php判断字符串是否全英文,纯中文，中英文组合的方法

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                *function：检测字符串是否由纯英文，纯中文，中英文混合组成<br />*param string<br />*return 1:纯英文;2:纯中文;3:中英文混合<br />*/<br />function check_str($str=''){<br />	if(trim($str)==''){<br />		return '';<br />	}<br />	$m=mb_strlen($str,'utf-8');<br />	$s=strlen($str);<br />	if($s==$m){<br />		return 1;<br />	}<br />	if($s%$m==0&&$s%3==0){<br />		return 2;<br />	}<br />	return 3;<br /><p>}</p>

strtolower(urlencode($str));