Terraform-Associate-004 HashiCorp Certified: Terraform Associate (004) (HCTA0-004) Questions and Answers

Rationale for Correct Answer (True):

Variables without defaults are required inputs. If the calling module doesn’t supply a value, Terraform will fail with an error at plan time.

Analysis of Incorrect Option:

False: Incorrect, because Terraform does not assume defaults when none are provided.

Key Concept:

Terraform modules enforce required vs. optional variables depending on whether a default is set.

The purpose of state in Terraform is to keep track of the real-world resources managed by Terraform, mapping them to the configuration. The state file contains metadata about these resources, such as resource IDs and other important attributes, which Terraform uses to plan and manage infrastructure changes. The state enables Terraform to know what resources are managed by which configurations and helps in maintaining the desired state of the infrastructure.References = This role of state in Terraform is outlined in Terraform's official documentation, emphasizing its function in mapping configuration to real-world resources and storing vital metadata .

You should use the force-unlock command when automatic unlocking failed. Terraform will lock your state for all operations that could write state, such as plan, apply, or destroy. This prevents others from acquiring the lock and potentially corrupting your state. State locking happens automatically on all operations that could write state and you won’t see any message that it is happening. If state locking fails, Terraform will not continue. You can disable state locking for most commands with the -lock flag but it is not recommended. If acquiring the lock is taking longer than expected, Terraform will output a status message. If Terraform doesn’t output a message, state locking is still occurring if your backend supports it. Terraform has a force-unlock command to manually unlock the state if unlocking failed. Be very careful with this command. If you unlock the state when someone else is holding the lock it could cause multiple writers. Force unlock should only be used to unlock your own lock in the situation where automatic unlocking failed. To protect you, the force-unlock command requires a unique lock ID. Terraform will output this lock ID if unlocking fails. This lock ID acts as a nonce, ensuring that locks and unlocks target the correct lock. The other situations are not valid reasons to use the force-unlock command. You should not use the force-unlock command if you have a high priority change, if apply failed due to a state lock, or if you see a status message that you cannot acquire the lock. These situations indicate that someone else is holding the lock and you should wait for them to finish theiroperation or contact them to resolve the issue. Using the force-unlock command in these cases could result in data loss or inconsistency. References = [State Locking], [Command: force-unlock]

Changes invoked by terraform apply take effect once the resource provider has fulfilled the request, not after Terraform has updated the state file or immediately. The state file is only a reflection of the real resources, not a source of truth.

Rationale for Correct Answer (True):

A cloud block in Terraform configuration specifies a single Terraform Cloud or HCP Terraform workspace. You cannot use one cloud block for multiple workspaces.

Analysis of Incorrect Option:

False: Incorrect because a cloud block is a one-to-one mapping with a single workspace.

Key Concept:

Cloud blocks manage remote operations and backend configuration tied to one workspace.

Referencing Terraform Built-in Functions:

✅chomp: removes trailing newlines

✅join: combines list into string

✅split: splits string into list

❌slice:is nota valid Terraform string function (it's used in other languages like Python)

You do not need to use different Terraform commands depending on the cloud provider you use. Terraform commands are consistent across different providers, as they operate on the Terraform configuration files and state files, not on the provider APIs directly.

This command will upgrade the plugins to the latest acceptable version within the version constraints specified in the configuration. The other commands do not have an -upgrade option.

 To tell Terraform to stop managing a specific resource without destroying it, you can use the terraform state rm command. This command will remove the resource from the Terraform state, which means that Terraform will no longer track or update the corresponding remote object. However, the object will still exist in the remote system and you can later use terraform import to start managing it again in a different configuration or workspace. The syntax for this command is terraform state rm

Terraform can call modules from various sources including the public Terraform Registry, private registries, local file paths, or version control systems like GitHub.

Terraformdownloads modules and providersinto the .terraform directory inside the working directory.

A (/tmp/)– Incorrect; modules arenot stored temporarily.

C (In memory)– Incorrect; modules persist on disk.

D (Not cached)– Incorrect; Terraformdoes cache modulesfor efficiency.

