- substr: documentation ( source)
- mb_substr: documentation ( source)
- print_r: documentation ( source)
<?php
print_r([
'substr without length' => substr('Hello World', 1),
'substr with null length' => substr('Hello World', 1, null),
'mb_substr without length' => mb_substr('Hello World', 1),
'mb_substr with null length' => mb_substr('Hello World', 1, null),
]);