Why is my PHP code returning an empty result when trying to retrieve GET URL parameters using `$_GET['link']`?

Retrieving GET URL Parameters in PHP

Question:

When attempting to access a URL passed as a parameter via a URL form (e.g., http://localhost/dispatch.php?link=www.google.com), the code returns an empty result using $_GET['link'];. What is the issue?

Answer:

The $_GET array is a superglobal that stores GET parameters. However, it functions as a variable rather than a language construct. To access its values, use the echo statement:

echo $_GET['link'];

To handle cases where the parameter is not present, you can employ conditional statements:

if (isset($_GET['link'])) {
    echo $_GET['link'];
} else {
    // Fallback behavior here
}

Alternatively, you can use the filter extension for validation and error handling:

echo filter_input(INPUT_GET, 'link', FILTER_SANITIZE_URL);

Finally, the null coalescing operator (PHP 7.0 onwards) provides concise fallback behavior:

echo $_GET['link'] ?? 'Fallback value';

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