What are common issues with escaping characters in PHP when constructing URLs?

One common issue with escaping characters in PHP when constructing URLs is that special characters, such as spaces or ampersands, can break the URL structure and lead to errors. To solve this problem, you can use the `urlencode()` function in PHP to properly encode special characters in the URL.

$url = "https://example.com/search?q=" . urlencode("special characters");
echo $url;