Java Programming

Q 1. Who invented Java Programming?
A. Guido van Rossum
B. Bjarne Stroustrup
C. Dennis Ritchie
D. James Gosling

Show Answer

Answer:-D. James Gosling

Explanation

Java programming was developed by James Gosling at Sun Microsystems in 1995. James Gosling is well known as the father of Java.

Q 2. Which statement is true about Java?
A. Java is a platform-independent programming language
B. Java is a code dependent programming language
C. Java is a platform-dependent programming language
D. Java is a sequence-dependent programming language

Show Answer

Answer:- A. Java is a platform-independent programming language

Explanation

Java is called ‘Platform Independent Language’ as it primarily works on the principle of ‘compile once, run everywhere’.

Q 3. Which component is used to compile, debug and execute the java programs?
A. JRE
B. JIT
C. JDK
D. JVM

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Answer:-C. JDK

Explanation

JDK is a core component of Java Environment and provides all the tools, executables and binaries required to compile, debug and execute a Java Program.

Q 4. Which one of the following is not a Java feature?
A. Object-oriented
B. Use of pointers
C. Portable
D. Dynamic and Extensible

Show Answer

Answer:-B. Use of pointers

Explanation

Pointers is not a Java feature. Java provides an efficient abstraction layer for developing without using a pointer in Java. Features of Java Programming are Portable, Architectural Neutral, Object-Oriented, Robust, Secure, Dynamic and Extensible, etc.

Q 5. Which of these cannot be used for a variable name in Java?
A. identifier & keyword
B. keyword
C. identifier
D. none of the mentioned

Show Answer

Answer:-B. keyword

Explanation

Keywords are specially reserved words that can not be used for naming a user-defined variable, for example: class, int, for, etc.

Q 6. What is the extension of java code files?
A .js
B .txt
C .class
D .java

Show Answer

Answer:-D .java

Explanation

Java files have .java extension.

Q 8. Which environment variable is used to set the java path?
A. MAVEN_Path
B. JavaPATH
C. JAVA
D. JAVA_HOME

Show Answer

Answer:-D. JAVA_HOME

Explanation

JAVA_HOME is used to store a path to the java installation.

Q 9. Which of the following is not an OOPS concept in Java?
A. Polymorphism
B. Inheritance
C. Compilation
D. Encapsulation

Show Answer

Answer:-C. Compilation

Explanation

There are 4 OOPS concepts in Java. Inheritance, Encapsulation, Polymorphism and Abstraction.

Q 10. What is not the use of “this” keyword in Java?
A. Referring to the instance variable when a local variable has the same name
B. Passing itself to another method
C. Passing itself to the method of the same class
D. Calling another constructor in constructor chaining

Show Answer

Answer:-C. Passing itself to the method of the same class

Explanation

“this” is an important keyword in java. It helps to distinguish between local variable and variables passed in the method as parameters.

Q 11. What will be the error in the following Java code?

    byte b = 50;
    b = b * 50;

A. * operator has converted b * 50 into int, which can not be converted to byte without casting
B. b cannot contain value 100, limited by its range
C. No error in this code
D. b cannot contain value 50

Show Answer

Answer:-A. * operator has converted b * 50 into int, which can not be converted to byte without casting

Explanation

While evaluating an expression containing int, bytes or shorts, the whole expression is converted to int then evaluated and the result is also of type int.

Q 12 . Which of the following is a type of polymorphism in Java Programming?
A. Multiple polymorphism
B. Multilevel polymorphism
C. Compile time polymorphism
D. Execution time polymorphism

Show Answer

Answer:-C. Compile time polymorphism

Explanation

There are two types of polymorphism in Java. Compile time polymorphism (overloading) and runtime polymorphism (overriding).

