To remove the last 2, 3, 4, 5, or 7 characters of a string in PHP, you can use the substr function. Here’s an example code that demonstrates how to remove the desired number of characters from the end of a string:

$string = "Hello, World!";

// Remove the last 2 characters
$result = substr($string, 0, -2);
echo $result; // Output: Hello, Wor

// Remove the last 3 characters
$result = substr($string, 0, -3);
echo $result; // Output: Hello, Wo

// Remove the last 4 characters
$result = substr($string, 0, -4);
echo $result; // Output: Hello, W

// Remove the last 5 characters
$result = substr($string, 0, -5);
echo $result; // Output: Hello,

// Remove the last 7 characters
$result = substr($string, 0, -7);
echo $result; // Output: Hello

The substr function takes three parameters: the input string, the starting index (0 in this case), and the length of the substring. By using a negative length, you can specify the number of characters to exclude from the end of the string.