Official Terraform Documentation Reference:

Terraform Module Caching

While terraform destroy is a common way to remove infrastructure, it isnot the only way.

You can also remove resources bydeleting them from the configuration and running terraform apply.

Manually deleting resources in the cloud provider can also remove infrastructure (but Terraform won’t be aware unless the state is updated).

Official Terraform Documentation Reference:

terraform destroy - HashiCorp Documentation

State locking prevents other users from modifying the state file while a Terraform operation is in progress. This prevents conflicts and data loss1.

Rationale for Correct Answer (C):

Best practice is to avoid hardcoding sensitive credentials in Terraform configurations or storing them in version control. Instead, credentials should be managed via environment variables, CLI authentication helpers, or secret managers (e.g., Vault).

Analysis of Incorrect Options:

A. Shared server: Not secure, introduces single point of failure and risk.

B. Storing credentials in config files: A major security risk, especially if pushed to version control.

D. None of the above: Incorrect, because option C is a valid and recommended approach.

Key Concept:

Security best practices in Terraform dictate that credentials should be externalized from Terraform code.

Destroy Command Options: Theterraform destroycommand is the correct method to destroy resources, and it requires either manual approval or the -auto-approve flag.

Unsupported Triggering Method: The--destroy flagis not a recognized option for plan or apply commands, making B the correct answer as it isnota valid way to initiate resource destruction.

For more on destroying resources, refer to theterraform destroy command documentationin the Terraform CLI reference.

None of the above methods prevent credentials from being stored in the state file. Terraform stores the provider configuration in the state file, which may include sensitive information such as credentials. This is a potential security risk and should be avoided if possible. To prevent credentials from being stored in the state file, you can use one of the following methods:

Use environment variables to pass credentials to the provider. This way, the credentials are not part of the provider configuration and are not stored in the state file. However, this method may not work for some providers that require credentials to be set in the provider block.

Use dynamic credentials to authenticate with your cloud provider. This way, Terraform Cloud or Enterprise will request temporary credentials from your cloud provider for each run and use them to provision your resources. The credentials are not stored in the state file and are revoked after the run is completed. This method is supported for AWS, Google Cloud Platform, Azure, and Vault. References = : [Sensitive Values in State] : Authenticate providers with dynamic credentials

Importing Existing Resources: Theterraform importcommand brings resources already deployed in a cloud environment into Terraform’s state file, allowing Terraform to manage them.

Workflow Usage: Importing is vital when managing resources created outside of Terraform or those in place before Terraform adoption.

Refer to Terraform’s import command documentation.

Terraform variable names are not saved in the state file, only their values are. The state file only stores the attributes of the resources and data sources that are managed by Terraform, not the variables that are used to configure them.

Terraform Cloud provides features like remote state storage and a web-based user interface for managing your Terraform runs. While it offers robust infrastructure as code capabilities, automatic backups of configuration and state are not directly provided by Terraform Cloud; instead, the state is stored remotely and secured.

Rationale for Correct Answer (C):

Version constraints must be specified with = and quotes, e.g.:

version = ">= 3.1"

This ensures compatibility with Terraform’s syntax.

Analysis of Incorrect Options:

A, B: Incorrect syntax, missing quotes or wrong operator format.

C: Correct Terraform syntax.

Key Concept:

Correct syntax in provider version constraints ensures reproducibility.

Terraform can manage resource dependencies implicitly or explicitly. Implicit dependencies are created when a resource references another resource or data source in its arguments. Terraform can infer the dependency from the reference and create or destroy the resources in the correct order. Explicit dependencies are created when you use the depends_on argument to specify that a resource depends on another resource or module. This is useful when Terraform cannot infer the dependency from the configuration or when you need to create a dependency for some reason outside of Terraform’s scope. References = : Create resource dependencies : Terraform Resource Dependencies Explained

Module variable assignments are not inherited from the parent module and you need to explicitly set them using the source argument. This allows you to customize the behavior of each module instance.

The -replace flag is used with the terraform apply command when there is a need to explicitly force Terraform to destroy and then recreate a specific resource during the next apply. This can be necessary in situations where a simple update is insufficient or when a resource must be re-provisioned to pick up certain changes.

