15+ Best Java 8 Interview Questions Answers - Algrim.co

15+ Best Java 8 Interview Questions Answers - Algrim.co are equally valid. This is known as optional return statement. All Lambda expressions can have all or some of these characteristics. 14. What is Nashorn? In Java 8, Nashorn is a new JavaScript processing engine for the platform. Up until JDK 7, Hava’s platform used Mozilla Rhino as a JavaScript processing engine. Nashorn is an improvement because it allows for better compliance with the ECMA normalized JavaScript specification as well as better performance in runtime. 15. What is the difference between map and flatMap in stream operations? A flatMap operation in Optional would return a String type, while a map operation would return an Optional type due to the difference in the signature. A map operation wraps return values inside the ordinal type and flatMap does not do this.