jsonp 的原理？

个人理解：动态创建script标签，利用src进行传值
实例：
//截取的淘宝数据，模仿百度搜索页面，可进行搜索

复制代码并运行可显示效果
<style>
	*{padding: 0;margin: 0;}
	ul{
		list-style:none;
		border:1px solid #ccc;
		display:none;
		padding-left:10px;
	}
	a{
		text-decoration:none;
		color:gray;
		display:block;
		width:400px;
		height:30px;
		text-align:left;
	}
	a:hover{
		background:#add8e6;
	}
	.wrap{
		width:400px;
		height:auto;
		margin:0px auto;
		text-align:center;
		margin-top:80px;
	}
	.wrap img{
		width:270px;
		height:130px;
	}
	.wrap input{
		width:400px;
		height:30px;
		line-height:30px;
		text-indent:1em;
		outline:none;
		border:none;
		border:1px solid gray;
	}
</style>

<div class="wrap">
	<img src="https://www.baidu.com/img/bd_logo1.png?where=super" alt="">
	<input type="text" id="txt">
	<ul id="list">
		<li><a href="##">爱奇艺</a></li>
		<li><a href="##">爱土豆</a></li>
		<li><a href="##">阿里巴巴</a></li>
	</ul>
</div>
<script>
	function getData(data){
		var olist = document.getElementById("list");
		var html = "";
		for(var i=0;i<data.s.length;i++){
			html += '<li><a href="https://ww.baidu.com/s?wd = '+data.s[i]+'">'+data.s[i]+'</a></li>';
		}
		olist.innerHTML = "";
		olist.innerHTML = html;
	}
	var otxt = document.getElementById("txt");
	otxt.onkeyup = function(){
		var olist = document.getElementById("list");
		olist.style.display = "block";
		var oScript = document.createElement("script");
		oScript.src = "https://sp0.baidu.com/5a1Fazu8AA54nxGko9WTAnF6hhy/su?wd = "+otxt.value+"&cb=getData";
		document.body.appendChild(oScript);
	}