JSON for human-readable data in IOT Protocols - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this JSON parsing command?

Given the JSON string {"temperature": 22, "humidity": 45}, what will be the output of parsing it in a typical IoT device script?

IOT Protocols

json_string = '{"temperature": 22, "humidity": 45}'
import json
data = json.loads(json_string)
print(data['temperature'])

A 22

B "22"

C 45

D KeyError

💡 Hint

Remember that JSON numbers become numbers in Python after parsing.

The JSON string contains a number 22 for the key 'temperature'. Parsing converts it to an integer, so printing data['temperature'] outputs 22.

🧠 Conceptual

intermediate

Why is JSON preferred for human-readable data in IoT?

Which of the following reasons best explains why JSON is widely used for human-readable data exchange in IoT devices?

A JSON uses a simple text format that is easy for humans to read and write

B JSON is a binary format optimized for speed over readability

C JSON requires special software to be understood by humans

D JSON is only compatible with web browsers

💡 Hint

Think about the format's readability and simplicity.

JSON uses plain text with clear syntax, making it easy for humans to read and write, which is why it is popular in IoT data exchange.

❓ Troubleshoot

advanced

What error occurs with malformed JSON?

If an IoT device receives this JSON string: {"temp": 20, "humidity": 50 (missing closing brace), what error will the JSON parser raise?

A ValueError

B JSONDecodeError

C SyntaxError

D KeyError

💡 Hint

Consider the specific error type for JSON parsing issues.

The JSON parser raises JSONDecodeError when the JSON string is malformed, such as missing a closing brace.

🔀 Workflow

advanced

Order the steps to send JSON data from an IoT sensor

Arrange these steps in the correct order to send sensor data as JSON from an IoT device to a server:

A 1,3,2,4

B 2,1,3,4

C 1,2,3,4

D 3,1,2,4

💡 Hint

Think about the natural flow from data collection to sending and receiving.

First, the device reads sensor data, then converts it to JSON, sends it, and finally the server receives and parses it.

✅ Best Practice

expert

Which practice improves JSON readability for humans in IoT logs?

When logging JSON data from IoT devices for human review, which practice best improves readability?

A Minify JSON by removing all spaces and line breaks

B Use compact JSON with no indentation

C Convert JSON to binary format before logging

D Format JSON with indentation and line breaks

💡 Hint

Think about how indentation affects reading structured data.

Indentation and line breaks make JSON easier to read and understand for humans, especially in logs.

Practice

1. What is the main purpose of JSON in IoT protocols?

easy

A. To store data in a clear, easy-to-read text format

B. To encrypt data for security

C. To compress data for faster transmission

D. To execute commands on devices

Solution

1. Step 1: Understand JSON's role

   JSON is designed to store and share data in a readable text format.

2. Step 2: Compare options

   Only To store data in a clear, easy-to-read text format describes JSON's main purpose correctly; others describe different functions.

3. Final Answer:

   To store data in a clear, easy-to-read text format -> Option A

4. Quick Check:

   JSON = readable data format [OK]

Hint: Remember JSON is for readable data, not encryption or commands [OK]

Common Mistakes:

• Confusing JSON with encryption methods
• Thinking JSON compresses data
• Assuming JSON runs device commands

2. Which of the following is the correct JSON syntax for an object with a key "device" and value "sensor"?

easy

A. {'device': 'sensor'}

B. {device: "sensor"}

C. {"device": "sensor"}

D. ["device": "sensor"]

Solution

1. Step 1: Recall JSON syntax rules

   Keys and string values must be in double quotes, and objects use curly braces.

2. Step 2: Check each option

   {"device": "sensor"} uses double quotes correctly around key and value with curly braces; others have syntax errors.

3. Final Answer:

   {"device": "sensor"} -> Option C

4. Quick Check:

   JSON keys and strings use double quotes [OK]

Hint: Use double quotes for keys and strings in JSON [OK]

Common Mistakes:

• Using single quotes instead of double quotes
• Omitting quotes around keys
• Using square brackets for objects

3. Given the JSON data: {"temperature": 22, "humidity": 45}, what is the value of the key "humidity"?

medium

A. 22

B. 45

C. "humidity"

D. null

Solution

1. Step 1: Identify the key-value pairs

   The JSON object has keys "temperature" with value 22 and "humidity" with value 45.

2. Step 2: Find the value for "humidity"

   The value paired with "humidity" is 45.

3. Final Answer:

   45 -> Option B

4. Quick Check:

   humidity value = 45 [OK]

Hint: Look directly after the key for its value in JSON [OK]

Common Mistakes:

• Confusing key names with values
• Selecting the wrong number
• Assuming null if unsure

4. Identify the error in this JSON snippet: {"status": "active", "count": 10,}

medium

A. Trailing comma after last item

B. Missing quotes around keys

C. Using single quotes instead of double quotes

D. Keys and values are reversed

Solution

1. Step 1: Check JSON syntax rules

   JSON objects cannot have a comma after the last key-value pair.

2. Step 2: Locate the error in the snippet

   The comma after "count": 10 is invalid and causes a syntax error.

3. Final Answer:

   Trailing comma after last item -> Option A

4. Quick Check:

   No trailing commas allowed in JSON objects [OK]

Hint: No comma after last item in JSON objects [OK]

Common Mistakes:

• Leaving a comma after the last pair
• Using single quotes for strings
• Omitting quotes around keys

5. You want to send sensor data with temperature and humidity using JSON. Which JSON structure correctly represents temperature 25 and humidity 60?

hard

A. {"temperature"; 25, "humidity"; 60}

B. ["temperature": 25, "humidity": 60]

C. {"temperature": "25", "humidity": "60"}

D. {"temperature": 25, "humidity": 60}

Solution

1. Step 1: Understand JSON data types

   Numbers should be unquoted for numeric values; strings are quoted.

2. Step 2: Evaluate each option

   {"temperature": 25, "humidity": 60} uses correct syntax with numeric values unquoted and proper colons and commas.

3. Step 3: Check other options

   ["temperature": 25, "humidity": 60] uses brackets incorrectly; A uses semicolons instead of colons; D quotes numbers as strings.

4. Final Answer:

   {"temperature": 25, "humidity": 60} -> Option D

5. Quick Check:

   Numbers unquoted, colons separate keys and values [OK]

Hint: Use curly braces and colons; numbers unquoted in JSON [OK]

Common Mistakes:

• Using square brackets for objects
• Replacing colons with semicolons
• Quoting numeric values unnecessarily