Declare in Swift

In Swift, you can declare a class using the class keyword followed by the name of the class. Here's an example:

class Person {
    var name: String
    var age: Int
    
    init(name: String, age: Int) {
        self.name = name
        self.age = age
    }
    
    func sayHello() {
        print("Hello, my name is \(name) and I am \(age) years old.")
    }
}

In the code above, we have declared a Person class with two properties (name and age) and one method (sayHello()). The init() method initializes the name and age properties with the values passed in as parameters. The sayHello() method prints a string to the console that includes the name and age properties.

You can create an instance of the Person class like this:

let person = Person(name: "John", age: 30)
person.sayHello() // Output: "Hello, my name is John and I am 30 years old."