如何将新的 Object 添加到空数组并在终端中显示

Question

谁能帮我弄清楚如何将 newUser Object 添加到一个名为 users 的空数组中？ 当我运行 console.log(users) 时，我使用 req.body 内部的 POSTMAN 发送的数据未显示在终端中

   let users = [];
   app.post("/signup", (req, res) => {
     let username = req.body.username;
     let password = req.body.password;
     /* typeof and undefined is added for the scenario 
        if the request body has either username or password object only;
        OR any isn't declared in the request body. */

     if (username !== null &&
       username !== "" &&
       typeof username !== "undefined" &&
       password !== null &&
       password !== "" &&
       typeof password !== "undefined") {

       let requestBody = "";
       req.on("data", (addUser) => {
         requestBody += addUser;
       });
       req.on("end", () => {
         requestBody = JSON.parse(requestBody);
         let newUser = {
           "username": requestBody.username,
           "password": requestBody.password
         }
         users.push(newUser);
         console.log(users);
       });

       res.send(`User ${username} successfully registered`);
     } else {
       res.send(`Please input both username and password.`);
     }
   });

Answer 1

来自快递文件

请求正文

包含在请求正文中提交的数据键值对。 默认情况下，它是未定义的，并且在您使用诸如 express.json() 之类的正文解析中间件时填充

所以你需要在文件顶部的某个地方执行此操作，

app.use(express.json);

另外，使用 express，您不需要使用req.on来解析传入的数据，您可以简单地执行以下操作，

   let users = [];
   app.post("/signup", (req, res) => {
     let username = req.body.username;
     let password = req.body.password;
     /* typeof and undefined is added for the scenario 
        if the request body has either username or password object only;
        OR any isn't declared in the request body. */

     if (username !== null &&
       username !== "" &&
       typeof username !== "undefined" &&
       password !== null &&
       password !== "" &&
       typeof password !== "undefined") {

       users.push({
         username,
         password
       });
       console.log(users);

       res.send(`User ${username} successfully registered`);
     } else {
       res.send(`Please input both username and password.`);
     }
   });

这是您在repl.it上的示例