What’s the Difference Between filter_var_array and filter_input_array? Which One Fits Your Project Better?

[What’s the Difference Between filter_var_array and filter_input_array? Which One Fits Your Project Better?]

In PHP, data filtering is a crucial step to ensure application security and prevent malicious attacks. filter_var_array and filter_input_array are two commonly used functions. Both are designed to filter and validate input data, but they differ in certain details. This article compares the two functions to help developers understand their differences and choose the right one based on project needs.

1. Overview of filter_var_array

filter_var_array is the array version of filter_var, allowing developers to filter multiple variables at once. It accepts two parameters:

• The first parameter is an array containing the data to be filtered.

• The second parameter is an array that defines the filtering rules, which can be set using FILTER_* constants.

Example:

<span><span><span class="hljs-variable">$input_data</span></span><span> = [
    </span><span><span class="hljs-string">&#039;email&#039;</span></span><span> =&gt; </span><span><span class="hljs-string">&#039;[email protected]&#039;</span></span><span>,
    </span><span><span class="hljs-string">&#039;age&#039;</span></span><span> =&gt; </span><span><span class="hljs-string">&#039;25&#039;</span></span><span>
];
<p></span>$filters = [<br>
'email' => FILTER_VALIDATE_EMAIL,<br>
'age' => FILTER_VALIDATE_INT<br>
];</p>
<p>$filtered_data = filter_var_array($input_data, $filters);</p>
<p>print_r($filtered_data);<br>
</span>

In this example, email will be validated using FILTER_VALIDATE_EMAIL, while age will be checked to ensure it’s a valid integer. filter_var_array returns an array containing the filtered data.

2. Overview of filter_input_array

filter_input_array works similarly to filter_var_array, but it is primarily used to retrieve and filter data directly from PHP’s input streams. This function is commonly applied to handle data from $_GET, $_POST, $_COOKIE, or $_REQUEST. It also accepts two parameters:

• The first parameter is a constant specifying the source of input data (e.g., INPUT_GET, INPUT_POST, etc.).

• The second parameter is an array of filtering rules, similar to filter_var_array.

Example:

<span><span><span class="hljs-variable">$filters</span></span><span> = [
    </span><span><span class="hljs-string">&#039;email&#039;</span></span><span> =&gt; FILTER_VALIDATE_EMAIL,
    </span><span><span class="hljs-string">&#039;age&#039;</span></span><span> =&gt; FILTER_VALIDATE_INT
];
<p></span>$filtered_data = filter_input_array(INPUT_POST, $filters);</p>
<p>print_r($filtered_data);<br>
</span>

In this example, filter_input_array retrieves data from $_POST and applies the corresponding filtering rules.

3. Key Differences

Different Sources of Input Data

filter_var_array is used to filter any array of data. The source of input is entirely defined by the developer and could come from a database, file, session, or anywhere else.

filter_input_array is designed specifically to pull data from PHP’s built-in input streams (such as $_GET, $_POST, etc.). It is mainly used for processing form submissions, URL parameters, cookies, and other request data.

Different Parameter Passing

filter_var_array takes an array directly as input, whereas filter_input_array depends on PHP’s global input arrays like $_POST and $_GET.

Flexibility and Use Cases

filter_var_array works for any array that requires filtering, regardless of its source. In contrast, filter_input_array is more suitable for handling user-request data, especially form submissions or URL parameters.

4. Which One Fits Your Project Better?

• If you need to process external request data (such as form submissions, URL parameters, etc.) and validate it, filter_input_array is the better choice. It directly works with PHP’s input streams, making it convenient to use alongside global variables like $_GET and $_POST.

• If your data doesn’t come directly from PHP’s input streams but from other sources (like a database, file, or session), filter_var_array is more flexible and can filter any array as needed.

5. Conclusion

Both filter_var_array and filter_input_array are powerful tools. Their main difference lies in the source of input data and their intended use cases. Choosing the right one depends on your requirements:

• For processing form inputs, URL parameters, or cookies, use filter_input_array.

• For filtering data from other sources, use filter_var_array.

By selecting the right function based on your situation, you can effectively improve both the security and maintainability of your code.