3v4l.org

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<?php $myarr = array("world cup"); foreach($myarr as &$v){ if(strpos($v,'o')!==false) $myarr[] = str_replace('o','O',$v); if(strpos($v,'O')!==false) $myarr[] = str_replace('O','o',$v); } var_export($myarr);

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30.44 ms | 402 KiB | 5 Q