Swift 对象中的自定义相等性保留了与遗留 Objective-C 代码的兼容性

Swift 是一种现代化的编程语言，它与 Objective-C 具有很高的兼容性。在 Swift 中，我们可以通过实现自定义的相等性来判断两个对象是否相等。这种自定义相等性的保留，使得 Swift 代码可以与遗留的 Objective-C 代码无缝衔接。

swift
class Person: NSObject {
    var name: String
    var age: Int
    
    init(name: String, age: Int) {
        self.name = name
        self.age = age
    }
}

swift
extension Person {
    override func isEqual(_ object: Any?) -> Bool {
        guard let otherPerson = object as? Person else {
            return false
        }
        
        return self.name == otherPerson.name && self.age == otherPerson.age
    }
}

swift
let person1 = Person(name: "John", age: 30)
let person2 = Person(name: "John", age: 30)
if person1 == person2 {
    print("person1 and person2 are equal")
} else {
    print("person1 and person2 are not equal")
}

swift
struct Point: Equatable {
    var x: Int
    var y: Int
    
    static func ==(lhs: Point, rhs: Point) -> Bool {
        return lhs.x == rhs.x && lhs.y == rhs.y
    }
}