Backend
API Design
Basics
URL, Query & Path Parameters

A URL (Uniform Resource Locator) is the address of a resource on the web. It identifies a specific location where the resource is available and tells the browser or client how to access it. A URL consists of different parts that together form a complete address.

Structure of a URL

A typical URL looks like this:

https://www.example.com:8080/path/to/resource?query=parameter#fragment

Let's break down this URL into its components:

  1. Scheme:

    • Specifies the protocol used to access the resource (e.g., http, https, ftp).
    • Example: https

  2. Host:

    • The domain name or IP address that identifies the server.
    • Example: www.example.com

  3. Port:

    • An optional part that specifies the port number on which the server is listening for requests.
    • Example: 8080

  4. Path:

    • Specifies the location of a specific resource on the server.
    • Example: /path/to/resource

  5. Query Parameters:

    • Additional parameters used to retrieve or filter the resource.
    • Example: ?query=parameter

  6. Fragment:

    • A reference to a specific section within the page.
    • Example: #fragment

Path Parameters

Path parameters are embedded directly in the URL path and are used to identify a specific resource. They typically specify the location or type of the resource.

  • Example:

    https://api.example.com/users/123

  • In this URL, 123 is a path parameter that identifies a specific user.

Query Parameters

Query parameters start after the ? at the end of the URL and are presented as key-value pairs. They provide additional data or context for the request. Multiple query parameters are separated by &.

  • Example:

    https://www.example.com/search?query=web&sort=asc

  • In this URL, query=web and sort=asc are query parameters that specify the search query and sorting order.

Usage of Path and Query Parameters

  • Path Parameters:

  • Uniquely identify specific resources or entities.

  • Example: /products/456 (Identifies the product with ID 456).

  • Query Parameters:

  • Used to specify filtering, sorting, and additional data.

  • Example: /products?category=books&sort=price (Filters products by category books and sorts by price).

Benefits of URL, Path, and Query Parameters

  • Clarity: URLs clearly represent resources and actions, making understanding and debugging easier.
  • Flexibility: Query parameters provide a flexible and powerful way to pass dynamic data without changing the resource path.
  • Modularity: Path parameters keep the URL structure modular and clean, improving readability and maintainability.

Conclusion

URL, path parameters, and query parameters are fundamental for web navigation and resource identification. Proper use of these components allows developers to set up clear and efficient communication between clients and servers. Understand URLs, use path and query parameters effectively, and create powerful and user-friendly web applications! 🌐🚀

Designing and Developing Robust APIsContent Negotiation