How can you extract a specified number of characters from the end of a string in PHP?

To extract a specified number of characters from the end of a string in PHP, you can use the substr() function along with a negative start parameter. The negative start parameter indicates the position to start the extraction from the end of the string. By providing a negative start parameter and the desired number of characters to extract, you can easily retrieve the specified number of characters from the end of the string.

$string = "Hello, World!";
$characters = 6; // Number of characters to extract from the end
$extracted = substr($string, -$characters);
echo $extracted; // Output: World!