如何在Swift中保存一次整数？

Question

Im making a game and when the user collects an orb I want it to save in an lael but only once. I got it to save the integer in a label but need help with not letting the the orb be saved more than once. Here is the code Im using:

if firstBody.categoryBitMask == HeroCategory && secondBody.categoryBitMask == OrbCategory {

        //saves orbs

        UserDefaults().set(UserDefaults().integer(forKey: "saveOrbs")+1, forKey:"saveOrbs")
        UserDefaults().integer(forKey: "saveOrbs").description

        orbLabel.text = UserDefaults().integer(forKey: "saveOrbs").description


}

Answer 1

Try checking the key before setting it like

if UserDefaults.standard.value(forKey: "haveSavedOrb")  == nil {
UserDefaults.standard.set(true, forKey: "haveSavedOrb")
UserDefaults.standard.set(orbs + 1, forKey: "saveOrbs")
} 

Answer 2

In Swift 3:

To set the value 100 for the key MyInt

UserDefaults.standard.set(100, forKey: "MyInt")

And later to retrieve the value for MyInt .

let myInt = UserDefaults.standard.integer(forKey: "MyInt")