js獲取HTTP的請求頭信息

http請求頭部信息的獲取方法：

let req = new XMLHttpRequest(); req.open('GET', document.location, false); req.send(null); console.log(req) let content=req.getResponseHeader('content-type')
console.log(content)

var headers = req.getAllResponseHeaders().toLowerCase(); console.log(headers);

 參考連接：https://www.bbsmax.com/A/WpdK0OrzVQ/