- var_dump: documentation ( source)
- mb_detect_encoding: documentation ( source)
<?php
$str2 = "ayC0zXLnDP26WNV9FMObB0u7G4Wij+Ig0XRAQK/T4VI659bV9oIxBoEzwJVYIvhTSM6p7w==";
var_dump(mb_detect_encoding($str2, 'CP936'));
var_dump(mb_detect_encoding($str2, 'EUC-CN'));
var_dump(mb_detect_encoding($str2, 'UTF-8'));