Welcome to the Treehouse Community
Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.
Looking to learn something new?
Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.
Start your free trial
Derrick Hoff
9,385 Pointswhats wrong with my override function move
the error message I keep getting when I look at the preview is :
swift_lint.swift:33:19: error: argument names for method 'move(direction:)' do not match those of overridden method 'move' override func move(direction: String) {
with an arrow pointing at the "m" what am I doing wrong I tried Capitalizing it but that didn't work either?
class Point {
var x: Int
var y: Int
init(x: Int, y: Int) {
self.x = x
self.y = y
}
}
class Machine {
var location: Point
init() {
self.location = Point(x: 0, y: 0)
}
func move(_ direction: String) {
print("Do nothing! I'm a machine!")
}
}
// Enter your code below
class Robot: Machine {
override func move(direction: String) {
switch direction {
case "Up": self.location.y += 1
case "Down": self.location.y -= 1
case "Left": self.location.x -= 1
case "Right": self.location.x += 1
default: break
}
}
}
1 Answer
andren
28,558 PointsWhen you override a method the declaration has to be 100% identical. The original move method has an external parameter name of _. In your method you do not specify an external parameter name.
If you fix that by specifying _ as the external parameter name in your own move method like this:
class Point {
var x: Int
var y: Int
init(x: Int, y: Int) {
self.x = x
self.y = y
}
}
class Machine {
var location: Point
init() {
self.location = Point(x: 0, y: 0)
}
func move(_ direction: String) {
print("Do nothing! I'm a machine!")
}
}
// Enter your code below
class Robot: Machine {
override func move(_ direction: String) { // <- Added _ as external parameter name
switch direction {
case "Up": self.location.y += 1
case "Down": self.location.y -= 1
case "Left": self.location.x -= 1
case "Right": self.location.x += 1
default: break
}
}
}
Then your code will work.