Use Methods in Swift

Written by Team Kodeco

Methods in Swift are functions that are associated with an instance of a class or structure. They can be used to perform actions or calculations on the properties of an object and can also take parameters and return values.

Here’s an example of how to define a method in a class:

class MyClass {
  var myProperty: Int
  
  init(propertyValue: Int) {
    self.myProperty = propertyValue
  }
  
  func doubleMyProperty() {
    myProperty *= 2
  }
}

This creates a new class called MyClass with a method called doubleMyProperty that doubles the value of the myProperty property.

You can call the method on an instance of the class like this:

let myObject = MyClass(propertyValue: 10)
myObject.doubleMyProperty()
print(myObject.myProperty) // prints "20"

Here’s an example of how to define a method that takes parameters and returns a value in a structure:

import Foundation
struct Point {
  var x: Double
  var y: Double
    
  init(x: Double, y: Double) {
    self.x = x
    self.y = y
  }
    
  func distance(to point: Point) -> Double {
    let deltaX = x - point.x
    let deltaY = y - point.y
    return sqrt(deltaX * deltaX + deltaY * deltaY)
  }
}

This creates a new structure called Point with a method called distance that takes one parameter of Point type and returns the distance between two points.

You can call the method on an instance of the structure like this:

let point1 = Point(x: 0.0, y: 0.0)
let point2 = Point(x: 3.0, y: 4.0)
let distance = point1.distance(to: point2)
print(distance) // prints "5.0