How to list the properties of a JavaScript object?

Question

Say I create an object thus:

var myObject =
        {\"ircEvent\": \"PRIVMSG\", \"method\": \"newURI\", \"regex\": \"^http://.*\"};

What is

Answer 1

Object.getOwnPropertyNames(obj)

This function also shows non-enumerable properties in addition to those shown by Object.keys(obj).

In JS, every property has a few properties, including a boolean enumerable.

In general, non-enumerable properties are more "internalish" and less often used, but it is insightful to look into them sometimes to see what is really going on.

Example:

var o = Object.create({base:0})
Object.defineProperty(o, 'yes', {enumerable: true})
Object.defineProperty(o, 'not', {enumerable: false})

console.log(Object.getOwnPropertyNames(o))
// [ 'yes', 'not' ]

console.log(Object.keys(o))
// [ 'yes' ]

for (var x in o)
    console.log(x)
// yes, base

Also note how:

• Object.getOwnPropertyNames and Object.keys don't go up the prototype chain to find base
• for in does

More about the prototype chain here: https://stackoverflow.com/a/23877420/895245