What are some best practices for effectively highlighting and manipulating strings within PHP code?

When manipulating strings within PHP code, it is important to use built-in functions effectively to achieve the desired outcome. Some best practices include using functions like `strlen()` to find the length of a string, `substr()` to extract a portion of a string, and `str_replace()` to replace occurrences of a substring within a string.

// Example of manipulating strings in PHP
$string = "Hello, World!";
$length = strlen($string);
$substring = substr($string, 0, 5);
$newString = str_replace("World", "PHP", $string);

echo "Length of string: " . $length . "\n";
echo "Substring: " . $substring . "\n";
echo "Modified string: " . $newString;