函数作为返回值输出 判断数据类型

var gettype = function(type){
return function(obj){
return Object.prototype.toString.call(obj) == '[object '+ type +']';
}
}

var isString = gettype('String');
console.log(isString('123'));//true

var Type={};
for(var i=0,type;type=['String','Array','Number'][i++];){
(function(type){
Type['is' + type] = function(obj){
return Object.prototype.toString.call(obj) === '[object '+ type +']';
}
})(type);
}

console.log(Type.isArray( [] ));//true