# . notation in Xcode

**URL:** <https://forums.kodeco.com/t/notation-in-xcode/33424>\
**Category:** macOS\
**Created:** [August 18, 2017, 4:53am UTC](https://forums.kodeco.com/t/notation-in-xcode/33424 "2017-08-18T04:53:20Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![edwin001](https://assets.chunter.kodeco.com/user_avatar/forums.kodeco.com/edwin001/32/102075_2.png) [@edwin001](https://forums.kodeco.com/u/edwin001)\
**Post date:** [August 18, 2017, 4:53am UTC](https://forums.kodeco.com/t/notation-in-xcode/33424/1 "2017-08-18T04:53:20Z")

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I dont understand why .white and .normal need a dot, what its means can someone explain ?

```
func updateUI() {
    if lightOn {
        view.backgroundColor = .white
        lightButton.setTitle("On", for: .normal)
    } else {
        view.backgroundColor = .black
        lightButton.setTitle("Off", for: .normal)
    }
}

```

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<div class="post-metadata">

**Author:** ![syedfa](https://assets.chunter.kodeco.com/user_avatar/forums.kodeco.com/syedfa/32/101500_2.png) [@syedfa](https://forums.kodeco.com/u/syedfa)\
**Post date:** [August 18, 2017, 3:30pm UTC](https://forums.kodeco.com/t/notation-in-xcode/33424/2 "2017-08-18T15:30:48Z")

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@edwin001 Thanks very much for your question! The .notation means that those values are actually enum values. When referencing an enum value, you would use the dot (.) value.

Here is an article that discusses ENUMS and other topics in more detail:

[Enums, Structs, and Classes in Swift](https://www.raywenderlich.com/119881/enums-structs-and-classes-in-swift)

I hope this helps 🙂

All the best!

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<div class="post-metadata">

**Author:** ![system](https://s3.amazonaws.com/cdn.raywenderlich.com/community/forum-assets/noun-game-ghost-878668.png) [@system](https://forums.kodeco.com/u/system)\
**Post date:** [January 31, 2018, 8:53pm UTC](https://forums.kodeco.com/t/notation-in-xcode/33424/3 "2018-01-31T20:53:21Z")

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