titleLabel.text vs currentTitle in Swift

Question

I am trying to make a simple calculator with Swift. I want to get the "text" on the buttons I created. The instructor in the tutorial is using a property:

@IBAction func appendDigit(sender: UIButton) {
    let digit = sender.currentTitle
}

The question is, if I did this:

@IBAction func appendDigit(sender: UIButton) {
    let digit = sender.titleLabel.text
}

What's the difference? Will they yield the same results? If so, how does one know when to use which?

Answer 1

titleLabel.text is mainly using to configure the text of the button(for each state)

currentTitle is read only. This is mainly using to get the title that is currently displayed.

You can't set this property because this set automatically whenever the button state changes. You can use currentTitle to get the title string associated with the button instead of using titleLabel.text because currentTitle property is set automatically whenever the button state changes.