java 8 interview questions

Java 8 ships with several new features, but the most significant are the following:

• Lambda Expressions − a new language feature allowing us to treat actions as objects


• Method References − enable us to define Lambda Expressions by referring to methods directly using their names


• Optional − special wrapper class used for expressing optionality


• Functional Interface – an interface with maximum one abstract method; implementation can be provided using a Lambda Expression


• Default methods − give us the ability to add full implementations in interfaces besides abstract methods


• Nashorn, JavaScript Engine − Java-based engine for executing and evaluating JavaScript code


• Stream API − a special iterator class that allows us to process collections of objects in a functional manner


• Date API − an improved, immutable JodaTime-inspired Date API

Along with these new features, lots of feature enhancements are done under the hood at both the compiler and JVM level.