我覺得這個沒有什么可糾結吧，每個人可以自己的邏輯，老師講的是他自己的邏輯，最終結果一樣應該就行，比如我自己寫的就跟老師的不同。重在理解吧

const?http?=?require('http');
const?fs?=?require('fs');
const?querystring?=?require('querystring');

const?registeredUserInfos?=?{};
http.createServer((req,?resp)?=>?{
????if?(req.method?==?'GET')?{
????????fs.readFile(`./${req.url}`,?(err,?data)?=>?{
????????????if?(err)?{
????????????????resp.writeHead(404);
????????????????resp.end('Page?not?found.');
????????????}?else?{
????????????????resp.end(data);
????????????}
????????});
????}?else?if?(req.method?==?'POST')?{
????????let?data?=?[];
????????
????????req.on('data',?(chunk)?=>?{
????????????data?+=?chunk;
????????});
????????
????????req.on('end',?()?=>?{
????????????let?params?=?querystring.parse(data);
????????????if?(params.action?==?'reg')?{
????????????????if?(registeredUserInfos[params.username])?{
????????????????????resp.writeHead(500);
????????????????????resp.end('Invalid?user?account,?Please?choose?other?to?try.');
????????????????else?{
????????????????????registeredUserInfos[params.username]?=?params;
????????????????????resp.end('Registered?successfully!');
????????????????}
????????????}?else?if?(params.action?==?'login')?{
????????????????if?(!registeredUserInfos[params.username])?{
????????????????????resp.writeHead(500);
????????????????????resp.end('Invalid?user?account,?Please?choose?other?to?try.');
????????????????}?else?{
????????????????????let?userinfo?=?registeredUserInfos[params.username];
????????????????????if?(params.password?==?userinfo.password)?{
????????????????????????resp.end('Login?successfully');
????????????????????}?else?{
????????????????????????resp.end('Invalid?user?password,?Please?choose?other?to?try.');
????????????????????}
????????????????}
????????????}?else?{
????????????????resp.writeHead(500);
????????????????resp.end('Invalid?action,?Please?choose?other?to?try.');
????????????}
????????});
????}
}).listen(3000);