How to link a boolean value to the on/off state of a UISwitch?

Question

I have a UISwitch that I want to control a boolean value in a function I wrote. I looked in the UISwitch Type Reference and it listed the property

Answer 1

Add the UISwitch Reference into ViewController.swift file.

@IBOutlet var mySwitch: UISwitch 
@IBOutlet var switchState: UILabel

then add the target event into the viewdidload method like below

mySwitch.addTarget(self, action: #selector(ViewController.switchIsChanged(_:)), forControlEvents: UIControlEvents.ValueChanged)

When the switch is flipped the UIControlEventValueChanged event is triggered and the stateChanged method will be called.

func switchIsChanged(mySwitch: UISwitch) {
    if mySwitch.on {
        switchState.text = "UISwitch is ON"
    } else {
        switchState.text = "UISwitch is OFF"
    }
}

Swift 3.0

func switchIsChanged(mySwitch: UISwitch) {
    if mySwitch.isOn {
        switchState.text = "UISwitch is ON"
    } else {
        switchState.text = "UISwitch is OFF"
    }
}

Swift 4.0

@objc func switchIsChanged(mySwitch: UISwitch) {
    if mySwitch.isOn {
        switchState.text = "UISwitch is ON"
    } else {
        switchState.text = "UISwitch is OFF"
    }
}

find brief tutorial in http://sourcefreeze.com/uiswitch-tutorial-using-swift-in-ios8/