Schema definitions in Rest API - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a simple JSON schema with a required string property called 'name'.

Rest API

{
  "type": "object",
  "properties": {
    "name": { "type": "[1]" }
  },
  "required": ["name"]
}

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

Ainteger

Barray

Cboolean

Dstring

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'integer' or 'boolean' instead of 'string' for text properties.

The property 'name' should be of type string in the JSON schema.

2fill in blank

medium

Complete the code to add an optional integer property called 'age' to the schema.

Rest API

{
  "type": "object",
  "properties": {
    "age": { "type": "[1]" }
  }
}

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

Anull

Binteger

Cboolean

Dstring

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'string' type for numeric properties.

The 'age' property should be an integer type in the JSON schema.

3fill in blank

hard

Fix the error in the schema by completing the type for the 'emails' property which should be an array of strings.

Rest API

{
  "type": "object",
  "properties": {
    "emails": {
      "type": "[1]",
      "items": { "type": "string" }
    }
  }
}

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

Aboolean

Bobject

Carray

Dstring

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'object' or 'string' instead of 'array' for list properties.

The 'emails' property should be an array type containing strings.

4fill in blank

hard

Fill in the blank to define a property 'status' that can only be one of the specified string values.

Rest API

{
  "type": "object",
  "properties": {
    "status": {
      "type": "[1]",
      "enum": ["active", "inactive", "pending"]
    }
  }
}

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

Astring

Binteger

Carray

Dboolean

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'array' or 'integer' type for enum string values.

The 'status' property should be a string type with specific allowed values.

5fill in blank

hard

Fill all three blanks to define a schema with a required 'id' (integer), optional 'tags' (array of strings), and a 'published' boolean.

Rest API

{
  "type": "object",
  "properties": {
    "id": { "type": "[1]" },
    "tags": {
      "type": "[2]",
      "items": { "type": "string" }
    },
    "published": { "type": "[3]" }
  },
  "required": ["id"]
}

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

Ainteger

Barray

Cboolean

Dstring

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing types like using 'string' for id or 'integer' for published.

The 'id' is an integer, 'tags' is an array of strings, and 'published' is a boolean.

Practice

1. What is the main purpose of a schema definition in a REST API?

easy

A. To improve the speed of the API response

B. To store user login information securely

C. To handle server errors automatically

D. To describe the structure and rules of the data exchanged

Solution

1. Step 1: Understand what schema definitions do

   Schema definitions specify how data should look and what rules it must follow in an API.

2. Step 2: Match purpose with options

   Only To describe the structure and rules of the data exchanged correctly states that schemas describe data structure and rules.

3. Final Answer:

   To describe the structure and rules of the data exchanged -> Option D

4. Quick Check:

   Schema = Data structure and rules [OK]

Hint: Schemas define data shape and rules in APIs [OK]

Common Mistakes:

• Confusing schema with security features
• Thinking schema speeds up API
• Assuming schema handles errors

2. Which of the following is the correct way to define a simple string property called name in an OpenAPI schema?

easy

A. name: string

B. name: { type: 'string' }

C. name: 'string' type

D. name: { string: true }

Solution

1. Step 1: Recall OpenAPI property syntax

   Properties are defined as key-value pairs with a type inside an object, e.g., name: { type: 'string' }.

2. Step 2: Compare options

   Only name: { type: 'string' } matches the correct syntax for defining a string property.

3. Final Answer:

   name: { type: 'string' } -> Option B

4. Quick Check:

   Property syntax = key: { type: 'string' } [OK]

Hint: Use key: { type: 'string' } for string properties [OK]

Common Mistakes:

• Writing type outside an object
• Using plain string without type key
• Confusing property name with type

3. Given this OpenAPI schema snippet, what is the type of the age property?

components:
  schemas:
    User:
      type: object
      properties:
        age:
          type: integer
          minimum: 0

medium

A. integer

B. string

C. boolean

D. array

Solution

1. Step 1: Read the schema property definition

   The age property is defined with type: integer and a minimum value of 0.

2. Step 2: Identify the data type

   The type clearly states integer, meaning whole numbers only.

3. Final Answer:

   integer -> Option A

4. Quick Check:

   age type = integer [OK]

Hint: Look for 'type' key to find property data type [OK]

Common Mistakes:

• Assuming age is string by default
• Confusing integer with boolean
• Ignoring the type key

4. Identify the error in this JSON schema snippet for a REST API:

{
  "type": "object",
  "properties": {
    "id": { "type": "integer" },
    "email": { "type": "string", "format": "email" },
    "active": "boolean"
  },
  "required": ["id", "email"]
}

medium

A. "id" property type should be string

B. "required" must include "active"

C. "active" property should be an object with a type key

D. Missing comma after "email" property

Solution

1. Step 1: Check property definitions

   Each property must be an object with a "type" key. "active" is given as a string "boolean" instead of an object.

2. Step 2: Validate other parts

   "id" type integer is correct, "required" does not need "active", and commas are correctly placed.

3. Final Answer:

   "active" property should be an object with a type key -> Option C

4. Quick Check:

   Property format = object with type key [OK]

Hint: Properties must be objects with type keys, not strings [OK]

Common Mistakes:

• Writing property types as strings directly
• Forgetting to wrap property details in objects
• Assuming required means all properties

5. You want to define a schema for a REST API response that returns a list of users, where each user has a username (string) and roles (array of strings). Which schema snippet correctly represents this?

hard

A. type: object
properties:
users:
type: array
items:
type: object
properties:
username:
type: string
roles:
type: array
items:
type: string

B. type: array
items:
type: object
properties:
username: string
roles: array of strings

C. type: object
properties:
users:
type: object
properties:
username: string
roles: string

D. type: array
items:
type: string
properties:
username: string
roles: array

Solution

1. Step 1: Understand the data structure

   The response is an object with a "users" property that is an array of user objects.

2. Step 2: Check each user object schema

   Each user has "username" as string and "roles" as an array of strings, so nested arrays and objects are needed.

3. Step 3: Match with options

   Only type: object properties: users: type: array items: type: object properties: username: type: string roles: type: array items: type: string correctly nests arrays and objects with proper types and keys.

4. Final Answer:

   type: object properties: users: type: array items: type: object properties: username: type: string roles: type: array items: type: string -> Option A

5. Quick Check:

   Nested arrays and objects = type: object properties: users: type: array items: type: object properties: username: type: string roles: type: array items: type: string [OK]

Hint: Use nested objects and arrays for complex data shapes [OK]

Common Mistakes:

• Writing array items as plain strings
• Confusing object and array types
• Missing nested items key for arrays