function asciSort(targ) {
    //字符串有方法charCodeAt，把字符转为ascii码
    var str = '',
        toAscFn = str.charCodeAt,
        _tempArr = targ ? targ.split('') : [],
        i = 0,
        j,
        _temp;
    if (_tempArr <= 1)
        return targ;
    for (; i < _tempArr.length; i++) { //冒泡算法
        for (j=0; j < _tempArr.length- i-1; j++) {
            //pre = _tempArr[j];
            //current = _tempArr[j + 1]
            if (toAscFn.apply(_tempArr[j]) < toAscFn.apply(_tempArr[j + 1])) {
                _temp = _tempArr[j];
                _tempArr[j] = _tempArr[j + 1];
                _tempArr[j + 1] = _temp;
            }
            //console.log(_tempArr);
        }
    }
    return _tempArr.join('');
};