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Java Multithreading
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Java Networking
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Java Miscellaneous
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Java APIs & Frameworks
Java Class References
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- Java - Properties
- Java - Collection
- Java - Array
Java Useful Resources
Java 8 Mock Test
This section presents you various set of Mock Tests related to Java 8. You can download these sample mock tests at your local machine and solve offline at your convenience. Every mock test is supplied with a mock test key to let you verify the final score and grade yourself.

Java 8 Mock Test III
Q 1 - Which of the following functional interface represents an operation on a single operand that produces a result of the same type as its operand?
Answer : C
Explanation
UnaryOperator<T> functional interface represents an operation on a single operand that produces a result of the same type as its operand.
Q 2 - Which of the following is correct about default methods?
A - With java 8, an interface can have default implementation of a function in interfaces.
B - An interface can also have static helper methods from Java 8 onwards.
Answer : C
Explanation
Both of the above options are correct.
Q 3 - How will you call a default method of an interface in a class?
A - Using super keyword along with interface name.
Answer : A
Explanation
Using super keyword along with interface name.
Q 4 - How will you call a static method of an interface in a class?
A - Using super keyword along with interface name.
Answer : B
Explanation
Using name of the interface.
Q 5 - Which of the following is correct about streams in java8?
A - Stream represents a sequence of objects from a source, which supports aggregate operations.
B - Most of the stream operations return stream itself so that their result can be pipelined.
Answer : C
Explanation
Both of the above options are correct.
Q 6 - Which of the following is correct about streams in java8?
Answer : C
Explanation
Both of the above options are correct.
Q 7 - What is the purpose of forEach method of stream in java 8?
A - Iterate each element of the stream.
B - Map each element to its corresponding result.
Answer : A
Explanation
Stream has provided a new method 'forEach' to iterate each element of the stream.
Q 8 - What is the purpose of map method of stream in java 8?
A - Iterate each element of the stream.
B - Map each element to its corresponding result.
Answer : B
Explanation
The 'map' method is used to map each element to its corresponding result.
Q 9 - What is the purpose of filter method of stream in java 8?
A - Iterate each element of the stream.
B - Map each element to its corresponding result.
Answer : C
Explanation
The 'filter' method is used to eliminate elements based on a criteria.
Q 10 - What is the purpose of limit method of stream in java 8?
A - Iterate each element of the stream.
B - Map each element to its corresponding result.
Answer : D
Explanation
The 'limit' method is used to reduce the size of the stream.
Q 11 - What is the purpose of sorted method of stream in java 8?
A - Iterate each element of the stream.
B - Map each element to its corresponding result.
Answer : D
Explanation
The 'sorted' method is used to sort the stream.
Q 12 - Which of the following is correct about collectors in java8?
A - Collectors are used to combine the result of processing on the elements of a stream.
Answer : C
Explanation
Both of the above options are correct.
Q 13 - Which of the following is correct about Optional in java8?
A - Optional is a container object which is used to contain not-null objects.
B - Optional object is used to represent null with absent value.
Answer : C
Explanation
Both of the above options are correct.
Q 14 - Which of the following is correct about Optional in java8?
B - It is introduced in Java 8 and is similar to what Optional is in Guava.
Answer : C
Explanation
Both of the above options are correct.
Q 15 - Which of the following is correct about Nashorn in java8?
C - Nashorn uses invokedynamics feature, introduced in Java 7 to improve performance
Answer : D
Explanation
All of the above options are correct.
Answer : A
Explanation
Yes! Using ScriptEngineManager, JavaScript code can be called and interpreted in Java.
Q 17 - Which of the following API represents a simplified date-time API with no complexity of timezone handling in java8?
Answer : A
Explanation
Local − Simplified date-time API with no complexity of timezone handling.
Q 18 - Which of the following API represents a specialized date-time API to deal with various timezones in java8?
Answer : B
Explanation
Zoned − Specialized date-time API to deal with various timezones.
Q 19 - Which of the following class implements a decoder for decoding byte data using the Base64 encoding scheme in Java8?
Answer : A
Explanation
static class Base64.Decoder - This class implements a decoder for decoding byte data using the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.
Q 20 - Which of the following class implements an encoder for encoding byte data using the Base64 encoding scheme in Java8?
Answer : B
Explanation
static class Base64.Encoder - This class implements an encoder for encoding byte data using the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.
Q 21 - Which of the following method of Base64 class returns a Base64.Decoder that decodes using the Basic type base64 encoding scheme?
Answer : A
Explanation
getDecoder() method of Base64 class returns a Base64.Decoder that decodes using the Basic type base64 encoding scheme.
Q 22 - Which of the following method of Base64 class returns a Base64.Encoder that encodes using the Basic type base64 encoding scheme?
Answer : B
Explanation
getEncoder() method of Base64 class returns a Base64.Encoder that encodes using the Basic type base64 encoding scheme.
Q 23 - Which of the following method of Base64 class returns a Base64.Decoder that decodes using the MIME type base64 decoding scheme?
Answer : C
Explanation
getMimeDecoder() method of Base64 class returns a Base64.Decoder that decodes using the MIME type base64 decoding scheme.
Q 24 - Which of the following method of Base64 class returns a Base64.Encoder that encodes using the MIME type base64 encoding scheme?
Answer : D
Explanation
getMimeEncoder() method of Base64 class returns a Base64.Encoder that encodes using the MIME type base64 encoding scheme.
Q 25 - Which of the following method of Base64 class returns a Base64.Decoder that decodes using the URL and Filename safe type base64 encoding scheme?
Answer : A
Explanation
getUrlDecoder() method of Base64 class returns a Base64.Decoder that decodes using the URL and Filename safe type base64 encoding scheme.
Answer Sheet
Question Number | Answer Key |
---|---|
1 | C |
2 | C |
3 | A |
4 | B |
5 | C |
6 | C |
7 | A |
8 | B |
9 | C |
10 | D |
11 | D |
12 | C |
13 | C |
14 | C |
15 | D |
16 | A |
17 | A |
18 | B |
19 | A |
20 | B |
21 | A |
22 | B |
23 | C |
24 | D |
25 | A |