Q 13 . What is Truncation in Java?
A. Floating-point value assigned to a Floating type
B. Floating-point value assigned to an integer type
C. Integer value assigned to floating type
D. Integer value assigned to floating type

Show Answer

Answer:-B. Floating-point value assigned to an integer type

Q 14 . What is the extension of compiled java classes?
A. .txt
B. .js
C. .class
D. .java

Show Answer

Answer:-C. .class

Explanation

The compiled java files have .class extension.

Q 15 . Which exception is thrown when java is out of memory?
A. OutOfMemoryError
B. MemoryError
C. MemoryOutOfBoundsException
D. MemoryFullException

Show Answer

Answer:-A. OutOfMemoryError

Explanation

The Xms flag has no default value, and Xmx typically has a default value of 256MB. A common use for these flags is when you encounter a java.lang.OutOfMemoryError.

Q 16 . Which of these are selection statements in Java?
A. break
B. continue
C. for()
D. if()

Show Answer

Answer:- D. if()

Explanation

Continue and break are jump statements, and for is a looping statement.

Q 17. Which of these keywords is used to define interfaces in Java?
A. intf
B. Intf
C. Interface
D. interface

Show Answer

Answer:-D. interface

Explanation

interface keyword is used to define interfaces in Java.

Q 18 . Which of the following is a superclass of every class in Java?
A. ArrayList
B. Object class
C. Abstract class
D. String

Show Answer

Answer:- B. Object class

Explanation

Object class is superclass of every class in Java.

Q 19. Which of the below is not a Java Profiler?
A. JProfiler
B. JVM
C. Eclipse Profiler
D. JConsole

Show Answer

Answer:- B. JVM

Explanation

Memory leak is like holding a strong reference to an object although it would never be needed anymore. Objects that are reachable but not live are considered memory leaks. Various tools help us to identify memory leaks.

Q 20. Which of these packages contains the exception Stack Overflow in Java?
A. java.lang
B. java.system
C. java.io
D. java.util

Show Answer

Answer:-A. java.lang

Q 21. Which of these statements is incorrect about Thread?
A. start() method is used to begin execution of the thread
B. A thread can be formed by a class that extends Thread class
C. A thread can be formed by implementing Runnable interface only
D. run() method is used to begin execution of a thread before start() method in special cases

Show Answer

Answer:-D. run() method is used to begin execution of a thread before start() method in special cases

Explanation

run() method is used to define the code that constitutes the new thread, it contains the code to be executed. start() method is used to begin execution of the thread that is execution of run(). run() itself is never used for starting execution of the thread.

Q 22. Which of these keywords are used for the block to be examined for exceptions?
A. check
B. throw
C. try
D. catch

Show Answer

daily Answer:-C. try

Explanation

try is used for the block that needs to checked for exception.

Q 23. Which one of the following is not an access modifier?
A. Void
B. Protected
C. Public
D. Private

Show Answer

daily Answer:-A. Void

Explanation

Public, private, protected and default are the access modifiers.

Q 24 . What is the numerical range of a char data type in Java?
A. 0 to 256
B. 0 to 65535
C. -128 to 127
D. 0 to 32767

Show Answer

daily Answer:-B. 0 to 65535

Explanation

Char occupies 16-bit in memory, so it supports 216 i:e from 0 to 65535.

Q 25. Which class provides system independent server side implementation?
A. Server
B. ServerSocket
C. Socket
D. ServerReader

Show Answer

daily Answer:-B. ServerSocket

Explanation

ServerSocket is a java.net class which provides system independent implementation of server side socket connection.

Q 26. Which of the following is true about servlets?
A. Servlets can use the full functionality of the Java class libraries
B. Servlets execute within the address space of web server, platform independent and uses the functionality of java class libraries
C. Servlets execute within the address space of web server
D. Servlets are platform-independent because they are written in java

Show Answer

daily Answer:-B. Servlets execute within the address space of web server, platform independent and uses the functionality of java class libraries

Explanation

Servlets execute within the address space of a web server. Since it is written in java it is platform independent. The full functionality is available through libraries.