1. What is Java 8 ?
Ans: It is a major feature release of Java Programming Language.
2. What are the new features of the Java 8 ?
a. Lambda expression
b. Method references
c. Default method
d. Stream API
e. Date Time API
3. What is Lambda expression ?
Ans: Adds functional processing capability to java
4. What is the use of the method references ?
Ans: Referencing functions by their names instead of invoking them directly
5. What is default method ?
Ans: Interface to have default method implementation.
6. What is jdeps ?
Ans: It is a compiler tools which are used to figure out dependencies.
7. What is the use of the stream API ?
Ans: It is used to facilitate pipeline processing.
8. What is date time API ?
Ans: Improved date time API
10. What is the use of the sortusingjava8() method ?
Ans: Uses sort function with a lambda expression as parameter to get the sorting criteria.
11. What are the three popular java editors ?
12. What are the important characteristics of a lambda expression ?
1. optional type declaration
2. optional parenthesis around parameter
3. optional curly braces
4. optional return keyword
13. How to represent method reference ?
Ans: It is described using “::” symbol.
14. What are the three types of method reference ?
1. Static methods
2. Instance methods
3. Constructors using new operator
15. How to compile java program ?
Ans: Command: javac program-name
16. What is Predicate interface ?
Ans: Predicate <T> interface is a functional interface with a method test (Object) to return a boolean value.
17. What is the use of the default method ?
Ans: Java 8 introduces default method so that list/collection interface can have a default implementation of foreach method and the class implementing these interfaces need not implement the same.
18. What is stream ?
Ans: Stream is a new abstract layer method introduced in java 8. It is a sequence of objects from a source which supports aggregate operations.
19. What are the two methods to generate stream ?
20. What is stream() ?
Ans: Returns a sequential stream considering collection as its source.
21. What is parallelstream () ?
Ans: Returns a parallel stream considering collection as its source.
22. How to iterate each element of the stream ?
Ans: Using forEach method
23. What is map method ?
Ans: The map method is used to map each element to its corresponding result.
24. What is filter method ?
Ans: The filter method is used to eliminate elements based on a criteria.
25. What is limit method ?
Ans: The limit method is used to reduce the size of the stream.
26. What is collectors ?
Ans: Collectors are used to combine the result of processing on the elements of a stream.
27. What is the use of the collectors ?
Ans: It can be used to return a list or a string.
28. What is optional objects ?
Ans: Optional objects is a container object used to contain not-null objects.
29. What is the use of the optional objects ?
Ans: Optional object is used to represent null with absent value.
30. What is JJS ?
31. What is the advantage of the chrono units enum ?
Ans: It is added in java 8 to replace the integer values used in old API to represent day, month etc.
32. What is the use of the temporaladjuster ?
Ans: TemporalAdjusters is used to perform the date mathematics.
33. What is toInstant() method ?
Ans: A toInstant() method is added to the original date and calendar objects which can be used to convert them to the new date-time API.
34. What are the three types of inbuilt encoder and decoder for base64 encoding ?
Ans: There are three types of inbuilt encoder and decoder for base64 encoding