Dependency injection framework in LLD - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a dependency injection container.

LLD

container = [1]()

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AServiceLocator

BDIContainer

CInjector

DProvider

Attempts:

3 left

💡 Hint

Common Mistakes

Using ServiceLocator instead of DIContainer

Confusing Injector with container

The DIContainer is the standard class to create a dependency injection container.

2fill in blank

medium

Complete the code to register a service class in the container.

LLD

container.[1](MyService)

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Aadd

Bprovide

Cbind

Dsingleton

Attempts:

3 left

💡 Hint

Common Mistakes

Using bind which may create new instances

Using add which is not a standard method

The singleton method registers a service as a single shared instance.

3fill in blank

hard

Fix the error in the code to retrieve a service instance from the container.

LLD

service = container.[1](MyService)

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Aresolve

BgetInstance

Cfetch

Dcreate

Attempts:

3 left

💡 Hint

Common Mistakes

Using getInstance which is not standard here

Using create which may instantiate new objects incorrectly

The resolve method is used to get the instance of a registered service.

4fill in blank

hard

Fill both blanks to define a service with constructor injection.

LLD

class MyController:
    def __init__(self, [1]):
        self.service = [2]

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Aservice

Bself.service

CMyService()

Dservice()

Attempts:

3 left

💡 Hint

Common Mistakes

Calling service as a function

Assigning MyService() directly inside constructor

The constructor takes service as parameter and assigns it to self.service for use in the class.

5fill in blank

hard

Fill all three blanks to register and resolve a service with dependencies.

LLD

container.[1](MyRepository)
container.[2](MyService, lambda: MyService([3]))

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Aregister

Bsingleton

Ccontainer.resolve(MyRepository)

Dprovide

Attempts:

3 left

💡 Hint

Common Mistakes

Using provide instead of register

Not resolving dependency inside lambda

First, register the repository. Then, register singleton service with a factory lambda that calls container.resolve(MyRepository) to inject the dependency.