JavaScript: [object Object]

Question

var a = null;
var b = {};
var c = a || b;
console.log(c);
// output: {}
alert(c);
// output: [object Object]

If console.log(c) prints {}, why does alert(c) outputs [object Object]? What does it mean exactly?

Answer 1

Prof. Dr. Zoltán Vass I get the same output("[object Object]") in both console.log and alert.
This behavior is browser(engine) dependant. Looks like some engines use toString and others use JSON.stringify for console logs
https://code.sololearn.com/WQu5hRmsJ4qt/?ref=app

Answer 2

Prof. Dr. Zoltán Vass Yes..

Answer 3

Pluto I’m trying to decrypt the deeper self identity implications of this self representation :) beside the strong js preference, of course

Answer 4

c value takes the value of b because a is null.
console output prints {} because c is an empty object.

alert can output only text so it shows [object Object]

Answer 5

Here is an example:

https://code.sololearn.com/WBqxOBbJhV9v/?ref=app

Answer 6

Glad you found it helpful

Answer 7

Kevin Star Very interesting! Things are usually more complicated than they seem to be at first sight

Answer 8

It prints its string format
Try c.toString()
And you will see [object Object]

The first object means its an object.
The second Object means its of type Object

Answer 9

A fun fact: Burey has this line as his profile description. 😂

Answer 10

Gabriel Ilie Very nice and clear example