How do you start an Express server and listen on a specific port?app.run(port)app.listen(port)app.start(port)app.init(port)

To start an Express server and listen on a specific port, you would typically follow these steps:

1. First, you need to install Express. You can do this using npm (Node Package Manager) with the following command in your terminal:

npm install express

2. Once Express is installed, you can create a new file (for example, app.js) and require Express at the top of this file:

const express = require('express');

3. Next, you need to create an instance of an Express application. You can do this with the following line of code:

const app = express();

4. Now, you can tell your Express application to listen on a specific port. For example, if you wanted your application to listen on port 3000, you would use the following code:

app.listen(3000, function () {
  console.log('Example app listening on port 3000!');
});

5. Finally, you can start your server by running the following command in your terminal:

node app.js

This will start your Express server and it will listen on port 3000. You can replace 3000 with any port number you prefer.