Use simple records with jsonp (1)

The usage environment of jsonp is generally available for front-end and back-end exchange when logging in or exchanging data in different domains
Principle:
The introduced js can be from different domains, and the js file can be generated from the background
(What is said here is a bit simple, please go there more Find information)

Use DEMO:

html：
//原生js


    <title></title>
    <script type="text/javascript">
    // 得到航班信息查询结果后的回调函数
    var returnjs = function(data){
        alert(data.code);
    };
    // 提供jsonp服务的url地址（不管是什么类型的地址，最终生成的返回值都是一段javascript代码）
    var url = "http://www.return.com/jsonp/get?code=1&callback=returnjs";//数据接收后台
    // 创建script标签，设置其属性
    var script = document.createElement(&#39;script&#39;);
    script.setAttribute(&#39;src&#39;, url);
    // 把script标签加入head，此时调用开始
    document.getElementsByTagName(&#39;head&#39;)[0].appendChild(script);
    </script>

//jQ版



<meta charset="UTF-8">
<title>Insert title here1</title>
<script type="text/javascript" src="jq.js"></script><!-- 记得引入jq -->


<script type="text/javascript">
	jQuery(document).ready(function(){
	   $.ajax({
	        type: "get",
	        async: false,
	        url: "http://www.return.com/jsonp/get?code=1",//数据接收后台
	        dataType: "jsonp",
	        jsonp: "callback",//传递给请求处理程序或页面的，用以获得jsonp回调函数名的参数名(一般默认为:callback)
	        jsonpCallback:"returnjs",//自定义的jsonp回调函数名称，默认为jQuery自动生成的随机函数名，也可以写"?"，jQuery会自动为你处理数据
	        crossDomain:true,
	        success: function(json){
	            alert(json.code);
	        },
	        error: function(){
	            alert(&#39;fail&#39;);
	        }
	    });
	});
</script>

后台PHP：
<?php class jsonp{
	public function get(){
		$code=$_GET[&#39;code&#39;];
		if($code==1){
			$code=2;
		}
		echo &#39;returnjs({"code":"&#39;.$code.&#39;"})&#39;;
	}
}

The above introduces the simple record of using jsonp (1), including the content. I hope it will be helpful to friends who are interested in PHP tutorials.