Swift 数组和包含，如何确定集合是否包含对象或值

如何使用 Swift 数组和集合来确定集合是否包含对象或值？

swift
let numbers = [1, 2, 3, 4, 5]
let containsThree = numbers.contains(3)
if containsThree {
    print("数组包含数字 3")
} else {
    print("数组不包含数字 3")
}

swift
let fruits: Set = ["apple", "banana", "orange"]
let containsApple = fruits.contains("apple")
if containsApple {
    print("集合包含苹果")
} else {
    print("集合不包含苹果")
}

swift
let emptyArray: [Int] = []
let nonEmptyArray: [Int] = [1, 2, 3]
if emptyArray.isEmpty {
    print("空数组")
} else {
    print("非空数组")
}
if nonEmptyArray.isEmpty {
    print("空数组")
} else {
    print("非空数组")
}