I am building a swift game and a need to set up a highscore , i have been trying to figure out how to do it for a while. So please can you tell me how to search this library to
Create a new iOS project in Xcode by using the Single View Application template. Then, replace the content of ViewController.swift
with the following code:
import UIKit
class ViewController: UIViewController {
var generator = [6, 12, 8].generate()
override func viewDidLoad() {
super.viewDidLoad()
let button = UIButton(type: .System)
button.setTitle("Button", forState: .Normal)
button.addTarget(self, action: "newScore", forControlEvents: .TouchUpInside)
button.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(button)
// Auto layout code using anchors (requires iOS9+)
let horizontalConstraint = button.centerXAnchor.constraintEqualToAnchor(view.centerXAnchor)
let verticalConstraint = button.centerYAnchor.constraintEqualToAnchor(view.centerYAnchor)
NSLayoutConstraint.activateConstraints([horizontalConstraint, verticalConstraint])
// Print NSUserDefaults's highscore value when app is launched
print("highscore:", NSUserDefaults.standardUserDefaults().integerForKey("highscore"))
}
func newScore() {
guard let score = generator.next() else { return }
print("current score:", score)
//Check if score is higher than NSUserDefaults stored value and change NSUserDefaults stored value if it's true
if score > NSUserDefaults.standardUserDefaults().integerForKey("highscore") {
NSUserDefaults.standardUserDefaults().setInteger(score, forKey: "highscore")
NSUserDefaults.standardUserDefaults().synchronize()
}
print("highscore:", NSUserDefaults.standardUserDefaults().integerForKey("highscore"))
}
}
Build and run the project on your iPhone or on the simulator. The Xcode console will print 0, which is the current value for NSUserDefaults.standardUserDefaults().integerForKey("highscore")
.
Now, click on the button. This will set the value of score
to 6
and, because 6 > 0
, NSUserDefaults.standardUserDefaults().integerForKey("highscore")
will get this new value.
Click once again on the button. This will set the value of score
to 12
. You will immediately see in the console that NSUserDefaults.standardUserDefaults().integerForKey("highscore")
gets this new value.
Now, if you change the value of score
to 8
by clicking on the button, you will see that NSUserDefaults.standardUserDefaults().integerForKey("highscore")
still has a value of 12
because 8 < 12
.
If you rebuild your project and relaunch it, you will see that NSUserDefaults.standardUserDefaults().integerForKey("highscore")
is persistent (its value is still 12 and has not been reset). Therefore, NSUserDefaults
can be a perfect tool in order to store your players highest scores.
NSUserDefaults.standardUserDefaults().integerForKey("highscore")
always return an Int
(if you haven't set it by yourself, it will return 0
, not nil
). Thus, you dont need to / can't use optional binding with it. If you really want to deal with an optional value return, you will prefer NSUserDefaults.standardUserDefaults().objectForKey("highscore") as? Int
.
var defaults=NSUserDefaults()
var highscore=defaults.integerForKey("highscore")
if(Score>highscore)
{
defaults.setInteger(Score, forKey: "highscore")
}
var highscoreshow=defaults.integerForKey("highscore")
lblHighScore.text="\(highscoreshow)"
println("hhScore reported: \(lblHighScore.text)")
lblPlayScore.text="\(Score)"
println("play reported: \(lblPlayScore.text)")