text: import isArray from '../type/isArray';
  import isString from '../type/isString';
  import isObject from '../type/isObject';
  
  export default function keys(e){
    let res = [];
  
    if(e != null){
      if(isArray(e) || isString(e)){
        for(let i=e.length; i--; )
          res.unshift(i);
      }else if(isObject(e)){
        res = Object.keys(e);
      }
    }
  
    return res;
  }
  