Object and Classes I FiniteQuest

Objects and Classes I

Objects and Classes in Programming, Constructors, Encapsulation and Access Modifiers, Static Members, Inheritance and Polymorphism, Advanced Topics: Anonymous Objects and Inner Classes, Object Cloning, Real-world Object Representation, E-commerce System

1 / 10

Which of the following is true about objects in object-oriented programming?

An object is a blueprint for creating classes.

An object is an instance of a class.

Objects and classes are the same.

Objects cannot have methods.

2 / 10

What happens if you declare a class without any fields or methods?

It causes a compilation error.

The class cannot be instantiated.

The class is valid but does nothing.

The class is considered abstract.

3 / 10

What is the primary purpose of a constructor in a class?

To initialize an object when it is created.

To call other methods in the class.

To define the structure of the class.

To provide default values for fields.

4 / 10

Which statement about constructors is true?

A class can only have one constructor.

Constructors must always have a void return type.

Constructors have the same name as the class.

Constructors cannot have parameters.

5 / 10

What will happen if a class does not explicitly define a constructor?

The class cannot be instantiated.

A default constructor is provided by the compiler.

It results in a runtime error.

None of the above.

6 / 10

Which access modifier ensures that a field is accessible only within its class?

public

protected

private

default

7 / 10

Which of the following statements is true about encapsulation?

Encapsulation is achieved by using inheritance.

Encapsulation allows hiding of data implementation.

Encapsulation requires the use of abstract classes.

Encapsulation is not supported in Java.

8 / 10

What is the purpose of getter and setter methods in Java?

To directly access private fields.

To modify the visibility of fields.

To access and update private fields indirectly.

None of the above.

9 / 10

Which statement about static methods and variables is correct?

Static methods can only access non-static variables

Static variables are shared among all objects of a class.

Static methods cannot be called without creating an object.

Static variables cannot be updated.

10 / 10

What will the following code output?

public class Test {
static int count = 0;
public Test() {
count++;
}
public static void main(String[] args) {
Test obj1 = new Test();
Test obj2 = new Test();
System.out.println(Test.count);
}
}

Compilation Error

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