Factory Method pattern in LLD - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare the Factory Method in the Creator class.

LLD

abstract class Creator {
    abstract [1] createProduct();
}

Drag options to blanks, or click blank then click option'

Avoid

BProduct

Cint

DString

Attempts:

3 left

💡 Hint

Common Mistakes

Using void as return type which means no object is returned.

Using primitive types like int or String which are unrelated.

The Factory Method returns a Product type object, so the return type must be Product.

2fill in blank

medium

Complete the code to implement the Factory Method in the ConcreteCreator class.

LLD

class ConcreteCreator extends Creator {
    @Override
    public [1] createProduct() {
        return new ConcreteProduct();
    }
}

Drag options to blanks, or click blank then click option'

AConcreteProduct

Bvoid

CProduct

Dint

Attempts:

3 left

💡 Hint

Common Mistakes

Using ConcreteProduct as return type breaks abstraction.

Using void or primitive types causes compile errors.

The method must return the abstract type Product to follow the Factory Method pattern, even if it returns a ConcreteProduct instance.

3fill in blank

hard

Fix the error in the client code that uses the Factory Method to get a product.

LLD

Creator creator = new ConcreteCreator();
Product product = creator.[1]();
product.use();

Drag options to blanks, or click blank then click option'

AcreateProduct

BmakeProduct

CgetProduct

DnewProduct

Attempts:

3 left

💡 Hint

Common Mistakes

Using method names not declared in Creator causes compile errors.

Trying to instantiate product directly instead of using factory method.

The Factory Method is named createProduct in the Creator class, so the client must call this method.

4fill in blank

hard

Fill both blanks to complete the product interface and its concrete implementation.

LLD

interface [1] {
    void [2]();
}

class ConcreteProduct implements Product {
    public void use() {
        System.out.println("Using ConcreteProduct");
    }
}

Drag options to blanks, or click blank then click option'

AProduct

Buse

Cexecute

Drun

Attempts:

3 left

💡 Hint

Common Mistakes

Using different interface names breaks the pattern.

Method names that don't match cause implementation errors.

The interface is named Product and declares the method use() which the concrete class implements.

5fill in blank

hard

Fill all three blanks to complete the Creator class with a factory method and a business logic method.

LLD

abstract class Creator {
    public abstract [1] createProduct();

    public void [2]() {
        [3] product = createProduct();
        product.use();
    }
}

Drag options to blanks, or click blank then click option'

AProduct

Boperate

Dexecute

Attempts:

3 left

💡 Hint

Common Mistakes

Mismatching return and variable types causes errors.

Using incorrect method names breaks the pattern.

The factory method returns a Product. The business method is named operate and it calls createProduct() to get a product and use it.