Question 1: What is the output of the following Java code?

public class Main {
    public static void main(String[] args) {
        int x = 5;
        System.out.println(x++);
    }
}
        

1. 5
2. 6
3. 0
4. 1

Question 2: Which access modifier is not allowed for top-level classes in Java?

1. public
2. private
3. protected
4. default (package-private)

Question 3: What is the keyword used to define a constant in Java?

1. static
2. final
3. constant
4. public

Question 4: What is the purpose of the `break` statement in a Java `switch` statement?

1. To exit the switch statement and continue with the next case.
2. To skip the current case and continue with the default case.
3. To exit the program entirely.
4. To restart the switch statement from the beginning.

Question 5: Which Java keyword is used to create a new instance of a class?

1. new
2. class
3. instance
4. object

Question 6: What is the purpose of the `super` keyword in Java?

1. To call a superclass constructor and access superclass methods or variables.
2. To access the current class’s constructor.
3. To invoke a static method.
4. To break out of a loop or switch statement.

Question 7: What is the difference between `==` and `.equals()` when comparing strings in Java?

1. They are equivalent and can be used interchangeably.
2. `==` compares object references, while `.equals()` compares string contents.
3. `==` compares string contents, while `.equals()` compares object references.
4. Both always return `true` for any strings.

Question 8: What is the purpose of the `try`, `catch`, and `finally` blocks in Java for exception handling?

1. `try` is used to throw an exception, `catch` is used to handle the exception, and `finally` is used for cleanup code.
2. `try` is used to handle an exception, `catch` is used to throw the exception, and `finally` is used for cleanup code.
3. `try` is used to define a block of code to be tested for exceptions, `catch` is used to handle the exception, and `finally` is used for cleanup code.
4. `try` is used to define a block of code to be tested for exceptions, and `catch` is used to define the exception type.

Question 9: What is method overloading in Java?

1. Method overloading is the process of creating a new method with the same name but different parameter types or a different number of parameters within the same class.
2. Method overloading is the process of creating multiple methods with different names but the same parameter types.
3. Method overloading is the process of creating a new method with a different return type in the same class.
4. Method overloading is the process of creating multiple methods with the same name and the same parameter types.

Question 10: What is the purpose of the `this` keyword in Java?

1. `this` is used to create a new object of a class.
2. `this` is used to refer to the current instance of a class.
3. `this` is used to invoke a method in another class.
4. `this` is used to create a static method in a class.

Question 11: What is the difference between `ArrayList` and `LinkedList` in Java?

1. `ArrayList` is a synchronized collection, while `LinkedList` is not.
2. `ArrayList` is faster for random access, while `LinkedList` is faster for inserting and deleting elements.
3. `ArrayList` can only store integers, while `LinkedList` can store any data type.
4. `ArrayList` and `LinkedList` are the same, just with different names.

Question 12: What is the purpose of the `static` keyword in Java?

1. `static` is used to create an instance of a class.
2. `static` is used to define a constant value.
3. `static` is used to create a subclass of a class.
4. `static` is used to define a class-level variable or method that can be accessed without creating an instance of the class.

Question 13: What is the purpose of the `extends` keyword in Java for classes?

1. `extends` is used to create a new class.
2. `extends` is used to implement an interface.
3. `extends` is used to define a superclass-subclass relationship, allowing inheritance of fields and methods.
4. `extends` is used to create a copy of an existing class.

Question 14: What is a constructor in Java?

1. A constructor is a method used for creating new objects.
2. A constructor is used to destroy objects.
3. A constructor is a special type of method used for subclassing.
4. Java does not support constructors.

Question 15: What is the purpose of the `public` access modifier in Java?

1. `public` allows access to the element from within the same class only.
2. `public` restricts access to the element from all other classes.
3. `public` allows access to the element from any class or package.
4. `public` is not a valid access modifier in Java.

Question 16: What is the purpose of the `break` statement in a loop in Java?

1. `break` is used to exit the loop and continue with the next iteration.
2. `break` is used to skip the current iteration and continue with the next one.
3. `break` is used to create an infinite loop.
4. `break` is used to restart the loop from the beginning.

Question 17: What is method overriding in Java?

1. Method overriding is the process of creating multiple methods with the same name but different parameter types in the same class.
2. Method overriding is the process of creating a new method with the same name but different parameter types in a subclass.
3. Method overriding is the process of creating a new method with a different return type in a subclass.
4. Method overriding is not allowed in Java.

Question 18: What is the purpose of the `final` keyword in Java?

1. `final` is used to define a class that cannot be extended.
2. `final` is used to prevent the modification of variables, methods, or classes.
3. `final` is used to make a class abstract.
4. `final` is used to define a class that can only be extended.

Question 19: What is the purpose of the `throws` keyword in Java?

1. `throws` is used to define custom exceptions.
2. `throws` is used to declare that a method may throw exceptions and specify the exception types that the method might throw.
3. `throws` is used to catch exceptions and handle them within a method.
4. `throws` is used to terminate a program.

Question 20: What is the purpose of the `new` keyword in Java?

1. `new` is used to create a new object of a class.
2. `new` is used to create a new class.
3. `new` is used to define a variable.
4. `new` is not a valid keyword in Java.