中英數字混合的字符串截取

/**
     * 中英數字混合的字符串截取
     * Param: 參數說明
     * 【in】$sourcestr string  截取字符串
     * 【in】$cutlength int  截取長度
     */
    public function assoc_substr($sourcestr, $cutlength) {
        $returnstr = '';
        $i = 0;
        $n = 0;
        $str_length = strlen ( $sourcestr ); //字符串的字節數
        while ( ($n < $cutlength) and ($i <= $str_length) ) {
            $temp_str = substr ( $sourcestr, $i, 1 );
            $ascnum = Ord ( $temp_str ); //獲得字符串中第$i位字符的ascii碼
            if ($ascnum >= 224) {//若是ASCII位高與224,
                $returnstr = $returnstr . substr ( $sourcestr, $i, 3 ); //根據UTF-8編碼規範,將3個連續的字符計爲單個字符
                $i = $i + 3; //實際Byte計爲3
                $n ++; //字串長度計1
            } elseif ($ascnum >= 192){ //若是ASCII位高與192,
                $returnstr = $returnstr . substr ( $sourcestr, $i, 2 ); //根據UTF-8編碼規範,將2個連續的字符計爲單個字符
                $i = $i + 2; //實際Byte計爲2
                $n ++; //字串長度計1
            } elseif ($ascnum >= 65 && $ascnum <= 90) {//若是是大寫字母,
                $returnstr = $returnstr . substr ( $sourcestr, $i, 1 );
                $i = $i + 1; //實際的Byte數仍計1個
                $n ++; //但考慮總體美觀,大寫字母計成一個高位字符
            }elseif ($ascnum >= 97 && $ascnum <= 122) {
                $returnstr = $returnstr . substr ( $sourcestr, $i, 1 );
                $i = $i + 1; //實際的Byte數仍計1個
                $n ++; //但考慮總體美觀,大寫字母計成一個高位字符
            }elseif($ascnum>=48 && $ascnum<=57){
                $returnstr = $returnstr . substr ( $sourcestr, $i, 1 );
                $n ++; //但考慮總體美觀,大寫字母計成一個高位字符
            }else {//其餘狀況下,半角標點符號,
                $returnstr = $returnstr . substr ( $sourcestr, $i, 1 );
                $i = $i + 1;
                $n = $n + 0.5;
            }
        }
        return $returnstr;
    }
相關文章
相關標籤/搜索