A query argument, also referred to as a URL parameter, is a data string appended to the end of a URL that dynamically customizes the information presented to the user.
Query arguments consist of a query string signified by a question mark (?) followed by one or more key-value pairs formatted as variable_name=value.
Multiple parameters are delimited by an ampersand (&).
For example, a query argument may look like ?category=shoes&brand=nike. This would filter a page to only show shoes made by Nike.
Examples of uses of query arguments:
- Specifying search terms: ?q=search+terms
- Filtering products by category: ?category=electronics
- Sorting search results: ?sort=price
- Paginating results: ?page=2
- Tracking referral source: ?ref=social_media
Query arguments can cause tracking problems in web analytics if not handled properly. Some issues include:
- Duplicate content: Multiple URLs with different query arguments may be seen as separate pages, even if they have the same content.
- Referral data loss: Query arguments used for tracking referrals may be stripped away by privacy-focused browsers, leading to inaccurate data.
- Skewed metrics: Unique query arguments for each user can inflate page view counts and other metrics.
To minimize tracking issues, web developers should use canonical URLs, configure analytics tools to ignore certain query arguments, and use server-side tracking methods when necessary.
In summary, query arguments dynamically pass information to the web server and database powering the site to influence what data gets embedded and displayed on the page for each unique URL request.
They allow customizable views without requiring entirely separate static pages.