Swift's guard keyword

Question

Swift 2 introduced the guard keyword, which could be used to ensure that various data is configured ready to go. An example I saw on this website demonstrates a

Answer 1

Simply put, it provides a way to validate fields prior to execution. This is a good programming style as it enhances readability. In other languages, it may look like this:

func doSomething() {
    if something == nil {
        // return, break, throw error, etc.
    }
    ...
}

But because Swift provides you with optionals, we can't check if it's nil and assign its value to a variable. In contrast, if let checks that it's not nil and assigns a variable to hold the actual value. This is where guard comes into play. It gives you a more concise way of exiting early using optionals.