Input
Output
<?php $greeting = " Hello World "; echo strlen($greeting); // Length: 13 echo trim($greeting); // "Hello World" echo strtoupper($greeting); // " HELLO WORLD " echo strtolower($greeting); // " hello world " echo str_replace("World", "PHP", $greeting); // " Hello PHP " echo substr($greeting, 1, 5); // "Hello" echo strpos($greeting, "World"); // Position: 7 ?>