$str = "hello world"; echo strtoupper($str); // output: HELLO WORLD
$str = "HELLO WORLD"; echo strtolower($str); // output: hello world
$str = "this is a sentence"; echo ucfirst($str); // output: This is a sentence
$str = "this is a sentence"; echo ucwords($str); // output: This Is A Sentence
$str = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed sed lectus risus."; echo wordwrap($str, 20, "These examples are all using built-in functions from the core PHP library.
"); // output: Lorem ipsum dolor
sit amet,
consectetur adipiscing
elit. Sed sed lectus
risus.