100分求个 检拆字符串长度

100分求个 检测字符串长度
$str[0] = "123asd你好[哈哈]"
$str[1] = "123asd你好[你好不好啊]"
//一个中文一个字符(utf-8的编码) 符号 [这里面的字和外边的符号算一个字符] 
然后计算长度
结果是$str[0]和$str[1]为长度9

最好写成一个函数。谢谢了


------解决方案--------------------
我没太看懂楼主的题，不过函数，手头上有一个。

PHP code

/**     * 得到utf8 的长度     * @author mu_rain     * @param String $str     * @return Int     */    static function strlen_utf8($str) {        $i = 0;        $count = 0;        $len = strlen ($str);        while ($i = $len) break;            if($chr & 0x80) {                $chr <font color="#e78608">------解决方案--------------------</font><br>

PHP code

    function myLen($str,$startTag='[',$endTag=']',$encoding='utf-8')    {        $st = preg_quote($startTag);        $et = preg_quote($endTag);        return mb_strlen(preg_replace("#{$st}[^{$et}]*{$et}#","~",$str),$encoding);    }echo myLen("123asd你好[哈哈]");//9<br><font color="#e78608">------解决方案--------------------</font><br>附赠字符串函数一堆　，慢用。<br>

PHP code

<?php /** * Created by JetBrains PhpStorm. * User: Administrator * Date: 12-2-17 * Time: 上午11:43 * To change this template use File | Settings | File Templates. *//** * 字符串处理基类. * @author mu_rain */class kString{    // ------------------------------------    /**     * replace  the base64_encode to encode the string     *     * @param  $str    对象的实例     * @package   KDG     * @subpackage    String     * @category    Putils     * @author        jim     *  @return mixed     */    // ------------------------------------    public static function encode($str){        $src  = array("/","+","=");        $dist = array("-a","-b","-c");        $old  = base64_encode($str);        $new  = str_replace($src,$dist,$old);        return $new;    }    // ------------------------------------    /**     * replace  the base64_decode to decode the string     *     * @param  $str    对象的实例     * @package        P     * @subpackage    String     * @category    Putils     * @author        jim     *  @return mixed     */    // ------------------------------------    public static function decode($str){        $src = array("-a","-b","-c");        $dist  = array("/","+","=");        $old  = str_replace($src,$dist,$str);        $new = base64_decode($old);        return $new;    }    // ------------------------------------    /**     * replace  the base64_decode to decode the string     *     * @param  $str    对象的实例     * @package        P     * @subpackage    String     * @category    Putils     * @author        jim     *  @return mixed     */    // ------------------------------------    public static function showAsFileSize($str){ // change 1024 to 1k        $count = intVal($str);        $destSize = $count/1024;        $destSize = round($destSize,1);        return $destSize."K";    }  }<div class="clear">