Are there best practices for handling and decoding base64 strings in PHP to prevent errors like "Invalid length for a Base-64 char array"?

When working with base64 strings in PHP, it's important to ensure that the string is properly padded with '=' characters at the end to make its length a multiple of 4. This padding is necessary for decoding the string correctly and preventing errors like "Invalid length for a Base-64 char array". To fix this issue, you can add padding to the base64 string before decoding it using the `str_pad()` function.

$base64String = "SGVsbG8gV29ybGQh"; // Example base64 string
$padding = strlen($base64String) % 4; // Calculate the padding needed
$base64String = str_pad($base64String, strlen($base64String) + $padding, '=', STR_PAD_RIGHT); // Add padding
$decodedString = base64_decode($base64String); // Decode the base64 string
echo $decodedString; // Output the decoded string