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run code in 300+ PHP versions simultaneously
<?php function msubstr($str, $start, $len) { $tmpstr = ""; $strlen = $start + $len; for($i = 0; $i < $strlen; $i++) { if(ord(substr($str, $i, 1)) > 0xa0) { $tmpstr .= substr($str, $i, 2); $i++; } else $tmpstr .= substr($str, $i, 1); } return $tmpstr; } var_dump(); // $a = '测试这是一个测试'; $a = 'xxxxbbbbbnnn'; $b = msubstr($a,0,5); var_dump($b); ?>

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27.25 ms | 402 KiB | 5 Q