Question: I was playing with below javascript code. Understanding of `Object.defineProperty()` and I am facing a strange issue with it. When I try to execute below code in the browser or in the VS code the output is not as expected whereas if I try to debug the code the output is correct

When I debug the code and evaluate the profile I can see the `name & age` property in the object
But at the time of output, it only shows the `name` property

```js
//Code Snippet 
let profile = {
  name: 'Barry Allen',
}

// I added a new property in the profile object.
Object.defineProperty(profile, 'age', {
  value: 23,
  writable: true
})

console.log(profile)
console.log(profile.age)
```

Now expected output here should be 

```
{name: "Barry Allen", age: 23}
23

```

but I get the output as.
Note that I am able to access the `age` property defined afterwards. 
I am not sure why the `console.log()` is behaving this way.

```
{name: "Barry Allen"}
23 

```

Answer: 
By default, properties you define with `defineProperty` are not *enumerable* - this means that they will not show up when you iterate over their `Object.keys` (which is what the snippet console does). (Similarly, the `length` property of an array does not get displayed, because it's non-enumerable.)

See [MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/defineProperty):

> 
> **enumerable**
> 
> 
> true if and only if this property shows up during enumeration of the properties on the corresponding object.
> 
> 
> **Defaults to false.**
> 
> 
> 

Make it enumerable instead:

```js
//Code Snippet 
let profile = {
  name: 'Barry Allen',
}

// I added a new property in the profile object.
Object.defineProperty(profile, 'age', {
  value: 23,
  writable: true,
  enumerable: true
})

console.log(profile)
console.log(profile.age)
```

The reason you can see the property in the [logged image](https://pasteboard.co/IaOxMqB.png) is that Chrome's console will show you non-enumerable properties as well - **but the non-enumerable properties will be slightly greyed-out**:

[![enter image description here](https://i.stack.imgur.com/1k4zA.png)](https://i.stack.imgur.com/1k4zA.png)

See how `age` is grey-ish, while `name` is not - this indicates that `name` is enumerable, and `age` is not.
Whenever you use".defineProperty" method of object. You should better define all the properties of the descriptor. Because if you don't define other property descriptor then it assumes default values for all of them which is false. So your console.log checks for all the enumerable : true properties and logs them.

```
//Code Snippet 
let profile = {
  name: 'Barry Allen',
}

// I added a new property in the profile object.
Object.defineProperty(profile, 'age', {
  value: 23,
  writable: true,
  enumerable : true,
  configurable : true
})

console.log(profile)
console.log(profile.age)

```