3v4l.org

run code in 300+ PHP versions simultaneously
<?php mb_substitute_character("long"); var_dump( $conv = mb_convert_encoding( $bin = hex2bin("70000000"), "UTF-8", "UCS-4BE" ), mb_check_encoding($bin, "UCS-4BE"), bin2hex(mb_convert_encoding($conv, "UCS-4BE", "UTF-8")) );
Output for 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
string(10) "U+70000000" bool(true) string(80) "000000550000002b0000003700000030000000300000003000000030000000300000003000000030"
Output for 7.4.0 - 7.4.33, 8.0.1 - 8.0.30
string(3) "?+0" bool(false) string(24) "0000003f0000002b00000030"
preferences:
60.69 ms | 1258 KiB | 4 Q