Swift Language Enums Basic enumerations
Example
An enum provides a set of related values:
enum Direction {
case up
case down
case left
case right
}
enum Direction { case up, down, left, right }
Enum values can be used by their fully-qualified name, but you can omit the type name when it can be inferred:
let dir = Direction.up
let dir: Direction = Direction.up
let dir: Direction = .up
// func move(dir: Direction)...
move(Direction.up)
move(.up)
obj.dir = Direction.up
obj.dir = .up
The most fundamental way of comparing/extracting enum values is with a switch statement:
switch dir {
case .up:
// handle the up case
case .down:
// handle the down case
case .left:
// handle the left case
case .right:
// handle the right case
}
Simple enums are automatically Hashable, Equatable and have string conversions:
if dir == .down { ... }
let dirs: Set<Direction> = [.right, .left]
print(Direction.up) // prints "up"
debugPrint(Direction.up) // prints "Direction.up"
