Java MCQs

    Which of the following will cause a compile-time error?

class Demo {

    static int x = 10;

    int y = 5;

 

    static void test() {

        System.out.println(y);

    }

}

• Error due to static method accessing y
  
  

• No error

• Error in variable declaration

• Error in class declaration

Which of these is true about constructors in Java?

• Constructors must have a return type

• Constructors can be inherited

• Constructors can be overloaded

• You must define at least one constructor

Which is the parent class of all classes in Java?

• Object
  

• Class

• SuperClass

• Base

What happens if you do not provide a constructor in a class?

• Compile error
  

• Java provides a default constructor

• Object cannot be created

• Class won't compile

What is the output?

public class Demo {

    static {

        System.out.println("Static block");

    }

 

    public static void main(String[] args) {

        System.out.println("Main method");

    }

}

• Main method
  

• Static block

• Static block
  Main method

• Compile error

Which block runs first when a class is loaded?

• Constructor
  

• Static block

• Main method

• Instance block

What happens if we try to access a non-static variable from a static method?

• It compiles and runs normally
  

• Compile-time error

• Runtime exception

• It automatically converts to static

What is the output of the following?

public class Example {

    static int count = 0;

 

    Example() {

        count++;

    }

 

    public static void main(String[] args) {

        new Example();

        new Example();

        System.out.println(count);

    }

}

• 1

• 2

• 0

• error

Which of the following statements is true?

• A static method can access instance variables directly.
  

• A static method can be overridden.

• A static method belongs to the object, not the class.

• A static method cannot use this keyword.

  Which of the following can be marked static in Java?

• Variables
  

• Methods

• Blocks

• All of the above