Steps

1. How to use Option and Some - a basic example
Let's declare a simple String called glazedDonutTaste. But instead of its type being just a String, you will declare it as an Option of type String using the syntax Option[String].

You can then assign its value using the Some class and pass in your donut taste String of Very Tasty.

println("Step 1: How to use Option and Some - a basic example")
val glazedDonutTaste: Option[String] = Some("Very Tasty")
println(s"Glazed Donut taste = ${glazedDonutTaste.get}")

You should see the following output when you run your Scala application in IntelliJ:

Step 1: How to use Option and Some - a basic example
Glazed Donut taste = Very Tasty

NOTE:

• Because we have wrapped our String into an Option, to retrieve its value we call the get() function as shown above.
• But calling get() in a production system is generally a code smell as you may end up with the same NullPointerException.

2. How to use Option and None - a basic example
Let's use another variable called glazedDonutName which is also an Option of type String. But instead of initializing it to a String which is wrapped up into a Some class as shown in Step 1, let's set its value to None.

println("\nStep 2: How to use Option and None - a basic example")
val glazedDonutName: Option[String] = None
println(s"Glazed Donut name = ${glazedDonutName.getOrElse("Glazed Donut")}")

You should see the following output when you run your Scala application in IntelliJ:

Step 2: How to use Option and None - a basic example
Glazed Donut name = Glazed Donut

NOTE:

• We've used the handy getOrElse() function from the Option to supply a default value.
• If you were to call the get() function as shown in Step 1, you will get the exception java.util.NoSuchElementException: None.get.
• At this point, you may be asking yourself that this exception is similar to your NullPointerException.
• And you are absolutely right! But Pattern Matching is your friend :) let's look at Step 3 below.

3. How to use Pattern Matching with Option

Feel free to review the two previous tutorials Pattern Matching and Tuples.

You've already seen from Step 2 that you can use the getOrElse()  function to get a default value in case your variable had no data.

But you can also use Pattern Matching as shown below:

println("\nStep 3: How to use Pattern Matching with Option")
glazedDonutName match {
  case Some(name) => println(s"Received donut name = $name")
  case None       => println(s"No donut name was found!")
}

You should see the following output when you run your Scala application in IntelliJ:

Step 3: How to use Pattern Matching with Option
No donut name was found!

NOTE:

• Sure, you can argue that we have not achieved much!
• But, let's take a pause and assume that you were calling some function to populate your variable glazedDonutName
• As a consumer of that function call, you would not know that the function could potentially return null.
• What have we learned? It's all about intent!
• By being explicit that such a function will return an Option, any consumer of the function can avoid NullPointerException by using getOfElse() or Pattern Matching.
• Not to worry, we will see examples of functions which return Option in upcoming tutorials.