How to achieve secondary linkage with Ajax and PHP

This time I will show you how to achieve secondary linkage with Ajax combined with PHP. What are the precautions for achieving secondary linkage with Ajax combined with PHP? The following is a practical case, let’s take a look.

Use ajax to get data from php

nbsp;html>

 
 <title>Ajax案例一</title>
 <meta>
 
 
 
 <!-- 二级联动 -->
 <select>
 <option>请选择</option>
 <option>山东省</option>
 <option>辽宁省</option>
 <option>吉林省</option>
 </select>
 <select>
 <option>请选择</option>
 </select>
 <script>
 // 1. 为<select>元素绑定onchange事件
 var provinceEle = document.getElementById("province");
 provinceEle.onchange = function(){
 // 将id为city的元素内容清空
 var city = document.getElementById("city");
 var opts = city.getElementsByTagName("option");
 for(var z=opts.length-1;z>0;z--){
  city.removeChild(opts[z]);
 }
  
 // 2. 获取用户当前选择的省份名称
 var province = provinceEle.value;
 // 3. 创建对应的城市列表 - 数组
 var cities = [];
 switch (province){
  case "山东省":
  cities = ["青岛市","济南市","威海市","日照市","德州市"];
  break;
  case "吉林省":
  cities = ["长春市","松原市","吉林市","通化市","四平市"];
  break;
  case "辽宁省":
  cities = ["沈阳市","大连市","铁岭市","丹东市","锦州市"];
  break;
 }
 // 遍历城市列表
 for(var i=0;i<cities.length;i++){
  // 4. 创建<option>元素
  var option = document.createElement("option");
  // 5. 将城市的信息添加到<option>元素上
  var textNode = document.createTextNode(cities[i]);
  option.appendChild(textNode);
  // 6. 将创建的所有<option>元素添加到id为city元素上
  city.appendChild(option);
 }
  
 }
 </script>
 

php:

<?php  // 用于处理客户端请求二级联动的数据
 // 1. 接收客户端发送的省份信息
 $province = $_POST[&#39;provcince&#39;];
 // 2. 判断当前的省份信息,提供不同的城市信息
 switch ($province){
 case &#39;山东省&#39;:
  echo &#39;青岛市,济南市,威海市,日照市,德州市&#39;;
  break;
 case &#39;辽宁省&#39;:
  echo &#39;沈阳市,大连市,铁岭市,丹东市,锦州市&#39;;
  break;
 case &#39;吉林省&#39;:
  echo &#39;长春市,松原市,吉林市,通化市,四平市&#39;;
  break;
 }
 // 服务器端响应的是字符串
?>

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other php Chinese websites related articles!

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