What is the purpose of the Optional class in Java?

a) To represent the presence or absence of a value

b) To create a lambda expression

c) To throw exceptions

d) To create collections

Answer:

a) To represent the presence or absence of a value

Explanation:

The Optional class in Java is used to represent the presence or absence of a value, helping to avoid NullPointerException by providing a way to handle potentially null values gracefully. The Optional class provides methods to check for the presence of a value, retrieve the value if present, or specify a default value if the Optional is empty. Here is an example:

Optional<String> optionalName = Optional.ofNullable(null); String name = optionalName.orElse("Unknown");  // name is "Unknown"

In this example, the Optional contains a null value, so the orElse method provides a default value. The Optional class encourages developers to think about the presence or absence of values explicitly, leading to more robust and error-resistant code.

Using the Optional class is considered a best practice in modern Java development, as it promotes safer handling of null values and reduces the risk of runtime exceptions. This approach leads to cleaner and more maintainable code, particularly in large and complex applications.