Javascript Common Type Detection

1. Determine if the variable is the data type of the array?

Method One: Determine whether it has an "array nature", such as the slice () method. You can define the slice method for the variable yourself, so it sometimes fails.

Method Two: obj instanceof Array, but incorrect in some IE versions

Method Three: From the Zepto.js source code,

function IsArray (ARG) {     return Object.prototype.toString.call (arg) = = = "[Object Array]"    }

For browsers that support the new method Array.isarray () in the ECMA Script5, the following optimizations can be made.

if (typeof array.isarray=== "undefined") {  Array.isarray = function (arg) {        return Object.prototype.toString.call (arg) = = = "[Object Array]"    };  }

2. Determine if the variable is an object

function IsObject (ARG) {     return Object.prototype.toString.call (arg) = = = = "[Object Object]"    }

More in-depth judgment

function Isplainobject (obj) {return IsObject (obj)  && object.getprototypeof (obj) = = Object.prototype}

3. Determine if a variable is a function

function Isfunction (ARG) {     return Object.prototype.toString.call (arg) = = = = "[Object Function]"    }

　　

　　

　　

Javascript Common Type Detection