How to tell if a variable is an array, function, or object type in JavaScript

Array

ECMAScript5 Array.isarray is the native method of judging arrays, IE9 and above support. For compatibility, in browsers that do not have this method, you can use Object.prototype.toString.call (obj) = = = ' [Object Array] ' instead.

var IsArray = Array.isarray | | function (obj) {return Object.prototype.toString.call (obj) = = = ' [Object Array] ';}

Function

The simplest and best-performing approach is to typeof obj = = ' function '. The most reliable way to consider the bugs of some version browsers is Object.prototype.toString.call (obj) = = = ' [Object Function] '.

var isfunction = function (obj) {return Object.prototype.toString.call (obj) = = = ' [Object function] ';} if (typeof/./! = ' function ' && typeof int8array! = ' object ') {isfunction = function (obj) {return typeo    F obj = = ' function '; }}

Object

In JavaScript, a complex type is an object, and a function is an object. For the above 2 use typeof, you can get ' object ' and ' function ' separately. Also, the case of null values is excluded, because typeof null gets the ' object ' as well.

var isobject = function (obj) {var type = typeof obj; return type = = = ' function ' | | Type = = = ' object ' &&!! obj;}

How to tell if a variable is an array, function, or object type in JavaScript