E3%80%81%E7%9C%81%E5%B8%82%E5%8C%BA%E4%B8%89%E7%BA%A7%E8%81%94%E5%8A%A8.md) [4、案例:腾讯天气](4%E3%80%81%E6%A1%88%E4%BE%8B%E8%85%BE%E8%AE%AF%E5%A4%A9%E6%B0%94.md)