How to modify instance value without using a function? - ios

Question

I have a class:
class WeaponItems {
var name: String
var index: Int
var price: Int
var weaponPower: Int = 0
var attackSpeed: Double = 0
var criticalChance: Double = 0
var criticalDamage: Double = 0
init(name: String, index: Int, price: Int){
self.name = name
self.index = index
self.price = price
}
var weaponBlade = WeaponItems(name: "Weapon Blade", index: 0, price: 300)
weaponBlade.weaponPower = 15
// Error: expected declaration
var swiftShooter = WeaponItems(name: "Swift Shooter", index: 1, price: 300)
swiftShooter.attackSpeed = 0.2
// Error: expected declaration
var minionsFoot = WeaponItems(name: "Minions Foot", index: 3, price: 300)
minionsFoot.criticalChance = 0.1
minionsFoot.criticalDamage = 0.1
// Error: expected declaration
}
I need to set weaponPower attackSpeed ... for each item, I got an error doing it this way.
I found answers saying you have to use a function to modify instances' values, but I feel that makes the code complicated, how do I set the value of it otherwise?
The concern of using a function is it'll separate the instance-creating and value-setting process, making the code harder to maintain.

Answer 1

you should add properties for all the weaponItems in the class
then your class implementation should look like this
class WeaponItems {
var name: String
var index: Int
var price: Int
var weaponPower: Int = 0
var attackSpeed: Double = 0
var criticalChance: Double = 0
var criticalDamage: Double = 0
var weaponBlade:WeaponItems{
get {
let tempWeaponBlade = WeaponItems(name: "Weapon Blade", index: 0, price: 300)
tempWeaponBlade.weaponPower = 15
return tempWeaponBlade
}
}
var swiftShooter:WeaponItems{
get {
let tempSwiftShooter = WeaponItems(name: "Swift Shooter", index: 1, price: 300)
tempSwiftShooter.attackSpeed = 0.2
return tempSwiftShooter
}
}
var minionsFoot:WeaponItems{
get {
let tempMinionsFoot = WeaponItems(name: "Minions Foot", index: 3, price: 300)
tempMinionsFoot.criticalChance = 0.1
tempMinionsFoot.criticalDamage = 0.1
return tempMinionsFoot
}
}
init(name: String, index: Int, price: Int){
self.name = name
self.index = index
self.price = price
}
}

Answer 2

If you wish to have default property values, which you would also like the opportunity to customise when creating an instance, then I would recommend using default parameter values in your initialiser. This will allow you to create a new instance of your WeaponItems class with the actual property values known at initialisation, rather than some default values which you then change immediately after.
I also strongly agree with Luca D'Alberti – there is no need for your 'preset weapons' to be instance properties. As they don't rely on any instance state, or are unique to a given instance – they should be static.
For example:
class Weapon {
static var blade : Weapon {
return Weapon(name: "Blade", index: 0, price: 300, power: 15)
}
static var swiftShooter : Weapon {
return Weapon(name: "Swift Shooter", index: 1, price: 300, attackSpeed: 0.2)
}
static var minionsFoot : Weapon {
return Weapon(name: "Minions Foot", index: 3, price: 300, criticalChance: 0.1, criticalDamage: 0.1)
}
var name: String
var index: Int
var price: Int
var power: Int
var attackSpeed: Double
var criticalChance: Double
var criticalDamage: Double
init(name: String, index: Int, price: Int,
power: Int = 0, attackSpeed: Double = 0,
criticalChance: Double = 0, criticalDamage: Double = 0) {
self.name = name
self.index = index
self.price = price
self.power = power
self.attackSpeed = attackSpeed
self.criticalChance = criticalChance
self.criticalDamage = criticalDamage
}
}
let blade = Weapon.blade
let swiftShooter : Weapon = .swiftShooter

Answer 3

In your case, if the code would compile, to use your pre-created weaponBlade, you have to create two WeaponItems instances as below:
let balde = WeaponItems(name: "", index: 0, price: 0).weaponBlade
That's not the best solution, even because in your case doesn't compile at all (you can read the comment by #gnasher729 to understand why).
What I suggest you is to create static instances of them
extension WeaponItems {
static var Blade: WeaponItems {
get {
let blade = WeaponItems(name: "The name", index: 1, price: 300)
blade.weaponPower = 15
return blade
}
}
}
And you can now use the blade by typing WeaponItems.Blade, or if it the type is easily inferred as below:
let blade: WeaponItems = .Blade

Answer 4

You can try using like below code.
lazy var weaponBlade:WeaponItems = {
let _weaponBlade = WeaponItems(name: "Weapon Blade", index: 0, price: 300)
_weaponBlade.weaponPower = 15
return _weaponBlade
}()
Please refer this link to know more about lazy variable.