Object type definition in Terraform - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define an object type with a string attribute named 'name'.

Terraform

variable "user" {
  type = object({
    name = [1]
  })
}

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

Astring

Bnumber

Cbool

Dlist

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'number' or 'bool' instead of 'string' for text attributes.

The attribute 'name' should be of type string in the object definition.

2fill in blank

medium

Complete the code to add an integer attribute 'age' to the object type.

Terraform

variable "person" {
  type = object({
    name = string,
    age  = [1]
  })
}

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

Anumber

Bstring

Cbool

Dlist

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'string' type for numeric attributes.

The 'age' attribute should be a number type to represent integers.

3fill in blank

hard

Fix the error in the object type definition by completing the missing type for 'active'.

Terraform

variable "account" {
  type = object({
    username = string,
    active   = [1]
  })
}

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

Alist

Bnumber

Cstring

Dbool

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'string' or 'number' instead of 'bool' for boolean attributes.

The 'active' attribute should be a bool type to represent true or false.

4fill in blank

hard

Fill both blanks to define an object with a string 'id' and a list of strings 'tags'.

Terraform

variable "resource" {
  type = object({
    id   = [1],
    tags = [2]
  })
}

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

Astring

Blist(string)

Cbool

Dnumber

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'list' without specifying the element type.

Using 'string' for the 'tags' list.

The 'id' is a string and 'tags' is a list of strings represented as list(string).

5fill in blank

hard

Fill all three blanks to define an object with 'name' (string), 'count' (number), and 'enabled' (bool).

Terraform

variable "config" {
  type = object({
    name    = [1],
    count   = [2],
    enabled = [3]
  })
}

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

Abool

Bnumber

Cstring

Dlist

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up types between attributes.

Using 'list' instead of primitive types.

The 'name' is a string, 'count' is a number, and 'enabled' is a bool.

Practice

1. What is the main purpose of defining an object type in Terraform?

easy

A. To group related values with specific names and types

B. To create a list of strings

C. To define a single integer value

D. To write shell scripts inside Terraform

Solution

1. Step 1: Understand object type concept

   An object type groups multiple related values, each with a name and a type.

2. Step 2: Compare with other types

   Unlike lists or single values, objects organize structured data clearly.

3. Final Answer:

   To group related values with specific names and types -> Option A

4. Quick Check:

   Object type = group related named values [OK]

Hint: Objects group named values, not single or list values [OK]

Common Mistakes:

• Confusing object with list or map types
• Thinking object holds only one value
• Assuming object is for scripting

2. Which of the following is the correct syntax to define an object type with a string field name and a number field age in Terraform?

easy

A. object({ name string, age number })

B. object({ name: string, age: number })

C. object({ "name" = string, "age" = number })

D. object({ name = string, age = number })

Solution

1. Step 1: Recall object type syntax

   Terraform object types use curly braces with unquoted identifier keys and equal signs: object({ key = type, ... })

2. Step 2: Check each option

   object({ name = string, age = number }) correctly uses unquoted keys and equal signs. Others use invalid syntax like colons, quoted keys for simple identifiers, or missing equals.

3. Final Answer:

   object({ name = string, age = number }) -> Option D

4. Quick Check:

   Object keys unquoted with = sign [OK]

Hint: Object keys use unquoted identifiers with = type [OK]

Common Mistakes:

• Using colons instead of equal signs
• Quoting keys in object type
• Omitting commas or using wrong separators

3. Given this variable definition in Terraform:

variable "person" {
  type = object({
    name = string
    age  = number
  })
  default = {
    name = "Alice"
    age  = 30
  }
}

What will be the value of var.person.age?

medium

A. "30"

B. 30

C. null

D. Error: type mismatch

Solution

1. Step 1: Analyze variable type and default

   The variable is an object with fields name (string) and age (number). Default sets age to 30 (number).

2. Step 2: Determine var.person.age value

   Accessing var.person.age returns the number 30 as defined.

3. Final Answer:

   30 -> Option B

4. Quick Check:

   Object field age = 30 number [OK]

Hint: Object fields keep their defined types and values [OK]

Common Mistakes:

• Thinking number becomes string automatically
• Expecting null if not accessed
• Confusing default with no value

4. Identify the error in this Terraform object type definition:

variable "config" {
  type = object({
    "enabled" = bool
    "count" = int
  })
  default = {
    enabled = true
    count = 3
  }
}

medium

A. The type int is invalid; should be number

B. Keys in object type should not be quoted

C. Default values must be strings

D. Boolean values cannot be used in objects

Solution

1. Step 1: Check type names in object

   Terraform uses number for numeric types, not int.

2. Step 2: Validate other syntax

   Quoted keys are allowed, default values match types, booleans are valid.

3. Final Answer:

   The type int is invalid; should be number -> Option A

4. Quick Check:

   Use number, not int, for numeric types [OK]

Hint: Use 'number' type, not 'int' in Terraform objects [OK]

Common Mistakes:

• Using 'int' instead of 'number'
• Thinking keys cannot be quoted
• Believing booleans are invalid in objects

5. You want to define a Terraform variable that accepts an object with a name (string), tags (map of strings), and an optional count (number). Which is the correct way to define this object type?

hard

A. object({ name = string, tags = map(string), count = number })

B. object({ "name" = string, "tags" = map(string), "count" = optional(number) })

C. object({ name = string, tags = map(string), count = optional(number) })

D. object({ name = string, tags = map(string), count = optional number })

Solution

1. Step 1: Recall optional attribute syntax

   Terraform uses optional(type) without quotes for optional fields inside object types.

2. Step 2: Check key quoting rules

   Keys in object type definitions use unquoted identifiers for standard names; quoting simple keys is incorrect.

3. Step 3: Evaluate options

   object({ name = string, tags = map(string), count = optional(number) }) correctly uses unquoted keys and optional(number) syntax. object({ "name" = string, "tags" = map(string), "count" = optional(number) }) quotes keys incorrectly. object({ name = string, tags = map(string), count = number }) misses optional. object({ name = string, tags = map(string), count = optional number }) has invalid syntax.

4. Final Answer:

   object({ name = string, tags = map(string), count = optional(number) }) -> Option C

5. Quick Check:

   Optional fields use optional(type) with unquoted keys [OK]

Hint: Use optional(type) without quotes and unquoted keys [OK]

Common Mistakes:

• Quoting keys in object type
• Missing optional() for optional fields
• Using invalid syntax like 'optional number'