how to read file extension in a folder in node js

How to Read File Extensions in a Folder in Node.js

To read file extensions in a folder in Node.js, you can use the fs (file system) module to interact with the file system and the path module to extract the file extension from the file name. Here are the steps to accomplish this:

1. Import the required modules:
2. Use the require function to import the fs module and assign it to a variable, such as fs.

3. Use the require function to import the path module and assign it to a variable, such as path.

4. Read the contents of the folder:

5. Use the fs.readdir function to read the contents of the folder.
6. Pass the folder path as the first argument to readdir.
7. Provide a callback function as the second argument to handle the result.
8. In the callback function, check for any errors. If an error occurs, handle it appropriately.

9. If there are no errors, the result will be an array of file names.

10. Extract the file extension from each file name:

11. Use the path.extname function to extract the file extension from each file name.
12. Pass each file name as an argument to extname.

13. Store the file extensions in an array or process them as needed.

14. Handle the file extensions:

15. You can perform various operations with the file extensions, such as filtering specific extensions, counting the occurrences of each extension, or performing any other desired logic.

Here's an example code snippet that demonstrates these steps:

const fs = require('fs');
const path = require('path');

const folderPath = '/path/to/folder';

fs.readdir(folderPath, (err, files) => {
  if (err) {
    console.error('Error reading folder:', err);
    return;
  }

  const fileExtensions = files.map((file) => path.extname(file));

  console.log('File extensions:', fileExtensions);
});

In this example, replace /path/to/folder with the actual path to the folder you want to read. The readdir function reads the contents of the folder, and the map function extracts the file extensions using extname. Finally, the file extensions are logged to the console.

Please note that this example assumes that the folder exists and that you have the necessary permissions to read its contents.