XMLHttpRequest之onreadystatechange
代码语言：javascript复制function doReq(url, fn){
var req = new XMLHttpRequest();
req.onreadystatechange = function(){
if(this.readyState == XMLHttpRequest.DONE){
return fn(this);
}
}
req.open('GET', url, false);
req.send();
}
var res;
function myreq(xhttp){
try{
switch(xhttp.status){
case 200:
res = xhttp.responseText;
break;
case 404:
throw new Error('404');
break;
case 500:
throw new Error('500');
break;
default:
throw new Error(xhttp.status);
break;
}
}catch(e){
res = e.message;
}
}
doReq('https://www.w3school.com.cn/demo/js/ajax_info.txt', myreq);
console.log(res);本文采用 「CC BY-NC-SA 4.0」创作共享协议，转载请标注以下信息：
原文出处：Yiiven https://cloud.tencent.com/developer/article/2193263
