Given:javaOptional optionalName = Optional.

Understanding Optional.ofNullable(null)

Optional.ofNullable(null); creates an empty Optional (i.e., it contains no value).

Optional.of(null); would throw a NullPointerException, but ofNullable(null); safely creates an empty Optional.

Execution of orElse, orElseGet, and orElseThrow

orElse("Baguette")

Since optionalName is empty, "Baguette" is returned.

bread = "Baguette"

Output:"bread:Baguette"

orElseGet(() -> "Frog legs")

Since optionalName is empty, "Frog legs" is returned from the lambda expression.

dish = "Frog legs"

Output:", dish:Frog legs"

orElseThrow(() -> new Exception())

Since optionalName is empty, an exception is thrown.

The catch block catches this exception and prints ", no cheese.".

Thus, the final output is:

makefile

bread:Baguette, dish:Frog legs, no cheese.

References:

Java SE 21 & JDK 21 - Optional

Java SE 21 - Functional Interfaces