Automated Visualization: HCP Terraform providesvisualization toolsthat map infrastructure configurations, helping users manage complex architectures.

Remote State Storage: Terraform Cloud offersremote state management, essential for teams working collaboratively on shared infrastructure, ensuring consistency and avoiding state conflicts.

For more information, consultTerraform Cloud and HCP Terraform featuresin the official documentation.

The terraform taint command marks a resource as tainted, which means it will be destroyed and recreated on the next apply. This way, you can replace the VM instance without affecting the database or other resources. References = [Terraform Taint]

Not all standard backend types support state locking and remote operations like plan, apply, and destroy. For example, the local backend does not support remote operations and state locking. State locking is a feature that ensures that no two users can make changes to the state file at the same time, which is crucial for preventing race conditions. Remote operations allow running Terraform commands on a remote server, which is supported by some backends like remote or consul, but not all.

Terraform creates the .terraform.lock.hcl file after the first terraform init command. This lock file ensures that the dependencies for your project are consistent across different runs by locking the versions of the providers and modules used.

The terraform state list command lists all resources that are managed by Terraform in the current state file1. The terraform state show command shows the attributes of a single resource in the state file2. By using these two commands, you can compare the VM IDs in your list with the ones in the state file and identify which one is managed by Terraform.

 If you manually destroy infrastructure, Terraform will automatically detect the change and update the state file during the next plan or apply. Terraform compares the current state of the infrastructure with the desired state in the configuration and generates a plan to reconcile the differences. If a resource is missing from the infrastructure but still exists in the state file, Terraform will attempt to recreate it. If a resource is present in the infrastructure but not in the state file, Terraform will ignore it unless you use the terraform import command to bring it under Terraform’s management. References = [Terraform State]

terraform initdoes not create a main.tf file.

Itinitializesthe Terraform working directory, downloads provider plugins, and configures the backend.

Terraform does not generate an example configuration (main.tf); users must create it manually.

Official Terraform Documentation Reference:

terraform init - HashiCorp Documentation

Module version is optional to reference a module on the Terraform Module Registry. If you omit the version constraint, Terraform will automatically use the latest available version of the module

terraform graphgeneratesGraphviz DOT formatoutput, which allows visualization ofresource dependenciesin Terraform.

A (terraform refresh)– Incorrect, as it only updates the state file.

C (terraform output)– Incorrect, as it only displays Terraform output values.

D (terraform show)– Incorrect, as it only displays the Terraform state.

Official Terraform Documentation Reference:

terraform graph - HashiCorp Documentation

Rationale for Correct Answer (A):

data blocks fetch information from providers (like AMI IDs, network info) that can be used in other resources.

Analysis of Incorrect Options:

B. local: Stores values, doesn’t fetch external data.

C. resource: Defines managed infrastructure, not read-only data.

D. provider: Configures connection to APIs, not data fetching.

Key Concept:

Data sources are read-only queries into existing infrastructure.

All of the statements are true of Terraform providers. Terraform providers are plugins that enable Terraform to interact with various APIs and services1. Anyone can write a Terraform provider, either as an individual or as part of a community2. HashiCorp maintains some providers, such as the AWS, Azure, and Google Cloud providers3. Cloud providers and infrastructure vendors can also write, maintain, or collaborate on Terraform providers, such as the VMware, Oracle, and Alibaba Cloud providers. References =

•1: Providers - Configuration Language | Terraform | HashiCorp Developer

•2: Plugin Development - How Terraform Works With Plugins | Terraform | HashiCorp Developer

•3: Terraform Registry

•: Terraform Registry

The Terraform collection type that should be used to store key/value pairs is map. A map is a collection of values that are accessed by arbitrary labels, called keys. The keys and values can be of any type, but the keys must be unique within a map. For example, var = { key1 = "value1", key2 = "value2" } is a map with two key/value pairs. Maps are useful for grouping related values together, such as configuration options or metadata. References = [Collection Types], [Map Type Constraints]

Speculative Plans: Terraform Cloud’sspeculative planfeature runs automatically when changes are detected in a linked VCS repository, enabling users to review potential infrastructure changes without committing them.

