var filters = {
  /**
 * 参数1: 要截取的字符串
 * 参数2: 开始截取的index
 * 参数3: 结束截取的index
 */
  substring:function(val,start,end){
 
        if (val.length == 0 || val == undefined) {
              return;
        }

        return val.substring(start,end);
   }
}

module.exports = {
  substring:filters.substring
}