500+ Java MCQs
Prepare for your Java interviews and exams with our comprehensive collection of 500+ multiple-choice questions. This resource is designed to help you test and improve your knowledge of Java programming concepts, including core Java, object-oriented programming, data structures, algorithms, and more. Whether you are a beginner or an experienced Java developer, these MCQs will challenge your understanding and help you identify areas for improvement. Each question is carefully crafted to assess your problem-solving skills and critical thinking abilities. With this extensive question bank, you can confidently prepare for any Java-related interview or exam. Take advantage of this valuable resource to enhance your Java expertise and increase your chances of success.
Q1. Who is considered the father of Java?
A. Dennis Richie
B. Ken Thompson
C. James Gosling
D. Bjarne Stroupstrup
Ans:: C. James Gosling
Q2. Which of the following statements about the Java language is true?
A. Java supports only Procedural Oriented Programming approach
B. Both Procedural and Object Oriented Programming are supported in Java
C. Java supports only Object Oriented Programming approach
D. None of the Above
Ans:: C. Java supports only Object Oriented Programming approach
Q3. JRE stands for
A. Java Realtime Environment
B. Java Rapid Enterprise
C. Java Runtime Environment
D. None of the above
Ans:: C. Java Runtime Environment
Q4. Java source files are compiled and converted to
A. Object code
B. machine code
C. Bytecode
D. executable file
Ans:: C. Bytecode
Q5. JVM is ___________for bytecode.
A. a compiler
B. an interpreter
C. assembler
D. none of the above
Ans:: B. an interpreter
Q6. What is the size of the int data type in Java?
A. 1 byte
B. 2 bytes
C. 4 bytes
D. 8 bytes
Ans:: C. 4 bytes
Q7. Java is a __________ language?
A. Platform Dependent
B. Platform Independent
C. POP
D. Both A & B
Ans:: B. Platform Independent
Q8. In which year Java was developed?
A. 1995
B. 1975
C. 1994
D. 1980
Ans:: A. 1995
Q9. How many access modifiers are present in Java?
A. 1
B. 3
C. 2
D. 4
Ans:: D. 4 (public, private, default, protected)
Q10.Which of the following is not an access modifier in Java?
A. public
B. protected
C. secure
D. private
Ans:: C. Secure
Q11.Which of the following is not an access modifier in Java?
A. public
B. protected
C. secure
D. private
Ans:: C. Secure
Q12.Which is a valid float literal?
A. 1.23
B. 2
C. 1.23d
D. 1.23f
Ans:: D. 1.23f
Q13.Which of these values can a boolean variable contain?
A. True & False
B. 0 & 1
C. Any integer value.
D. Both a & b
Ans:: A. True & False
Q14.What are the types of memory allocated in memory in java?
A. Heap memory
B. Stack memory
C. Both A and B
D. None of these
Ans:: C. Both A and B
Q15.What makes the Java platform independent?
A. Advanced programming language
B. It uses bytecode for execution
C. Class compilation
D. All of these
Ans:: B. It uses bytecode for execution
Q16.Which of these is an incorrect array declaration?
A. int arr[] = new int[5];
B. int [] arr = new int[5];
C. int arr[]; arr = new int[5];
D. int arr[] = int [5] new;
Ans:: D. int arr[] = int [5] new;
Q17.The keyword used to create a constant variable
A. const
B. static
C. final
D. none of these
Ans:: A. final
Q18.What is stored in the object obj in the following lines of code?
Test obj;
A. Memory address of allocated memory of the object.
B. Null
C. Any arbitrary pointer
D. Garbage
Ans:: B. Null
Q19.What is the entry point of a program in Java?
A. main() method
B. The first line of code
C. Last line of code
D. main class
Ans:: A. main() method
Q20.Can the main() method be overloaded in Java?
A. Yes
B. No
Ans:: A. Yes(Note: We can overload the main method in Java but JVM only calls the original main method, it will never call our overloaded main method.)
Q21.Which class in Java is used to take input from the user?
A. Scanner
B. Input
C. Applier
D. None of these
Ans:: A. Scanner
Q22. Is string mutable in Java?
A. Yes
B. No
Ans:: B. No
Q23.Which of these is a type of variable in Java?
A. Instance Variable
B. Local Variable
C. Static Variable
D. All of these
Ans:: D. All of these
Q24. What will be the output of the below program?
public class Test {
public static void main(String[] args) {
String str = "Hello";
str = "World";
System.out.println(str);
}
}
A. Hello
B. World
C. Error
D. None of these
Ans:: B. World
Q25.What is typecasting in Java?
A. It is converting the type of a variable from one type to another
B. Casting variable to the class
C. Creating a new variable
D. All of these
Ans:: A. It is converting the type of a variable from one type to another
Q26.Which class cannot have a subclass in Java?
A.abstract class
B.parent class
C.final class
D.None of the above
Ans:: C. final class (We can not extend a class if it is a final class)
Q27.Which is the keyword used to inherit a class from another class?
A.Inherits
B.implements
C.extends
D.import
Ans:: B. extends
Q28.What is the use of the final keyword with method definition?
A.to supports method overriding
B.implements dynamic method dispatch
C.Prevent method overriding
D.None of these
Ans:: C.Prevent method overriding
Q29.Identify the type of inheritance when two or more subclasses inherit the properties of a super class.