Automatic Integration: This feature automates the planning process by triggering when changes are committed, aiding teams in previewing infrastructure changes seamlessly.

For further understanding, see theTerraform Cloud VCS Integrationdocumentation.

Rationale for Correct Answer:When using count, Terraform creates resources indexed starting at 0.With count = 2, the instances are indexed as:

First instance → aws_instance.web[0]

Second instance → aws_instance.web[1]

To reference the name attribute of the second instance, the correct syntax is:

aws_instance.web[1].name

Analysis of Incorrect Options (Distractors):

A. [2]: Incorrect because indexing starts at 0 and only indices 0 and 1 exist.

B. *.name: Returns a list of all names, not a single instance value.

D. [1]: References the whole resource object, not the name attribute.

E. element(...): Incorrect syntax and wrong index; also unnecessary when direct indexing is available.

Key Concept:Understanding resource indexing with count and zero-based indexing in Terraform.

Terraformis written in Go, but it isdistributed as a standalone binaryanddoes notrequire the Go runtime.

Users do not need to install Go to run Terraform.

Official Terraform Documentation Reference:

Terraform Install Guide

The terraform apply command changes both the cloud infrastructure and the state file after you approve the execution plan. The command creates, updates, or destroys the infrastructure resources to match theconfiguration. It also updates the state file to reflect the new state of the infrastructure. The .terraform directory, the execution plan, and the Terraform code are not changed by the terraform apply command. References = Command: apply and Purpose of Terraform State

The Terraform Cloud private registry provides the ability to restrict modules to members of Terraform Cloud or Enterprise organizations. This allows you to share modules within your organization without exposing them to the public. The private registry also supports importing modules from your private VCS repositories. The public Terraform Module Registry, on the other hand, publishes modules from public Git repositories and makes them available to any user of Terraform. References = : Private Registry - Terraform Cloud : Terraform Registry - Provider Documentation

This is the command that lets you experiment with Terraform expressions, by providing an interactive console that allows you to evaluate expressions and see their results. You can use this command to test your expressions before using them in your configuration files.

Infrastructure as Code (IaC) can indeed be stored in a version control system along with application code. This practice is a fundamental principle of modern infrastructure management, allowing teams to apply software development practices like versioning, peer review, and CI/CD to infrastructure management. Storing IaC configurations in version control facilitates collaboration, history tracking, and change management.References = While this concept is a foundational aspect of IaC and is widely accepted in the industry, direct references from the HashiCorp Terraform Associate (003) study materials were not found in the provided files. However, this practice is encouraged in Terraform's best practices and various HashiCorp learning resources.

This is where the Terraform local backend stores its state, by default, unless you specify a different file name or location in your configuration. The local backend is the simplest backend type that stores the state file on your local disk.

The Terraform Registry allows any user to publish and share modules. Published modules support versioning, automatically generate documentation, allow browsing version histories, show examples and READMEs, and more. Public modules are managed via Git and GitHub, and publishing a module takes only a few minutes. Once a module is published, releasing a new version of a module is as simple as pushing a properly formed Git tag1.

References = The information can be verified from the Terraform Registry documentation on Publishing Modules provided by HashiCorp Developer1.

The terraform state file is locked when a Terraform operation that could write state is in progress. This prevents concurrent state operations that could corrupt the state. The forbidden actions when the state file is locked are those that could write state, such as terraform apply, terraform destroy, terraform refresh, terraform taint, terraform untaint, terraform import, and terraform state *. The terraform validate command is also forbidden, because it requires an initialized working directory with the state file. The allowed actions when the state file is locked are those that only read state, such as terraform plan, terraform show, terraform output, and terraform console. References = [State Locking] and [Command: validate]

The required_providers block is used to specify the provider versions that the configuration can work with. The version argument accepts a version constraint string, which must be enclosed in double quotes. The version constraint string can use operators such as >=, ~>, =, etc. to specify the minimum, maximum, or exact version of the provider. For example, version = ">= 3.1" means that theconfiguration can work with any provider version that is 3.1 or higher. References = [Provider Requirements] and [Version Constraints]

Rationale for Correct Answer (B):

Terraform uses a state file to map real-world resources to your configuration. By default, if no backend is explicitly defined, Terraform stores this information in a file named terraform.tfstate located in the same directory as your configuration files. This local state file is critical for Terraform to understand what infrastructure already exists and to plan updates correctly.

