How to get the last n characters of a PHP string?

Write a PHP program to get last n characters of a given string. Examples:

Input : $str = "GeeksforGeeks!"
        $n = 6 
Output : Geeks!

Input : $str = "GeeksforGeeks!"
        $n = 9
Output : forGeeks!

Method 1: Tn this method, traverse the last N characters of the string and keep appending them in a new string. Example: php

<?php

$str = "GeeksforGeeks!";
$n = 6;

// Starting index of the string
// where the new string begins
$start = strlen($str) - $n;

// New string
$str1 = '';

for ($x = $start; $x < strlen($str); $x++) {
    
    // Appending characters to the new string
    $str1 .= $str[$x];
}

// Print new string
echo $str1;
?>

Method 2: Another way to do this use inbuilt library function substr with parameters as the name of the string. Example: php

<?php

$str = "GeeksforGeeks!";
$n = 6;

$start = strlen($str) - $n;

// substr returns the new string.
$str1 = substr($str, $start);

echo $str1;
?>

Note: In above example, $start can also take -N to create a sub-string of last n characters