Failable initializers in Swift

Failable initializers in Swift:

Failable initializers in Swift is an initializer that can return nil to indicate that the initialization process has failed.
Failable initializers are declared using the init? keyword.
They are commonly used when the initialization of an object might not be successful due to certain conditions or invalid parameters.

Here’s a simple example of a failable initializer:

struct User {
  let name: String
  let age: Int

   init?(name: String, age: Int) {
    if age < 0 {
      return nil
   }
    self.name = name
    self.age = age
  }
}

let validUser = User(name: "Sid", age: 26)  // User(name: "Sid", age: 26)
let inValidUser = User(name: "Sim", age: -1) // nil

// Usage of the failable initializer
if let user = User(name: "Sid", age: 26) {
    print("User Details: \(user.name), \(user.age)")
} else {
    print("Invalid User")
}

Here Person struct is an example of a failable initializer. It’s designed to create a Person instance with a given name and age, but it returns nil if the provided age is less than 0. This is a reasonable use of a failable initializer to handle the case where the initialization may fail due to invalid input.