2020-02-16 标签:别了,javascript,isxx,系列,实现,代码,如下,isnull,function,a,return,n,ull,isundefined,undefined,isnumber,typeof,umber,isstring,string

实现代码如下： isNull: function(a){ return a === null; }, isUndefined: function(a){ return a === undefined; }, isNumber: function(a){ return typeof a === 'nu

2020-02-16 标签:javascript,isxx,系列,是否,继续,使用,分析,实现,代码,如下,isnull,function,a,return,n,ull,isundefined,undefined,isnumber,typeof

实现代码如下： isNull: function(a){ return a === null; }, isUndefined: function(a){ return a === undefined; }, isNumber: function(a){ return typeof a === 'nu