Question

Explain the key differences between using if statements to check for null values and using Optional types and why we might prefer that latter.

Answer 1

The if-else statement allows us to select between two alternatives. First, the condition is evaluated. If the result of the evaluation is the value true, the then-statement is executed, otherwise, the else statement is executed. An Optional is essentially a container. It is designed either to store a value or to be "empty" if the value is non-existent - a replacement for the null value. This means that explicit null-checking is no longer needed from a programmer's point of view - it becomes enforced by the language itself.

So the latter one is preferred since it makes your code more readable and protects it against null pointer exceptions. So Never Assign Null to an Optional Variable. Prefer Optional.empty()to initialize anOptional instead of a nullvalue. Optional is just a container/box and it is pointless to initialize it with null. When you have anOptionaland need anullreference, then use orElse(null). Otherwise, avoid orElse(null). A typical scenario for usingorElse(null)occurs when we have anOptionaland we need to call a method that acceptsnullreferences in certain cases. The purpose of Optional is not to replace every single null reference in your codebase but rather to help design better APIs in which—just by reading the signature of a method—users can tell whether to expect an optional value. In addition, Optional forces you to actively unwrap an Optional to deal with the absence of a value; as a result, you protect your code against unintended null pointer exceptions.