Analysis of Incorrect Options (Distractors):

A. .terraform.d (home directory subdirectory):

This is used for storing plugins and some global settings, not for resource state.

C. .terraform.lock.hcl (lock file):

This file locks provider versions to ensure reproducible runs, but it does not contain resource state information.

D. .terraform (subdirectory):

This folder contains cached provider binaries and related data, but not the actual state file.

Key Concept:

Terraform state management is at the core of "Implement and Maintain State." Understanding where Terraform stores the state by default is critical because state files should often be stored remotely (using a backend like S3, GCS, or Terraform Cloud) for collaboration and reliability.

The terraform state show command allows you to access all of the attributes and details of a resource managed by Terraform. You can use the resource address (e.g. provider_type.name) as an argument to show the information about a specific resource. The terraform state list command only shows the list of resources in the state, not their attributes. The terraform get command downloads and installs modules needed for the configuration. It does not show any information about resources. References = [Command: state show] and [Command: state list]

This is one disadvantage of using dynamic blocks in Terraform, as they can introduce complexity and reduce readability of the configuration. The other options are either advantages or incorrect statements.

Rationale for Correct Answer:

C: Securely managed .tfvars files are acceptable if not committed to version control.

D: HCP Terraform provides secure storage for sensitive variables.

E: HashiCorp Vault is designed for secrets management and integrates with Terraform.

Analysis of Incorrect Options (Distractors):

A: Plaintext storage is insecure.

B: Secrets should never be committed to version control.

Key Concept:Sensitive values must be stored using secure secret management solutions.

You should run terraform fmt to rewrite all Terraform configurations within the current working directory to conform to Terraform-style conventions. This command applies a subset of the Terraform language style conventions, along with other minor adjustments for readability. It is recommended to use this command to ensure consistency of style across different Terraform codebases. The command is optional, opinionated, and has no customization options, but it can help you and your team understand the code more quickly and easily. References = : Command: fmt : Using Terraform fmt Command to Format Your Terraform Code

This is not a responsibility of a Terraform provider, as it does not make sense grammatically or logically. A Terraform provider is responsible for exposing resources and data sources based on an API, managing actions to take based on resource differences, and understanding API interactions with some service.

This is the command that always causes a state file to be updated with changes that might have been made outside of Terraform, as it will only refresh the state file with the current status of the real resources, without making any changes to them or creating a plan.

The terraform refresh-only command is intended to detect state file drift. This command synchronizes the state file with the actual infrastructure, updating the state to reflect any changes that have occurred outside of Terraform.

From terraform plan -refresh-only:

"Use this to detectdrift, i.e., changes made outside of Terraform."

It compares actual infrastructure to what's recorded in the state file.

This is a bad practice, as it exposes your credentials to anyone who can access your configuration files or state files. You should use environment variables, credential files, or other mechanisms to provide credentials to Terraform.

You need to write Terraform configuration files for the existing infrastructure that you want to import into Terraform, otherwise Terraform will not know how to manage it. The configuration files should match the type and name of the resources that you want to import.

The terraform import command is used to import existing infrastructure into your Terraform state. This command takes the existing resource and associates it with a resource defined in your Terraform configuration, updating the state file accordingly. It does not generate configuration for the resource, only the state.

Terraform detects infrastructure drift by comparing thestate filewith the actual infrastructure.

When an instance ismanually deleted, Terraformsees it as missingand marks it for recreation.

Running terraform apply willonly recreate the missing instanceswhile leaving the rest of the infrastructure unchanged.

Explanation of incorrect answers:

A (Tear down everything and rebuild)– Incorrect. Terraform does not destroy existing infrastructure unless explicitly told to.

B (Build a completely new set of infrastructure)– Incorrect. Terraform does not create duplicates unless configuration changes.