A.Multiple inheritance
B.Single inheritance
C.Multilevel inheritance
D.Hierarchical inheritance
Ans:: D. Hierarchical inheritance
Q30.Which keyword is used inside a class to refer to its immediate super class?
A.super
B.parent
C.base
D.none of these
Ans:: A. super
Q31.Which of the following is true in the case of abstract class?
A. Abstract constructors cannot be created.
B. Abstract classes can not be inherited.
C. An abstract class contains only abstract methods.
D. All of the above.
Ans:: A. Abstract constructors cannot be created.
Q32. Which of these keywords are used to define an abstract class?
A. abst
B. abstract
C. Abstract
D. abstract class
Ans:: B. abstract
Q33. Which of these is not a correct statement?
A. Every class containing abstract method must be declared abstract.
B. Abstract class defines only the structure of the class not its implementation.
C. Abstract class can be initiated by new operator.
D. Abstract class can be inherited.
Ans:: C. Abstract class can be initiated by new operator.
Q34. Which method defined in the Integer class can be used to convert a whole number in string type to primitive int type?
A. valueOf()
B. intValue()
C. parseInt()
D. getInteger()
Ans:: C. parseInt()
Q35.The method sqrt() is defined in the class
A. System
B. Root
C. Math
D. Arithmetic
Answer» C. Math
Q36. Name the keyword that makes a variable belong to a class, rather than being defined for each instance of the class.
A. static
B. final
C. abstract
D. public
Ans:: A. static
Q37. Variables declared within a class are called
A. Identifier
B. local variable
C. instance variable
D. global variable
Ans:: C. instance variable
Q38. Variables declared within a method or block are called
A. Static variable
B. local variable
C. instance variable
D. global variable
Ans:: B. local variable
Q39. Defining methods with the same name and different numbers of parameters are called
A. Method overriding
B. method overloading
C. Dynamic method dispatch
D. none of the above
Ans:: B. method overloading
Q40. Which is used to initialize the objects.
A. Methods
B. arguments
C. constructors
D. new keyword
Ans:: C. constructors
Q41. What is the return type of Constructors?
A. int
B. float
C. void
D. None of the these
Ans:: D. None of the these
Q42. Which of the following is a method having the same name as that of its class?
A. finalize
B. delete
C. class
D. constructor
Ans:: D. constructor
Q43. Which operator is used by Java run time implementations to free the memory of an object when it is no longer needed?
A. delete
B. free
C. new
D. None of these
Ans:: D. None of these
Q44. Which of these access specifiers must be used for main() method?
A. private
B. public
C. protected
D. None of these
Ans:: B. public
Q45. Which of these is used to access the member of a class before the object of that class is created?
A. public
B. private
C. static
D. protected
Ans:: C. static
Q46. Which keyword is used to create an object?
A. class
B. this
C. new
D. malloc
Ans:: C. new
Q47. Which keyword is used to refer to the current object?
A. class
B. this
C. new
D. malloc
Ans:: B. this
Q48. A Method that is automatically invoked during garbage collection.
A. destructor
B. terminate()
C. finalize()
D. destroy()
Ans:: C. finalize()
Q49. A primitive data type can be passed as an argument into a method.
A. By Value
B. by reference
C. both a & b
D. None of these
Ans:: A. By Value
Q50. Which of these is used as a default for a member of a class if no access specifier is used for it?
A. private
B. public
C. public, within its own package
D. protected
Ans:: C. public, within its own package
Q51. Which of these keywords is used to refer to a member of the base class from a sub-class?
A. upper
B. super
C. this
D. None of these
Ans:: B. super
Q52. Which of these is the correct way of inheriting class A by class B?
A. class B + class A {}
B. class B inherits class A {}
C. class B extends A {}
D. class B extends class A {}
Ans:: C. class B extends A {}
Q53. Which of the following statements are true about interfaces?
A. Methods declared in interfaces are implicitly private.
B. Variables declared in interfaces are implicitly public, static, and final.
C. An interface contains any number of method definitions.
D. The keyword implements indicate that an interface inherits from another.
Ans:: B. Variables declared in interfaces are implicitly public, static, and final.
Q54. Which of these keywords is used to define interfaces in Java?
A. interface
B. Interface
C. intface
D. implements
Ans:: A. interface
Q55. Which of these can be used to fully abstract a class from its implementation?
A. Objects
B. Packages
C. Interfaces
D. None of these
Ans:: C. Interfaces
Q56. Which of these access specifiers can be used for an interface?
A. Public
B. Protected
C. private
D. All of these
Ans:: A. Public
Q57. Which of these keywords is used by a class to use an interface defined previously?
A. import
B. Import
C. implements
D. Implements
Ans:: C. implements
Q58. Which of the following is the correct way of implementing an interface Department by a class Employee?
A. class Employee extends Department{}
B. class Employee implements Department{}
C. class Employee imports Department{}
D. None of these
Ans:: B. class Employee implements Department{}
Q59. Which keyword is used to create a package?
A. import
B. package
C. classpath
D. public
Ans:: B. package
Q60. The modifier which specifies that the member can only be accessed in its own class is.
A. public
B. private
C. protected
D. None of these
Ans:: B. private