javascript, is there an isObject function like isArray? [duplicate]

Answer 1

use the following

It will return a true or false

theObject instanceof Object

Answer 2

In jQuery there is $.isPlainObject() method for that:

Description: Check to see if an object is a plain object (created using "{}" or "new Object").

Answer 3

You can use typeof operator.

if( (typeof A === "object" || typeof A === 'function') && (A !== null) )
{
    alert("A is object");
}

Note that because typeof new Number(1) === 'object' while typeof Number(1) === 'number'; the first syntax should be avoided.