Identifiers in Node.js

Identifiers in Node.js are names used to refer to various entities, including variables, functions, classes, and modules. They help in accessing and manipulating data and functionality within application. Identifiers are essential for creating and managing different aspects of your codebase efficiently.

1. Variables: Names for storing data

const port = 3000; // Identifier: `port`
let server = require('http').createServer(); // Identifier: `server`

2. Functions: Names for functions

function startServer() {} // Identifier: `startServer`

3. Classes: Names for classes used to create objects with specific properties and methods

class User {
  constructor(name) {
    this.name = name;
  }
} // Identifier: `User`

4. Modules: Names for files or modules that are imported or required

const fs = require('fs'); // Identifier: `fs`
const express = require('express'); // Identifier: `express`

5. Objects: Keys in objects act as identifiers for their corresponding values

const config = {
  host: 'localhost', // Identifier: `host`
  port: 3000 // Identifier: `port`
};

6. Labels: Names used to label loops and control flow

outerLoop: for (let i = 0; i < 5; i++) { // Identifier: `outerLoop`
  for (let j = 0; j < 5; j++) {
    if (j === 3) {
      break outerLoop; // Identifier: `outerLoop`
    }
  }
}