How can the substr function in PHP be utilized effectively?

The substr function in PHP can be utilized effectively to extract a portion of a string based on a specified starting position and length. This can be useful for manipulating strings, such as extracting a substring from a larger string or truncating text to a certain length.

// Example of using substr to extract a portion of a string
$string = "Hello, World!";
$substring = substr($string, 0, 5); // Extracts the first 5 characters
echo $substring; // Output: Hello