Optional Class

Optional<T> is a container object which may or may not contain a non-null value. It forces you to think about the case when a value is not present.

Creating Optionals

Optional<String> empty = Optional.empty();
Optional<String> hasValue = Optional.of("Hello");
Optional<String> nullable = Optional.ofNullable(someVariable);

Checking for Value

Instead of if (x != null), use:

if (opt.isPresent()) {
    System.out.println(opt.get());
}

Powerful Methods

• orElse(T other): Returns the value if present, otherwise returns other.
• ifPresent(Consumer c): Execute specific code if value is present.

String name = null;
String result = Optional.ofNullable(name).orElse("Default Name");
System.out.println(result); // "Default Name"

Interactive Code

Fix the null handling!

Quiz

Next Steps

Time to look under the hood again. Module 14: JVM Internals.