---
title: "Swift and enums #1"
slug: swift-and-enums-1
section: tech
date: 2015-07-30T12:35:00.000Z
canonical: https://roland.leth.ro/blog/tech/swift-and-enums-1
---

This will only work for `enums` that are `Ints`, start from `0`, and increment by 1 - for example `tableView` / `collectionView` sections, but I think it's a nice little trick that I always use:

```swift
private enum Section: Int {
  case products
  case shippingDetails
  case paymentDetails
  case totalValue
  case numberOfSections
}
```

Now you can do the following:

```swift
func numberOfSections(in collectionView: UICollectionView) -> Int {
  return Section.numberOfSections.rawValue
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: NSIndexPath) -> UICollectionViewCell {
  let cell: UICollectionViewCell

  // Since numberOfSections returns Section.numberOfSections,
  // it's safe to force unwrap here; it will never crash.
  switch Section(rawValue: indexPath.section)! {
  case .products: // [...]
  case .shippingDetails: // [...]
  case .paymentDetails: // [...]
  case .totalValue: // [...]
  // Now comes the downside: either do a default case,
  // either add the .numberOfSections case, both of which
  // do nothing, but I think it's worth the minor inconvenience.
  case .numberOfSections // default:
  }
}
```

Then, in the future, if the requirements change, and you need the `paymentDetails` section to be second, you don't have to remember which index it was and make sure you change it accordingly in `didSelectItemAtIndexPath`, as well - just move it in front of `shippingDetails` inside the `enum` declaration. Or, if you need to add / remove a section, you don't need to remember to update `numberOfSections`, it will continue work by itself.