express.js 应用程序未显示控制台日志消息

Question

const express = require("express");
const app = express();

app.listen(3000, function () {
  console.log("started at 3000");
});

app.get("/", function (req, res) {

  console.log("Hello");

  const car = "read";

  res.send("Hello, world");

});

res.send is working fine. However, console log is not showing. It only shows when I remove the variable.

I am running using nodemon.

Any idea what's going on?

Answer 1

it works perfectly fine,just to confirm things add app.listen() to the bottom of code.

1. after running nodemon app.js

2. open browser-> visit localhost:3000 , you will see the hello in your console/cmd/terminal

Reason :- The below mentioned code literally means when a GET request is send to this path ie "/" then, in the console print "Hello", and as a response to that GET request, send "Hello,World"

const port =3000||port.env.PORT

app.get("/", function (req, res) {

  console.log("Hello");

  const car = "read";

  res.send("Hello, world");

});
    app.listen(port, function () {
  console.log("started at "+port);
});

Sometimes nodemon can be a little wacky or late to take in the updates,in such situations, therefore, try stopping the server and rerun it using the nodemon command

Answer 2

Your code is working fine. As good practice. Always put app.listen as the last code in index (entry) file.

const express = require("express");
const app = express();

app.get("/", function (req, res) {

    console.log("Hello");
  
    const car = "read";
  
    res.send("Hello, world");
  
  });

app.listen(3000, function () {
  console.log("started at 3000");
});

Answer 3

If you're using Postman to send your GET request, the console.log() should show up in the console in vscode or wherever you run your express server from, it will not display in Postman as part of the api response. For your console to log correctly you need to restart your server every time you change your files, so you say you use Nodemon for that. Maybe try stopping and restarting your project again manually? Are you looking for the console.log to display in the right place?

Answer 4

there is no problem in your code it's absolutely right

you can see the console.log("hello") in the cmd

when you run the localhost:3000 in your browser you can see it at cmd after 'started at 3000'

Answer 5

具有自动保存功能的 Nodemon 会导致问题，请改用手动保存 (Ctrl + S)