/**
 * 判断数据类型模块
 * 为什么这样判断？这个说来话长...
 */ const toString = Object . prototype . toString ; param param export const isString = ( param ) : param is string => toString . call ( param ) === "[object String]" ; param param export const isArray = ( param ) : param is Array < any > => toString . call ( param ) === "[object Array]" ; param export const isObject = ( param ) : param is Object => toString . call ( param ) === "[object Object]" ;