Variable declaration syntax in Terraform - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a variable with a default value.

Terraform

variable "region" {
  type    = string
  default = [1]
}

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

A"us-west-2"

Bregion

Cus-west-2

Dstring

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to use quotes around string values.

Using a bare word without quotes for the default.

The default value for a Terraform variable must be a string literal enclosed in quotes.

2fill in blank

medium

Complete the code to declare a variable with a list type.

Terraform

variable "availability_zones" {
  type = [1]
}

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

Abool

Blist(string)

Cmap(string)

Dstring

Attempts:

3 left

💡 Hint

Common Mistakes

Using just 'string' instead of 'list(string)'.

Confusing map and list types.

To declare a variable as a list of strings in Terraform, use list(string) as the type.

3fill in blank

hard

Fix the error in the variable declaration for a boolean variable.

Terraform

variable "enable_logging" {
  type    = bool
  default = [1]
}

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

A"true"

BFalse

C"false"

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Putting quotes around boolean values.

Using capitalized boolean values like False.

Boolean default values in Terraform must be unquoted true or false, not strings.

4fill in blank

hard

Fill both blanks to declare a variable with a map of strings type and a default value.

Terraform

variable "tags" {
  type    = [1]
  default = [2]
}

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

Amap(string)

B{"Environment" = "dev", "Owner" = "team"}

C["dev", "team"]

Dlist(string)

Attempts:

3 left

💡 Hint

Common Mistakes

Using list type instead of map.

Using list syntax for default instead of map syntax.

The type for a map of strings is map(string). The default value must be a map with key-value pairs.

5fill in blank

hard

Fill all three blanks to declare a variable with a description, type, and default value.

Terraform

variable "instance_count" {
  description = [1]
  type        = [2]
  default     = [3]
}

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

A"Number of instances to create"

Bnumber

C3

D"3"

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around the default number value.

Using string type instead of number.

The description is a string in quotes. The type for numbers is number. The default value is a number without quotes.

Practice

1. What is the purpose of declaring a variable in Terraform?

easy

A. To write comments in the Terraform file

B. To create a new resource in the cloud

C. To define the output of a Terraform plan

D. To store values that can be reused and customized in the configuration

Solution

1. Step 1: Understand variable role in Terraform

   Variables hold values that can be changed without editing the main code, making it flexible.

2. Step 2: Compare with other options

   Creating resources, defining outputs, or comments are different Terraform features, not variable declaration.

3. Final Answer:

   To store values that can be reused and customized in the configuration -> Option D

4. Quick Check:

   Variables = reusable values [OK]

Hint: Variables hold reusable values to customize code easily [OK]

Common Mistakes:

• Confusing variables with resources
• Thinking variables define outputs
• Using variables as comments

2. Which of the following is the correct syntax to declare a string variable named region with a default value of us-west-1 in Terraform?

easy

A. variable region = "us-west-1"

B. var region = "us-west-1"

C. variable "region" { type = string default = "us-west-1" }

D. variable "region" { default = us-west-1 type = string }

Solution

1. Step 1: Recall Terraform variable declaration syntax

   Variables use the block format: variable "name" { type = TYPE default = VALUE } with quotes around strings.

2. Step 2: Check each option

   variable "region" { type = string default = "us-west-1" } matches correct syntax with proper quotes and order. Options B and C are invalid syntax. variable "region" { default = us-west-1 type = string } misses quotes around default value.

3. Final Answer:

   variable "region" { type = string default = "us-west-1" } -> Option C

4. Quick Check:

   Correct block syntax with quotes [OK]

Hint: Use variable block with quotes and type before default [OK]

Common Mistakes:

• Missing quotes around string values
• Using assignment (=) outside variable block
• Incorrect order or missing type keyword

3. Given this variable declaration in Terraform:

variable "instance_count" {
  type    = number
  default = 3
}

What will be the value of var.instance_count if no override is provided?

medium

A. 3

B. null

C. 0

D. Error: variable not set

Solution

1. Step 1: Identify default value in variable block

   The variable instance_count has a default value set to 3.

2. Step 2: Understand behavior when no override is given

   If no value is provided during plan or apply, Terraform uses the default value.

3. Final Answer:

   3 -> Option A

4. Quick Check:

   Default value used when no override = 3 [OK]

Hint: Default value applies if no input given [OK]

Common Mistakes:

• Assuming default is zero if not set
• Expecting error without override
• Confusing null with default

4. Identify the error in this Terraform variable declaration:

variable "enable_logging" {
  type = bool
  default = "true"
}

medium

A. The default value should not be in quotes for bool type

B. The type should be string, not bool

C. The variable name is invalid

D. Missing description field

Solution

1. Step 1: Check type and default value compatibility

   The variable type is bool, so the default must be a boolean value, not a string.

2. Step 2: Identify the error in default value

   The default is "true" (a string), but it should be true (boolean without quotes).

3. Final Answer:

   The default value should not be in quotes for bool type -> Option A

4. Quick Check:

   Boolean default must be unquoted true/false [OK]

Hint: Boolean defaults must be unquoted true or false [OK]

Common Mistakes:

• Putting boolean default in quotes
• Confusing string and bool types
• Ignoring type mismatch errors

5. You want to declare a variable tags in Terraform that holds a map of strings with a default value of {"env" = "prod", "team" = "devops"}. Which is the correct declaration?

hard

A. variable "tags" { type = map(string) default = { env = prod, team = devops } }

B. variable "tags" { type = map(string) default = { "env" = "prod", "team" = "devops" } }

C. variable "tags" { type = map default = { "env" = "prod", "team" = "devops" } }

D. variable "tags" { type = map(string) default = ["env" = "prod", "team" = "devops"] }

Solution

1. Step 1: Understand map type syntax in Terraform

   Maps of strings use type = map(string) and string values must be quoted.

2. Step 2: Check default value format

   Default must be a map with quoted string values inside curly braces, not square brackets.

3. Step 3: Evaluate options

   variable "tags" { type = map(string) default = { "env" = "prod", "team" = "devops" } } correctly uses type = map(string) and default with quoted values. variable "tags" { type = map(string) default = { env = prod, team = devops } } misses quotes on values, variable "tags" { type = map default = { "env" = "prod", "team" = "devops" } } misses string type, variable "tags" { type = map(string) default = ["env" = "prod", "team" = "devops"] } uses square brackets (list) incorrectly.

4. Final Answer:

   variable "tags" { type = map(string) default = { "env" = "prod", "team" = "devops" } } -> Option B

5. Quick Check:

   Map(string) with quoted string values in braces [OK]

Hint: Use map(string) type and quoted string values in braces [OK]

Common Mistakes:

• Missing quotes on map values
• Using map without specifying string type
• Using list syntax instead of map