<html>
<body>
function my_callback($item) {
return strlen($item);
}
$strings = ["apple", "orange", "banana", "coconut"];
$lengths = array_map("my_callback", $strings);
print_r($lengths);
</body>
</html>
Array ( [0] => 5 [1] => 6 [2] => 6 [3] => 7 )