Use Object.prototype.toString in JavaScript to determine whether an array

Why use Object.prototype.toString instead of Function.prototype.toString or something? This is related to the way their ToString is interpreted. The following is an explanation of the Object.prototype.toString in ECMA:

The code is as follows:

Object.prototype.toString ()

When the ToString method is called, the following steps are taken:

1. Get the [[Class]] property of this object.

2. Compute a string value by concatenating the three Strings "[object", result (1), and "]".

3. Return result (2)

The process is simply: 1, get the object's class name (object type). 2, and then the [object, get the class name,] combined and returned.

The array is described in ECMA as follows:

The code is as follows:

The [[Class]] property of the newly constructed object is set to "Array".

So we use the following code to detect the array:

The code is as follows:

function IsArray (o) {return Object.prototype.toString.call (o) = = ' [Object Array] ';}

This method not only solves the problem of instanceof, but also solves the problems existing in the method of attribute detection, which is a kind of coup and a good solution.

In addition, this solution can also be used to determine the types of objects such as date,function.

There are several other ways:

The code is as follows:

var arr = []; return arr instanceof Array;

If there are other good ways to post it.