即使使用正确的 .env 文件，我也无法运行我的应用程序

Question

我尝试遵循登录/注册后端的教程，但我不明白为什么我在 4000 端口上获得许可（还尝试了其他端口只是为了确保该端口不是问题）。 这是教程文字

.env 文件（在我的项目中我有正确的密码和用户

`MONGO_URL =
  "mongodb+srv://****:*****@cluster0.nusq9us.mongodb.net/?retryWrites=true&w=majority&appName=Cluster0";
PORT = 4000;`

Index.js代码：

`const express = require("express");
const mongoose = require("mongoose");
const cors = require("cors");
const app = express();
require("dotenv").config(); 
const { MONGO_URL, PORT } = process.env;

mongoose
  .connect(MONGO_URL, {
    useNewUrlParser: true,
    useUnifiedTopology: true,
  })
  .then(() => console.log("MongoDB is  connected successfully"))
  .catch((err) => console.error(err));

app.listen(PORT, () => {
  console.log(`Server is listening on port ${PORT}`);
});

app.use(
  cors({
    origin: ["http://localhost:4000"],
    methods: ["GET", "POST", "PUT", "DELETE"],
    credentials: true,
  })
);

app.use(express.json());`

错误：

`Error: listen EACCES: permission denied 4000;
    at Server.setupListenHandle [as _listen2] (node:net:1855:21)
    at listenInCluster (node:net:1920:12)
    at Server.listen (node:net:2019:5)
    at Function.listen (C:\Users\Gizas\Desktop\Licenta\server\node_modules\express\lib\application.js:635:24)
    at Object.<anonymous> (C:\Users\Gizas\Desktop\Licenta\server\index.js:16:5)
    at Module._compile (node:internal/modules/cjs/loader:1241:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1295:10)
    at Module.load (node:internal/modules/cjs/loader:1091:32)
    at Module._load (node:internal/modules/cjs/loader:938:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:83:12)
Emitted 'error' event on Server instance at:
    at emitErrorNT (node:net:1899:8)
    at process.processTicksAndRejections (node:internal/process/task_queues:82:21) {
  code: 'EACCES',
  errno: -4092,
  syscall: 'listen',
  address: '4000;',
  port: -1
}

Node.js v20.9.0
[nodemon] app crashed - waiting for file changes before starting...`

我按照教程操作了，但没有成功？尝试更改端口并杀死所有节点进程

Answer 1

删除

;

文件中的

.env