Why hands-on MQTT implementation matters in IOT Protocols - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to connect an MQTT client to a broker.

IOT Protocols

client.connect('[1]')

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

Amqtt.example.com

Blocalhost

C192.168.1.1

Dbroker.hivemq.com

Attempts:

3 left

💡 Hint

Common Mistakes

Using an IP address that is not reachable

Leaving the broker address empty

Using localhost when the broker is remote

The code connects the MQTT client to the public broker at broker.hivemq.com.

2fill in blank

medium

Complete the code to subscribe to the topic 'home/temperature'.

IOT Protocols

client.subscribe('[1]')

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

Ahome/temperature

Bhome/pressure

Coffice/temperature

Dhome/humidity

Attempts:

3 left

💡 Hint

Common Mistakes

Subscribing to the wrong topic

Using a topic with a typo

Using a topic from a different location

Subscribing to 'home/temperature' allows the client to receive messages published to that topic.

3fill in blank

hard

Fix the error in publishing a message to 'home/light'.

IOT Protocols

client.publish('[1]', 'ON')

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

Ahome_light

Bhome/light

Chome/light/status

Dhome.light

Attempts:

3 left

💡 Hint

Common Mistakes

Using underscores instead of slashes

Using dots instead of slashes

Adding extra topic levels unintentionally

The correct topic format uses slashes, so 'home/light' is valid. Other options use different separators or wrong topic names.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps topics to their message lengths.

IOT Protocols

{topic: len([1]) for topic, [2] in messages.items()}

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

Amessage

Bmsg

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names for both blanks

Using a variable not defined in the loop

Confusing topic and message variables

The comprehension iterates over messages.items() with variables topic and msg. The length is calculated on msg.

5fill in blank

hard

Fill all three blanks to filter messages with payload length greater than 5 and create a new dictionary with uppercase topics.

IOT Protocols

{topic.upper(): [1] for topic, [2] in messages.items() if len([3]) > 5}

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

Apayload

Bmsg

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing variable names between blanks

Using topic instead of message for length check

Not converting topic to uppercase

The comprehension uses 'msg' as the dictionary value, 'msg' as the loop variable for message, and filters by length of 'msg'.