tryphp_keyword_callable2.php:
<!DOCTYPE html> <html> <body> <?php function printFormatted(callable $format, $str) { echo $format($str); echo "<br>"; } class MyClass { public static function ask($str) { return $str . "?"; } public function brackets($str) { return "[$str]"; } } // An anonymous function $func = function($str) { return substr($str, 0, 5); }; printFormatted($func , "Hello World"); // A string containing the name of a function printFormatted("strtoupper", "Hello World"); // An array describing a static class method printFormatted(["MyClass", "ask"], "Hello World"); // An array describing an object method $obj = new MyClass(); printFormatted([$obj, "brackets"], "Hello World"); ?> </body> </html>
Hello
HELLO WORLD
Hello World?
[Hello World]