Node.js URL.format API

The URL.format API is used to format a URL object into a URL string. This API is a part of the built-in Node.js url module.

Syntax

The syntax for using the URL.format API is as follows:

url.format(urlObject[, options])

The urlObject parameter is a URL object that you want to format into a URL string. The options parameter is an optional set of formatting options that you can use to customize the output of the formatted URL string.

Examples

The following examples illustrate how to use the URL.format API:

const { URL } = require('url');

// format a URL string
const urlString = 'http://example.com/hello/world';
const urlObject = new URL(urlString);
const formattedUrl = url.format(urlObject);
console.log(formattedUrl);
// output: 'http://example.com/hello/world'

// format a URL string with custom options
const customOptions = { fragment: false };
const formattedUrlWithOptions = url.format(urlObject, customOptions);
console.log(formattedUrlWithOptions);
// output: 'http://example.com/hello/world'

// format a URL string and override its properties
const overrideUrlObject = { ...urlObject, protocol: 'https:', pathname: '/goodbye/world' };
const formattedOverrideUrl = url.format(overrideUrlObject);
console.log(formattedOverrideUrl);
// output: 'https://example.com/goodbye/world'

In the first example, we create a URL object from a URL string, and then format it back into a URL string using the URL.format API. The output is the original URL string.

In the second example, we create a custom options object with the fragment option set to false, and then format the URL object with this options object as a parameter. The output is the same URL string as the first example, but with the fragment component removed.

In the third example, we create a new object (overrideUrlObject) by spreading the properties of the original urlObject and then overriding its protocol and pathname properties. We then format the override URL object into a URL string, and the output is a new URL string with the overridden properties.

Conclusion

The URL.format API is a powerful tool for formatting URL strings and objects in Node.js. It allows developers to customize the output of a URL string with various options, and to override the properties of a URL object if necessary.