JSON structure
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Which JSON snippet is valid?
2. Which brackets hold an ordered list of values in JSON?
3. Which JSON object stores a key-value pair correctly?
4. Which line stores a boolean and a null correctly?
5. How do you read the first item of this JSON array: ["red", "green", "blue"]?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1{"name": "Ava", "year": 12} | AThe number 88 and the boolean true are wrapped in quotes, so they are stored as strings rather than a number and a boolean | |
| 2["Maths", "English", "Science"] | BJSON keys and strings must use double quotes, not single quotes | |
| 3Numbers, booleans and null are written without quotes, while strings need double quotes | C{"age": 17, "active": true, "phone": null} | |
| 4Values can be nested: an object can hold an array, and an array can hold objects | D{"students": [{"name": "Zoe"}, {"name": "Leo"}]} | |
| 5{'name': 'Ava'} | EA JSON array: square brackets hold an ordered list of values separated by commas | |
| 6{"id": 1, "score": "88", "pass": "true"} | FA JSON object: curly braces hold key-value pairs, with double-quoted keys and strings, separated by commas |
C
Definitions
JSON object and array
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
{"name"_ "Ava", "year": 12}
2.
{"scores": _88, 74, 91]}
3.
{"age": 17, "isAdult": _____}
4.
{"name": "Zoe", "middleName": ____}
5.
{"pet": _"name": "Rex", "age": 3}}
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
{
B
"name": "Ava",
C
"age": 16,
D
"active": True
E
}
Question 2
A
[
B
"city": "Brisbane",
C
"temp": 28
D
}
Question 3
A
{
B
"id": 7,
C
"tags": ["a", "b"],
D
"note": nil
E
}
Question 4
A
{
B
"scores": (88, 74, 91),
C
"pass": true
D
}
Question 5
A
{
B
user: {
C
"name": "Liam"
D
}
E
}
Answer Key
JSON structure
Section A: Quick Questions
Q1
A — {"name": "Ava", "age": 17}
Q2
A — Square brackets [ ] make an array
Q3
B — {"city": "Brisbane"}
Q4
A — {"active": true, "nickname": null}
Q5
B — Items are ordered, so "red" is first
Section B: Match the Pairs
Q1
{"name": "Ava", "year": 12} → A JSON object: curly braces hold key-value pairs, with double-quoted keys and strings, separated by commas
Q2
["Maths", "English", "Science"] → A JSON array: square brackets hold an ordered list of values separated by commas
Q3
Numbers, booleans and null are written without quotes, while strings need double quotes → {"age": 17, "active": true, "phone": null}
Q4
Values can be nested: an object can hold an array, and an array can hold objects → {"students": [{"name": "Zoe"}, {"name": "Leo"}]}
Q5
{'name': 'Ava'} → JSON keys and strings must use double quotes, not single quotes
Q6
{"id": 1, "score": "88", "pass": "true"} → The number 88 and the boolean true are wrapped in quotes, so they are stored as strings rather than a number and a boolean
Section C: Definitions
Q1
JSON object and array — JSON stores data as key-value pairs inside {} objects and as ordered lists of values inside [] arrays. Keys are double-quoted strings. Values can be nested.Section D: Fill in the Blanks
Q1
{"name": "Ava", "year": 12}Q2
{"scores": [88, 74, 91]}Q3
{"age": 17, "isAdult": false}Q4
{"name": "Zoe", "middleName": null}Q5
{"pet": {"name": "Rex", "age": 3}}Section E: Spot the Error
Q1
D — JSON booleans must be lowercase. It should be "active": true. Capital-T True is Python, not JSON.
Q2
A — A JSON object of key-value pairs must open with a curly brace {, not a square bracket. It closes with }, so the brackets don't match.
Q3
D — JSON's empty value is null, not nil. The line should be "note": null.
Q4
B — JSON arrays use square brackets, not round brackets. It should be "scores": [88, 74, 91],.
Q5
B — Every JSON key must be a double-quoted string, even for a nested object. It should be "user": {.