Best Java Fundamental Questions & Answer | Free Java Online Test | Synergistic IT

20 Most Popular Quiz Questions on Core Java Java is a high-level object-oriented language that James Gosling developed in the year 1995.

This programming language is used in various scenarios like internet programming, mobile devices, games, and e-business solutions. Java is a significantly simple language with a highly readable syntax that uses English keywords in its code. Java online test will gauge your competence in Java programming, thus helping you transform into an expert Java coder.

So, here is a compilation of core Java online test questions and answers.

1. Java language was initially called Oak” but was renamed Java” in 1995. a. True b. False Answer: a 2. Which of the below are reserved keywords in Java?

a. b. c. d.

goto array int null

Answer: a & c

3. What is the correct syntax to output "Hello World" in Java? a. b. c. d.

Answer: c

print ("Hello World"); Console.WriteLine("Hello World"); System.out.println("Hello World"); echo("Hello World");

4. Unchecked exceptions are checked at compile-time rather they are checked at runtime. a. True b. False Answer: b

5. Which concept of Java is achieved by combining methods and attribute into a class? a. b. c. d.

Inheritance Encapsulation Polymorphism Abstraction

Answer: b

6. Which method returns the interrupted flag, and then sets the flag to false if it is true? a. b. c. d.

isInterrupted() non static interrupted() static interrupted() Both a & b

Answer: c

7. Java can be used to create two types of programs: applications and a. b. c. d.

servlets applets both 1 and 2 none of the above

Answer: b

8. Which of the following statements is a disadvantage of a Java array? a. An array has its size that is known as the array length b. An array can hold primitive types of data c. An array holds only one type of data

d. An array knows only its type that it contains. The array type is checked at the compile time.

Answer: c

9. How do you insert COMMENTS in Java code? a. /* This is a comment b. # This is a comment c. // This is a comment Answer: c

10. Which constructor creates an empty string buffer with the specified capacity as length? a. b. c. d.

StringBuffer(String str) StringBuffer() None of the above StringBuffer(int capacity)

Answer: d

11. How many reserved keywords are currently defined in the Java language? a. b. c. d.

49 48 50 47

Answer: a

12. Which keyword is used to create a class in Java? a. b. c. d.

MyClass className class() class

Answer: d

13. What is the correct way to create an object called myObj of MyClass? a. b. c. d.

class myObj = new MyClass(); new myObj = MyClass(); MyClass myObj = new MyClass(); class MyClass = new myObj();

Answer: c

14. What is the following syntax used for? class Subclass-name extends Superclass-name { //methods and fields } a. b. c. d.

Polymorphism Inheritance Encapsulation None of the above

Answer: b

15. Which constructor creates an empty string buffer with the specified capacity as length? a. b. c. d.

StringBuffer(String str) StringBuffer(int capacity) StringBuffer() None of the above

Answer: b

16. Which Exception occurs when a class is not found while dynamically loading a class using the class loaders? a. NoClassDefFoundError b. ClassFoundException c. ClassNotFoundException

d. ClassDefFoundError Answer: c

17. Packages are used for distributing a collection of reusable classes, usually in a format known as a Java Archive (JAR) file. a. True b. False

Answer: a

18. When Java source code is compiled, each individual class is put into its own output file named after the class and using the .class extension. a. True b. False Answer: a

19. Which method returns a reference to the currently executing thread object? a. b. c. d.

runningThread() currentThread() runnableThread() None of the above

Answer: b

20. Which is a technique in Java in which a class can have any number of constructors that differ in parameter lists? a. b. c. d.

Answer: c

Method overloading Operator overloading Constructor overloading None of the above

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