Swift - How to I define a special method for my class that returns a string representation of its object

Question

In python if you want to define a string representation of an object you can do the following:

class Person:

    def __init__(self, first, last, age):
        self.first = first
        self.last = last
        self.age = age

    def __str__(self):
        return f'{self.first} {self.last}, {self.age} years old'

person_1 = Person('John', 'Smith', 25)

Now, if you write print(person_1) or str(person_1) , then you get John Smith, 25 years old .

If the __str__ method didn't exist, then the output would be <__main__.Person object at 0x104e12e20>

How do I do the same thing in swift?

sure, I could define a method with whatever name I want and then call it on the object, but it would lack syntactic sugar.

Answer 1

Just conform to the CustomStringConvertible protocol. All you have to do is implement the description property.

struct Person: CustomStringConvertible {
    let name: String
    let age: Int

    var description: String {
        return "[name: \(name), age: \(age)]"
    }
}

print(Person(name: "bob", age: 32)) // [name: bob, age: 32]