Have you ever wanted to understand how URLs work in JavaScript? If so, then you’ve come to the right place! In this article, we’ll be diving deep into the topic of URL parsing in JavaScript and understanding how to access certain data from a URL . string We’ll do so by breaking down the components of a URL into their individual parts — such as hostname, pathname, query, and hash — and taking each one for a spin. We’ll also be covering a few important tips and best practices when working with URL strings in JavaScript — so make sure you stick around until the end! Ultimately, this article is your one-stop shop for all things related to parsing URLs using JavaScript. So sit back and get ready to master the fundamentals of working with URLs in JavaScript! What Is URL Parsing and Why Should You Care? When you’re building a web application, understanding URL parsing is an essential skill. It’s the process of breaking down a address into its parts to interact with it more easily. web page By understanding URL parsing, you can take full advantage of your website’s ability to navigate through pages and information quickly and easily. URL parsing is not only helpful for navigation; it also provides an easier way to modify websites and access data. With URL parsing, you can pass variables and parameters to different pages using the query string, creating dynamic experiences for users by changing what appears on the page without refreshing the entire page. You can also access databases using the pathname portion of the URL, so that your web application can retrieve data from them without having to include them in a form or similar input field. Finally, you can use anchors (pieces beginning with ) to make navigating on a website smoother. # An Overview of the JavaScript URL Parsing Methods Breaking down a URL into its component pieces is an essential part of web development. By understanding the structure of a URL, you can easily interact with your backend services and retrieve data from remote sources. With JavaScript, there are several methods you can use to parse URLs and get more information from them. These include , , , and . URL URLSearchParams URLSearchParamsAPI location window.location Each method has its own benefits and drawbacks — let’s take a look at each one. : The native object allows you to create URLs, manipulate them, query their parts or set new values for their components. It also provides some useful features like encoding/decoding strings that contain sensitive information such as passwords or other personal data. URL URL : This method creates an object of key-value pairs that correspond to the query parameters of a URL. You can use it to create different parameters and set their values as needed. URLSearchParams : This API provides access to the core functionality of the object, allowing you to manipulate URLs in powerful ways like being able to iterate over all the elements in a URL without having to manually parse them yourself. URLSearchParamsAPI URLSearchParams : The property returns an object representing the current location—including hostname, pathname, search and hash components—which allows you to create links from within your application without having to manually construct URLs each time you need one. location : Similar to , this property also returns an object window.location location Understanding Hostname in JavaScript URL Parsing Hostname is the domain name that you use to visit a webpage or a website. It usually looks like this: . You can also use IP addresses in some cases, like www.example.com https://216.58.208.46 . You can get the hostname of the current page you’re visiting through the API method in JavaScript: location.hostname let hostname = window.location.hostname; This API method returns a string with the domain name (hostname) of the current page you’re visiting (for example, www.example.com ). The Hostname API method also has two other useful methods that you can use to return more specific information about the domain name, like the protocols used (i.e http or https). These are and . location.protocol location.port For example, if your hostname is , and you're using HTTPS to access it, then this code will return it as such: www.example.com let protocol = window.location.protocol; // returns "https:" let port = window.location.port; //returns "" (empty string) But if you’re using instead of HTTPS, then these two methods will return this instead: HTTP let protocol = window .location .protocol; // returns "http:" let port = window .location .port; //returns "80" (default HTTP port number) Understanding pathname in JavaScript URL Parsing Now we understand what hostname and query strings are, let’s look into the fourth and final part of URL parsing: the pathname in JavaScript. The pathname describes the location of a file or a resource on the web server. It starts with a forward slash and then followed by its directory name. Let's say you want to access , which is in the folder, which consists of films, music, literature, etc. The pathname will look something like this: . / index.html blog /blog/films/index.html For example, if you style your HTML page with a CSS, the pathname will let you know where your CSS file is located — in our example it would be something like . /blog/films/css/style.css Let’s see how to get the pathname using JavaScript! All you need to do is use this code snippet below: let url = new URL('https://example.com/blog/films'); let getpathname = url.pathname; // '/blog/films' You can try it out for yourself here. By default, if you don’t specify a specific file for your users, then will be used as the default document in most web servers as mentioned before. index.html Understanding how query strings and Hashes Work in JavaScript URL Parsing Now that you have a better understanding of hostnames, pathname and parameters, let’s take a look at the next parts of the URL: a query string and the hash. Query Strings and Hashes are used to specify additional parts of a url. Query strings are very useful for passing contextual information about the page to the server. The Hash is used to specify a certain part of the page to be displayed immediately after loading. In order to understand what exactly are query strings and hashes, let’s take a look at this example: http://example.com/search?q=javascript#hashtag . In this example, represents the search query that we are passing to our server and represents an anchor in which we can make our page jump directly to that part of the page after loading. q=javascript #hashtag Query strings and hashes can be accessed using object in JavaScript. window.location To access the query string of our example URL we need to call which will return us . window.location.search ?q=javascript To access only the value we need to use the syntax which will give us . window.location.search.split('=')[1] javascript Similarly, for hashes, we can use which will return us just . window.location.hash #hashtag Working With URLs Using ES6 Destructuring Syntax The next step in understanding how to parse a URL in JavaScript is to learn how to use ES6’s destructuring syntax. This is a bit more advanced than the previous methods we’ve covered, but it’s also the most convenient. Using ES6’s , you can break apart parts of a URL into separate variables. destructuring syntax To do this, all you need to do is wrap the URL in curly braces and use an sign to assign the variables: . = const { protocol, hostname, port } = new URL(url) This will assign each part of the URL string (protocol, hostname and port) to its own that you can use freely throughout your code. variable This method is particularly useful for assigning properties within an or for supplying arguments to a function. object Example: const { protocol, hostname, port } = new URL(url); const user = { protocol: protocol, domain: hostname, port: port }; Now let’s look at some examples. Example 1: Parsing Hostname from a URL To parse a hostname, use the property of an instance of . This will return the hostname portion of a given URL: hostname URLSearchParams let href = "https://www.example.com:8080/search#fragment?q=hello"; let url = new URLSearchParams(href); console.log(url.hostname); // Output: www.example.com In the above example, we log out the hostname in our console and get an output of www.example.com . So this is how we easily find out what is the hostname part of a given URL using JavaScript! Example 2: Parsing Pathname from a URL We can also parse out the pathname from an given URL using JavaScript like this: let href = "https://www.example.com/path/to/file"; let url = new URLSearchParams(href); console.log(url.pathname); // Output: /path/to/file In our code example, we create an instance of , and then use its property to get access to just the path segment from that particular URL; which in this case is `/path URLSearchParams pathName Conclusion All in all, URL parsing is an important part of web development, and JavaScript provides a powerful set of options to parse URLs with ease. The hostname, pathname, query, and hash properties allow you to break down URLs into their component parts, making it easier to build web applications and manipulate content. By following the steps outlined in this guide, you’ll be able to parse URLs quickly and easily, getting you one step closer to your goals. Also published . here
