Swift equivalent for MIN and MAX macros
min
and max
are defined in Swift:
func max<T : Comparable>(x: T, y: T, rest: T...) -> T
func min<T : Comparable>(x: T, y: T, rest: T...) -> T
and used like so:
let min = min(1, 2)
let max = max(1, 2)
See this great writeup on documented & undocumented built-in functions in Swift.
As pointed out, Swift provides max
and min
functions.
An example (updated for Swift 2.x).
let numbers = [ 1, 42, 5, 21 ]
var maxNumber = Int()
for number in numbers {
maxNumber = max(maxNumber, number as Int)
}
print("the max number is \(maxNumber)") // will be 42
With Swift 5, max(_:_:)
and min(_:_:)
are part of the Global Numeric Functions. max(_:_:)
has the following declaration:
func max<T>(_ x: T, _ y: T) -> T where T : Comparable
You can use it like this with Int
s:
let maxInt = max(5, 12) // returns 12
Also note that there are other functions called max(_:_:_:_:)
and min(_:_:_:_:)
that allows you to compare even more parameters. max(_:_:_:_:)
has the following declaration:
func max<T>(_ x: T, _ y: T, _ z: T, _ rest: T...) -> T where T : Comparable
You can use it like this with Float
s:
let maxInt = max(12.0, 18.5, 21, 26, 32.9, 19.1) // returns 32.9
With Swift however, you're not limited to use max(_:_:)
and its siblings with numbers. In fact, those functions are generic and can accept any parameter type that conforms to Comparable
protocol, may it be String
, Character
or one of your custom class
or struct
.
Thereby, the following Playground sample code works perfectly:
class Route: Comparable, CustomStringConvertible {
let distance: Int
var description: String {
return "Route with distance: \(distance)"
}
init(distance: Int) {
self.distance = distance
}
static func ==(lhs: Route, rhs: Route) -> Bool {
return lhs.distance == rhs.distance
}
static func <(lhs: Route, rhs: Route) -> Bool {
return lhs.distance < rhs.distance
}
}
let route1 = Route(distance: 4)
let route2 = Route(distance: 8)
let maxRoute = max(route1, route2)
print(maxRoute) // prints "Route with distance: 8"
Furthermore, if you want to get the min/max element of elements that are inside an Array
, a Set
, a Dictionary
or any other sequence of Comparable
elements, you can use the max() or the min() methods (see this Stack Overflow answer for more details).