$regex = '[/u4e00-/u9fa5]'; //匹配中文字符的正則表達式$regex = '^[/u4E00-/u9FA5A-Za-z0-9]+$'; or $regex = '^[/u4E00-/u9FA5A-Za-z0-9]{2,20}$'; //中文、英文、數字但不包括下劃線等符號$regex = '^[a-zA-Z][a-zA-Z0-9_]{4,15}$'; //帳號是否合法(字母開頭，允許5-16字節，允許字母數字下劃線)$regex = '[^/x00-/xff]'; //匹配雙字節字符(包括漢字在內)$regex = '/n[/s| ]*/r'; //匹配空行的正則表達式$regex = '/<(.*)>.*<///1>|<(.*) //>/'; //匹配HTML標記的正則表達式$regex = '(^/s*)|(/s*$)'; //匹配首尾空格的正則表達式$regex = '/(/d+)/.(/d+)/.(/d+)/.(/d+)/g'; //匹配IP地址的正則表達式$regex = '/w+([-+.]/w+)*@/w+([-.]/w+)*/./w+([-.]/w+)*'; //匹配Email地址的正則表達式$regex = '^(13[0-9]|14[5|7]|15[0|1|2|3|5|6|7|8|9]|18[0|1|2|3|5|6|7|8|9])/d{8}$'; //手機號$regex = '^[1-9]/d{5}(18|19|([23]/d))/d{2}((0[1-9])|(10|11|12))(([0-2][1-9])|10|20|30|31)/d{3}[0-9Xx]$'; //18位身份證號$data = "***********";if (preg_match($regex,$data)) {  echo "驗證成功";} else {  echo "你輸入的是啥玩意？";}

$string = "abcd23uo*&* (.字符串過";preg_match_all("/[/w/s]/i", $string, $matches);print_r(implode('', $matches[0]));

$string = "abcd23uo*&* (.字符串過";preg_match_all("/([/x{4e00}-/x{9fa5}])/u", $string, $matches);print_r(implode('', $matches[0]));