Node.js path.extname() Method

The path.extname() method is used to get the extension portion of a file path. The extension string returned from the last occurrence of a period (.) in the path to the end of the path string. If there are no periods in the file path, then an empty string is returned.

Syntax:

path.extname( path )

Parameters: This method accepts single parameter path which holds the file path that would be used to extract the extension.

Return Value: It returns a string with the extension portion of the path. It throws a TypeError if this parameter is not a string value.

Below examples illustrate the path.extname() method in node.js:

Example 1:

// Node.js program to demonstrate the
// path.extname() method

// Import the path module
const path = require('path');

path1 = path.extname("hello.txt");
console.log(path1)

path2 = path.extname("readme.md");
console.log(path2)

// File with no extension
// Returns empty string
path3 = path.extname("fileDump")
console.log(path3)

// File with blank extension
// Return only the period
path4 = path.extname("example.")
console.log(path4)

path5 = path.extname("readme.md.txt")
console.log(path5)

// Extension name of the current script
path6 = path.extname(__filename)
console.log(path6)

Output:

.txt
.md

.
.txt
.js

Example 2:

// Node.js program to demonstrate the
// path.extname() method

// Import the path module
const path = require('path');

// Comparing extensions from a
// list of file paths
paths_array = [
    "/home/user/website/index.html",
    "/home/user/website/style.css",
    "/home/user/website/bootstrap.css",
    "/home/user/website/main.js",
    "/home/user/website/contact_us.html",
    "/home/user/website/services.html",
]

paths_array.forEach(filePath => {
    if (path.extname(filePath) == ".html")
        console.log(filePath);
});

Output:

/home/user/website/index.html
/home/user/website/contact_us.html
/home/user/website/services.html

Reference: https://nodejs.org/api/path.html#path_path_extname_path