Optionals

Optionals may seem a little complicated at first glance, but actually they are fairly simple. This page is intended to help you decide if you should use an optional, and if so, in what way

When declaring variables

You know the value for the variable at the point it is declared or the class is initialised, and that variable will always have a value

Do not use an optional

//set value at declaration
var myString = "abc"
    
//alternatively set value on class initialisation (using designated initialiser)
var someString : String
init(){
    someString = "abc"
}

You do not have a value for the variable when you declare it, but you can guarantee that whenever you access it, it will have a value

Declare the variable as an implicitly unwrapped optional and use it as normal

var myString : String!

Regardless of whether or not you know the value of a variable when you declare it, you know at some point when you access it, it may not have a value

Declare it as an optional

var myString : String?

When using optionals

At the point of use, you know the optional will have a value

Force Unwrap it

var actualString = myString!

At point of use the optional may not have a value

Check it is not nil first, e.g.:

if let actualString = myString{
 //do something with actualString
 }