Question 1: What is Java?
- An operating system
- A programming language
- A database
- A web browser
Explanation: Java is a high-level programming language.
Core Java Quiz ( Beginner ) - All Questions
This beginner-level Core Java quiz is designed for students and developers starting their Java programming journey. It covers Java fundamentals such as JVM, JDK, data types, variables, operators, OOP basics, control statements, and core syntax—ideal for learning and entry-level interviews.
Question 2: Who developed Java?
- Microsoft
- Sun Microsystems
- IBM
Explanation: Java was developed by Sun Microsystems.
Question 3: Which file extension is used for Java source files?
- .js
- .class
- .java
- .jar
Explanation: Java source files use the .java extension.
Question 4: Which component runs Java bytecode?
- JDK
- JRE
- JVM
- Compiler
Explanation: JVM executes Java bytecode.
Question 5: What does JDK stand for?
- Java Deployment Kit
- Java Development Kit
- Java Design Kit
- Java Debug Kit
Explanation: JDK stands for Java Development Kit.
Question 6: Which keyword is used to define a class in Java?
- function
- define
- class
- struct
Explanation: The class keyword defines a class in Java.
Question 7: Which method is the entry point of a Java program?
- start()
- main()
- run()
- init()
Explanation: main() is the entry point of a Java program.
Question 8: Which access modifier makes members accessible everywhere?
- private
- protected
- default
- public
Explanation: public members are accessible from anywhere.
Question 9: Which keyword is used to create an object?
- create
- new
- object
- alloc
Explanation: Objects are created using the new keyword.
Question 10: Which data type stores whole numbers?
- float
- double
- int
- boolean
Explanation: int is used to store whole numbers.
Question 11: Which data type stores true or false values?
- int
- char
- boolean
- String
Explanation: boolean stores true or false values.
Question 12: Which data type stores a single character?
- String
- char
- int
- boolean
Explanation: char stores a single character.
Question 13: Which keyword is used to inherit a class?
- inherits
- extends
- implements
- super
Explanation: extends is used for class inheritance.
Question 14: Which concept allows one class to acquire properties of another?
- Encapsulation
- Abstraction
- Inheritance
- Polymorphism
Explanation: Inheritance allows property reuse.
Question 15: Which OOP concept hides implementation details?
- Inheritance
- Polymorphism
- Encapsulation
- Compilation
Explanation: Encapsulation hides internal details.
Question 16: Which keyword is used to inherit an interface?
- extends
- inherits
- implements
- interface
Explanation: implements is used to implement interfaces.
Question 17: Which loop executes at least once?
- for
- while
- do-while
- foreach
Explanation: do-while executes at least once.
Question 18: Which loop is best when number of iterations is known?
- while
- do-while
- for
- if
Explanation: for loop is ideal when iterations are known.
Question 19: Which statement is used for decision making?
- for
- switch
- break
- continue
Explanation: switch is used for decision making.
Question 20: Which keyword exits a loop immediately?
- stop
- exit
- continue
- break
Explanation: break exits the loop.
Question 21: Which keyword skips current iteration of a loop?
- skip
- break
- pass
- continue
Explanation: continue skips current iteration.
Question 22: Which operator is used for equality check?
- =
- ==
- !=
- <>
Explanation: == checks equality.
Question 23: Which operator performs logical AND?
- &
- &&
- |
- ||
Explanation: && is logical AND.
Question 24: Which keyword refers to the current object?
- this
- super
- self
- current
Explanation: this refers to the current object.
Question 25: Which keyword refers to parent class object?
- this
- parent
- super
- base
Explanation: super refers to parent class.
Question 26: Which keyword prevents inheritance?
- static
- final
- private
- const
Explanation: final prevents inheritance.
Question 27: Which keyword prevents method overriding?
- static
- private
- final
- abstract
Explanation: final methods cannot be overridden.
Question 28: Which keyword is used to define a constant?
- static
- final
- const
- immutable
Explanation: final is used for constants.
Question 29: Which feature allows method overloading?
- Inheritance
- Encapsulation
- Polymorphism
- Abstraction
Explanation: Polymorphism allows overloading.
Question 30: What is method overloading?
- Same method name with different parameters
- Same method name with same parameters
- Different method names
- Overriding parent method
Explanation: Overloading uses same name with different parameters.
Question 31: Which feature allows method overriding?
- Inheritance
- Encapsulation
- Compilation
- Packaging
Explanation: Inheritance enables method overriding.
Question 32: What is method overriding?
- Same method in same class
- Child class redefining parent method
- Changing method return type
- Using static methods
Explanation: Overriding redefines parent method.
Question 33: Which keyword is used to create an abstract class?
- interface
- virtual
- abstract
- extends
Explanation: abstract keyword defines abstract class.
Question 34: Can we create object of abstract class?
- Yes
- No
- Only once
- Only in main
Explanation: Abstract classes cannot be instantiated.
Question 35: Which keyword is used to define an interface?
- class
- abstract
- implements
- interface
Explanation: interface keyword defines an interface.
Question 36: Can an interface have variables?
- No
- Yes, public static final by default
- Yes, private only
- Yes, dynamic
Explanation: Interface variables are public static final.
Question 37: Which package is automatically imported in Java?
- java.util
- java.io
- java.lang
- java.net
Explanation: java.lang is auto-imported.
Question 38: Which class is parent of all classes?
- Main
- Base
- Object
- Class
Explanation: Object is the root class.
Question 39: Which keyword handles exceptions?
- error
- catch
- throw
- exception
Explanation: catch handles exceptions.
Question 40: Which block is always executed?
- try
- catch
- throw
- finally
Explanation: finally block always executes.
Question 41: Which keyword explicitly throws an exception?
- throws
- catch
- throw
- exception
Explanation: throw explicitly throws an exception.
Question 42: Which keyword declares exceptions?
- throw
- throws
- catch
- final
Explanation: throws declares exceptions.
Question 43: Which Java feature supports platform independence?
- Compiler
- JVM
- JDK
- JRE
Explanation: JVM enables platform independence.
Question 44: Which concept bundles data and methods?
- Inheritance
- Encapsulation
- Polymorphism
- Abstraction
Explanation: Encapsulation bundles data and methods.
Question 45: Which Java keyword is used for memory cleanup?
- delete
- free
- gc
- finalize
Explanation: finalize is called before garbage collection.
Question 46: Which mechanism automatically frees unused memory?
- Destructor
- Garbage Collection
- Manual delete
- Heap cleanup
Explanation: Garbage Collection frees unused memory.
Question 47: Which collection does not allow duplicate values?
- List
- ArrayList
- Set
- Map
Explanation: Set does not allow duplicates.
Question 48: What is the main goal of Core Java?
- UI design
- Building scalable applications
- Learning frameworks
- Database management
Explanation: Core Java builds strong programming foundation.
Core Java Quiz ( Beginner )
This beginner-level Core Java quiz is designed for students and developers starting their Java programming journey. It covers Java fundamentals such as JVM, JDK, data types, variables, operators, OOP basics, control statements, and core syntax—ideal for learning and entry-level interviews.
15
Questions
~15
Minutes
15
Min Limit