After setting variable value, it prints as unchanged - ios

Question

I change the value of a variable with this function:
func scoreDisplay(score:Double) {
print(score)
CounterView().counter = Int(score)
print(CounterView().counter)
}
This changes the value of counter in my CounterView class. That class looks like this:
import UIKit
#IBDesignable class CounterView: UIView {
let possiblePoints = 100
let π:CGFloat = CGFloat(M_PI)
var counter: Int = 20
#IBInspectable var outlineColor: UIColor = UIColor.blueColor()
#IBInspectable var counterColor: UIColor = UIColor.orangeColor()
override func drawRect(rect: CGRect) {
// 1
let center = CGPoint(x:bounds.width/2, y: bounds.height/2)
// 2
let radius: CGFloat = max(bounds.width, bounds.height)
// 3
let arcWidth: CGFloat = 76
// 4
let startAngle: CGFloat = 3 * π / 4
let endAngle: CGFloat = π / 4
// 5
var path = UIBezierPath(arcCenter: center,
radius: radius/2 - arcWidth/2,
startAngle: startAngle,
endAngle: endAngle,
clockwise: true)
// 6
path.lineWidth = arcWidth
counterColor.setStroke()
path.stroke()
//Draw the outline
//1 - first calculate the difference between the two angles
//ensuring it is positive
let angleDifference: CGFloat = 2 * π - startAngle + endAngle
//then calculate the arc for each single glass
let arcLengthPerPoint = angleDifference / CGFloat(possiblePoints)
//then multiply out by the actual glasses drunk
let outlineEndAngle = arcLengthPerPoint * CGFloat(counter) + startAngle
//2 - draw the outer arc
var outlinePath = UIBezierPath(arcCenter: center,
radius: bounds.width/2 - 2.5,
startAngle: startAngle,
endAngle: outlineEndAngle,
clockwise: true)
//3 - draw the inner arc
outlinePath.addArcWithCenter(center,
radius: bounds.width/2 - arcWidth + 2.5,
startAngle: outlineEndAngle,
endAngle: startAngle,
clockwise: false)
//4 - close the path
outlinePath.closePath()
outlineColor.setStroke()
outlinePath.lineWidth = 5.0
outlinePath.stroke()
}
}
The score is being passed in properly, and prints the correct value - the problem is that as soon as I change the value of CounterView().counter I try to print it out, but it returns as 20 even though I just set the value to a different number.

Answer 1

It's pretty simple.
You create a new instance of CounterView every time you write
CounterView()
So, with your code
CounterView().counter = Int(score)
print(CounterView().counter)
you have created 2 instances of CounterView. The print function is called on the newly created CounterView so its counter value is the default value you set in the implementation: 20. You need to store the instance in a local variable. For example, your method could look like this
func scoreDisplay(score:Double) {
print(score)
let counterView = CounterView()
counterView.counter = Int(score)
print(counterView.counter)
}

Answer 2

This expression
CounterView().counter
creates a new instance of CounterView each time it's called.
You should create one instance, save it in a variable and access counter from that instance.