Swift

9.4    Classes as Function Parameters

Just like structs, classes can also be used as function parameters. Listing 9.33 demonstrates an example, in which areNameSake accepts two Person instances (objects) to determine if they are namesakes.

class Person {    var name: String    init(name: String) { self.name = name }}func areNameSake(_ p1: Person, _ p2: Person) -> Bool {    return p1.name == p2.name}let student1 = Person(name: "Alice")let student2 = Person(name: "Bob")let student3 = Person(name: "Alice")print(areNameSake(student1, student2)) // falseprint(areNameSake(student1, student3)) // true  

Listing 9.33     Classes as Function Parameters

So far, so good: If Person was a struct, you could proceed with the same syntax. However, a logical difference ...