Overload the `+` Addition Operator for Custom Swift Types

Written by Team Kodeco

When working with custom types in Swift, you may want to overload the + operator to perform custom logic when adding two instances of that type together.

Here’s an example of how you might overload the + operator for a custom Point class:

class Point {
  var x: Int
  var y: Int

  init(x: Int, y: Int) {
    self.x = x
    self.y = y
  }
}

extension Point {
  static func +(lhs: Point, rhs: Point) -> Point {
    return Point(x: lhs.x + rhs.x, y: lhs.y + rhs.y)
  }
}

In this example, you define a Point class with x and y properties. You then define an extension on the Point class and overload the + operator by defining a static function called + that takes two Point parameters and returns a new Point instance with the x and y properties added together.

Now you can use the + operator to add two Point instances together:

let point1 = Point(x: 1, y: 2)
let point2 = Point(x: 3, y: 4)
let point3 = point1 + point2
print(point3.x) // 4
print(point3.y) // 6