Category: JavaScript

Sometimes, we want to get a list of the names of all files present in a directory in Node.js.

In this article, we’ll look at how to get a list of the names of all files present in a directory in Node.js.

How to get a list of the names of all files present in a directory in Node.js?

To get a list of the names of all files present in a directory in Node.js, we can call the readdir method.

For instance, we write

const testFolder = './folder/path';
const fs = require('fs');

fs.readdir(testFolder, (err, files) => {
  files.forEach(file => {
    console.log(file);
  });
});

to call fs.readdir with the testFolder folder path string and a callback that has all the files in an array.

In the callback, we call files.forEach to loop through each file entry.

Conclusion

To get a list of the names of all files present in a directory in Node.js, we can call the readdir method.

Sometimes, we want to get GET (query string) variables in Express.js on Node.js.

In this article, we’ll look at how to get GET (query string) variables in Express.js on Node.js.

How to get GET (query string) variables in Express.js on Node.js?

To get GET (query string) variables in Express.js on Node.js, we can get the from the req.query property.

For instance, we write

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

app.get('/', (req, res) => {
  res.send('id', req.query.id);
});

app.listen(3000);

to get the id query string parameter value with req.query.id.

Conclusion

To get GET (query string) variables in Express.js on Node.js, we can get the from the req.query property.

Sometimes, we want to check synchronously if a file or directory exists in Node.js.

In this article, we’ll look at how to check synchronously if a file or directory exists in Node.js.

How to check synchronously if a file or directory exists in Node.js?

To check synchronously if a file or directory exists in Node.js, we can use the existsSync method.

For instance, we write

const fs = require("fs"); 
if (fs.existsSync(path)) {
  // ...
}

to call fs.existsSync with a path string to check if the path points to a valid file or folder.

It returns true if it does and false otherwise.

Conclusion

To check synchronously if a file or directory exists in Node.js, we can use the existsSync method.

Sometimes, we want to read environment variables in Node.js.

In this article, we’ll look at how to read environment variables in Node.js.

How to read environment variables in Node.js?

To read environment variables in Node.js, we can read them from the process.env property.

For instance, we write

const mode = process.env.NODE_ENV;

to read the NODE_ENV environment variable and assign it to mode.

Conclusion

To read environment variables in Node.js, we can read them from the process.env property.

Sometimes, we want to debug Node.js applications.

In this article, we’ll look at how to debug Node.js applications.

How to debug Node.js applications?

To debug Node.js applications, we can use the node-inspector package.

We install it with

npm install -g node-inspector

Then we run

node-debug app.js

to start app.js with the node-inspector debugger.

Conclusion

To debug Node.js applications, we can use the node-inspector package.