Скачать или смотреть A Shorter Way to Sanitize Variables in PHP: filter_var and Null Coalescing Operator

Discover a concise method to sanitize request variables in PHP while avoiding undefined index notices.
---
This video is based on the question https://stackoverflow.com/q/65701734/ asked by the user 'Alexander Dobernig' ( https://stackoverflow.com/u/10805962/ ) and on the answer https://stackoverflow.com/a/65701864/ provided by the user 'El_Vanja' ( https://stackoverflow.com/u/4205384/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Shorter form of $var= isset($_REQUEST[ 'var' ]) ? filter_var

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
A Shorter Way to Sanitize Variables in PHP

When working with user input in PHP, particularly when receiving data through $_REQUEST, it’s vital to ensure that the data is both safe and valid. This involves checking if the variable exists and filtering it accordingly. However, this can sometimes lead to lengthy code that sacrifices readability for safety. If you've ever found yourself writing out an elaborate line like the one below, you’re not alone:

[[See Video to Reveal this Text or Code Snippet]]

In this post, we will not only examine a cleaner approach to this problem but also ensure that you retain the necessary filtering process while improving code brevity and readability.

The Problem: Verbose Conditionals

The initial code snippet does the following:

Checks if the variable exists: It uses isset() to see if $_REQUEST['var'] is set to avoid undefined index notices.

Sanitizes the input: If the variable exists, it applies filter_var() to sanitize it as an integer.

Defaults to 0: If the variable is not set, it defaults to 0 to prevent any further errors which could disrupt the application.

Common Issues Faced

Undefined Index Error: If you do not check if a variable exists, PHP raises a notice regarding an undefined index, which can clutter logs and confuse users.

Lengthy Syntax: The syntax not only becomes verbose but also difficult to read or maintain as application complexity increases.

The Solution: Using the Null Coalescing Operator

Fortunately, there is a cleaner way to achieve the same outcome using the null coalescing operator (??). The revised code simplifies the process considerably:

[[See Video to Reveal this Text or Code Snippet]]

How This Works:

Null Coalescing Operator: $_REQUEST['var'] ?? 0 will return the value of $_REQUEST['var'] if it exists; if not, it will return 0. This prevents the undefined index notice, as the operator ensures a fallback value.

Applying Filter Directly: The filter_var() function is applied directly to the coalesced value. Therefore, whatever value is retrieved (either the sanitized input or the default value of 0) is safely processed.

Benefits of This Approach:

Conciseness: The line of code is significantly shorter, making it easier to read and understand at a glance.

Maintenance: With less clutter, maintaining and updating your code becomes simpler.

Safety: You still maintain the essential checks and sanitization, ensuring safety and security against invalid data.

Final Thoughts

In PHP, it's crucial to handle request variables carefully, but it doesn't have to be complicated. By utilizing the null coalescing operator alongside filter_var(), you can maintain both clarity and functionality in your code.

Now, the next time you're handling user input, remember that a shorter, neater approach is not only possible but also advisable for cleaner code management.