What does object Object mean JavaScript

Question

One of my alerts is giving the following result     object Object     What does this mean exactly   This was an alert of some jQuery object

User · Accepted Answer

It means you are alerting an instance of an object. When alerting the object, toString() is called on the object, and the default implementation returns [object Object].

var objA = {};
var objB = new Object;
var objC = {};

objC.toString = function () { return "objC" };

alert(objA); // [object Object]
alert(objB); // [object Object]
alert(objC); // objC

If you want to inspect the object, you should either console.log it, JSON.stringify() it, or enumerate over it's properties and inspect them individually using for in.

User · Answer

The alert   function can t output an object in a read-friendly manner  Try using console log object  instead  and fire up your browser s console to debug

User · Answer

Another option is to use JSON stringify obj   For example   exampleObj     a  1  b  2  c  3   alert JSON stringify exampleObj     https   www w3schools com js js json stringify asp

User · Answer

That is because there are different types of objects in Javascript  For example  Function objects   stringify function       - gt   object Function   Array objects   stringify     - gt   object Array   RegExp objects  stringify  x   - gt   object RegExp   Date objects  stringify new Date  - gt   object Date        Object objects   stringify     - gt   object Object  the constructor function is called Object  with a capital  quot O quot    and the term  quot object quot   with small  quot o quot   refers to the structural nature of the thingy  When you re talking about  quot objects quot  in Javascript  you actually mean  quot Object objects quot   and not the other types  If you want to see value inside  quot  Object objects  quot  use  console log JSON stringify result

User · Answer

Alerts aren t the best for displaying objects  Try console log  If you still see Object Object in the console  use JSON parse like this   var obj   JSON parse yourObject   console log obj

User · Answer

If you are popping it in the DOM then try wrapping it in    lt pre gt       lt code gt  JSON stringify REPLACE WITH OBJECT  null  4   lt  code gt   lt  pre gt    makes a little easier to visually parse

User · Answer

As  Matt answered the reason of  object object   I will expand on how to inspect the value of the object  There are three options on top of my mind     JSON stringify JSONobject   console log JSONobject   or iterate over the object    Basic example   var jsonObj       property1    one       property2    two       property3    three       property4    fourth       var strBuilder       for key in jsonObj      if  jsonObj hasOwnProperty key         strBuilder push  Key is     key      value is     jsonObj key      n           alert strBuilder join          or console log strBuilder join        https   jsfiddle net b1u6hfns

[javascript] What does [object Object] mean? (JavaScript)

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