Swift Class Methods

Swift Class Methods

Use static or class to define type methods that belong to the type itself rather than an instance.

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Type Methods

Use class for overridable type methods; static methods cannot be overridden.

Example

class Math {
  class func square(_ n: Int) -> Int { n * n } // overridable in subclasses
  static func cube(_ n: Int) -> Int { n * n * n } // not overridable
}

print(Math.square(4))
print(Math.cube(3))

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Override class func

Use class for overridable type methods; static methods cannot be overridden.

Example

class Base {
  class func greet() { print("Base") }
  static func ping() { print("Base ping") }
}

class Sub: Base {
  override class func greet() { print("Sub") }
  // static func cannot be overridden
}

Base.greet()
Sub.greet()
Base.ping()