用promise 封裝 ajax（來自牛客）
阿新 • • 發佈：2020-12-06
請使用Promise封裝Ajax操作
原始的Ajax操作如下：
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var onSuccess = function(result){};//成功的回撥
var onFail = function(error){};//失敗的回撥
var req =new XMLHttpRequest();
req.open("POST","www.baidu.com",true);
req.onload = function(){
if(req.readyState ===4 && req.status ===200){
onSuccess(req.response);}else {
onFail(req.statusText);
}
}
req.onerror = function(){
onFail(Error("網路異常"));
}
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constajax=url=>{
returnnewPromise((resolve,reject)=>{letreq=newXMLHttpRequest();
req.open("POST",url,true);
req.onload=()=>{
if(req.readyState===4&&req.status===200){
resolve(req.response);
}else{
reject(req.statusText);
}
}
req.onerror=()=>{
reject(Error("網路異常"));
}
})
}
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