JSON for human-readable data in IOT Protocols - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a JSON object with a device name.

IOT Protocols

{
  "device": "[1]"
}

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

Astatus

Bdevice_name

Csensor_01

Dtemperature

Attempts:

3 left

💡 Hint

Common Mistakes

Using a key name instead of a value.

Choosing a value that is not a device name.

The key "device" should have a value representing the device name, such as "sensor_01".

2fill in blank

medium

Complete the JSON to include the temperature reading as a number.

IOT Protocols

{
  "temperature": [1]
}

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

A"25C"

B"twenty five"

Ctemperature

D25

Attempts:

3 left

💡 Hint

Common Mistakes

Putting numbers inside quotes, making them strings.

Using words instead of numbers.

The temperature value should be a number without quotes to represent numeric data in JSON.

3fill in blank

hard

Fix the error in this JSON snippet by completing the missing value for the status key.

IOT Protocols

{
  "status": [1]
}

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

Atrue

B"true"

CTrue

Dyes

Attempts:

3 left

💡 Hint

Common Mistakes

Using capitalized True which is Python style, not JSON.

Putting boolean values inside quotes.

In JSON, boolean values are lowercase true or false without quotes. "true" in quotes is a string, which is incorrect here.

4fill in blank

hard

Fill both blanks to create a JSON object with sensor ID and its reading.

IOT Protocols

{
  "sensor_id": "[1]",
  "reading": [2]
}

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

Asensor_123

B45.6

C"45.6"

Dsensor

Attempts:

3 left

💡 Hint

Common Mistakes

Putting the reading value inside quotes.

Not quoting the sensor ID string.

The sensor ID should be a string, so it needs quotes. The reading is a number, so it should not have quotes.

5fill in blank

hard

Fill all three blanks to create a JSON object with device name, active status, and battery level.

IOT Protocols

{
  "device": "[1]",
  "active": [2],
  "battery": [3]
}

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

AsensorX

Btrue

C87

D"true"

Attempts:

3 left

💡 Hint

Common Mistakes

Using "true" as a string instead of boolean true.

Not quoting the device name string.

The device name is a string and needs quotes. The active status is a boolean true without quotes. The battery level is a number without quotes.

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