上demo小案例
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<input type="" name="" value="" id='nameTest'>
<input type="button" value="发送ajax请求" id='btnAjax'>
</body>
</html>
<script type="type/javascript">
document.querySelector("#btnAjax").onclick=function(){
//创建ajax
var ajax=new XMLHttpRequest();
//设置ajax 的url
//获取标签的值
var username=document.querySelector("#nameTest").value;
ajax.open('get','ajax.php?name='+username);
ajax.send();
ajax.onreadystatechange=function(){
if(ajax.readyState==4 && ajax.status==200){
console.log(ajax.responseText);
}
}
}
</script>
调用PHP文件路径
<?php echo $_GET['name'].'这道菜好吃' ?>