[Swift] Be aware of different behaviour between struct and class

	import Foundation
	class Cat: CustomStringConvertible {
	var description: String {
	return "\(name): \(age) years old"
	}
	let name: String
	var age: Int
	init(name: String = "Sue", age: Int = 0) {
	self.name = name
	self.age = age
	}
	}
	struct Dog: CustomStringConvertible {
	var description: String {
	return "\(name): \(age) years old"
	}
	let name: String
	var age: Int
	init(name: String = "Sue", age: Int = 0) {
	self.name = name
	self.age = age
	}
	}
	var cats = Array<Cat>(repeating: Cat(), count: 2)
	cats[1].age = 2
	var dogs = Array<Dog>(repeating: Dog(), count: 2)
	dogs[1].age = 2
	print("cats: \(cats)")
	print("dogs: \(dogs)")
	/*
	output:
	cats: [Sue: 2 years old, Sue: 2 years old]
	dogs: [Sue: 0 years old, Sue: 2 years old]
	*/

view raw RepeatingArrayElementsTest.swift hosted with ❤ by GitHub

References
- Swift - Classes and Structures#Classes Are Reference Types