D (Stop and error out)– Incorrect. Terraform does not fail; itrebuilds missing resourcesautomatically.

Official Terraform Documentation Reference:

Handling Infrastructure Drift

Rationale for Correct Answer:terraform state list only reads the existing state file and lists the resources Terraform currently tracks. It does not contact providers or refresh resource data, so stale state is not updated.

Analysis of Incorrect Options (Distractors):

B. terraform plan: Refreshes state by default before generating the execution plan.

C. terraform apply: Refreshes state before applying changes.

D. terraform destroy: Refreshes state to determine what resources must be destroyed.

Key Concept:Some Terraform commands read state only, while others refresh state by querying providers.

terraform validate does not confirm that your infrastructure matches the Terraform state file. It only checks whether the configuration files in a directory are syntactically valid and internally consistent3. To confirm that your infrastructure matches the Terraform state file, you need to use terraform plan or terraform apply with the -refresh-only option.

C (✅Correct)– InHCP Terraform, you can use the terraform_remote_state data source to referenceanother workspace's state. This feature isnot available in Terraform CLI.

A (❌Incorrect)– terraform plan (dry runs)is available in both Terraform CLI and HCP Terraform.

B (❌Incorrect)– Secure variable storageexists in HCP Terraform, but CLI users can store variables securely using environment variables or .tfvars files.

D (❌Incorrect)– BothTerraform CLI and HCP Terraform support multiple cloud providers.

Official Terraform Documentation Reference:

terraform_remote_state - HashiCorp Documentation

HashiCorp Configuration Language (HCL) does not support user-defined functions. You can only use the built-in functions that are provided by the language. The built-in functions allow you to perform various operations and transformations on values within expressions. The general syntax for function calls is a function name followed by comma-separated arguments in parentheses, such as max(5, 12, 9). You can find the documentation for all of the available built-in functions in the Terraform Registry orthe Packer Documentation, depending on which tool you are using. References = : Functions - Configuration Language | Terraform : Functions - Configuration Language | Packer

In Terraform, the correct way to reference a resource attribute is:

pgsql

CopyEdit

resource_type.resource_name.attribute

For example, if the resource block is:

hcl

CopyEdit

resource "kubernetes_namespace" "example" {

metadata {

name = "my-namespace"

}

}

To reference the name attribute, use:

pgsql

CopyEdit

kubernetes_namespace.example.name

Explanation of incorrect answers:

A (resource.kubernetes_namespace.example.name)– Incorrect. Terraform does not use the resource. prefix when referencing resources.

C (data.kubernetes.namespace.name)– Incorrect. This syntax is used fordata sources, not resources.

D (kubernetes_namespace.test.name)– Incorrect. The resource name is "example", not "test".

Official Terraform Documentation Reference:

Terraform Resource References

Sentinel is a policy-as-code framework that integrates with Terraform Cloud to enforce security, compliance, and governance rules. You can enforce rules such as approved AMIs and ensure security best practices. Policies are written in the Sentinel language, not HCL.

These are two ways to produce a list of the IDs from a list of objects that have an attribute id, using either a for expression or a splat expression syntax.

From the Terraform Output Docs – Sensitive:

"Marking an output as sensitive prevents Terraform from showing its value in the CLI output,but it will still bestored in the state file."

Thus, it protects display, not storage.

In the given Terraform configuration snippet:

resource "aws_vpc" "main" {

name = "test"

}

The provider for the resource aws_vpc is aws. The provider is specified by the prefix of the resource type. In this case, aws_vpc indicates that the resource type vpc is provided by the aws provider.

Terraform workspaces allow you to create multiple states but still be associated with your current code. Workspaces are like “environments” (e.g. staging, production) for the same configuration. You can use workspaces to spin up a copy of your production deployment for testing purposes without having to configure a new state backend. Terraform data sources, local values, and modules are not features that allow you to create multiple states. References = Workspaces and How to Use Terraform Workspaces

This is the correct way to reference the volume IDs associated with the ebs_block_device blocks in this configuration, using the splat expression syntax. The other options are either invalid or incomplete.

Setting the TF_LOG environment variable to DEBUG causes debug messages to be logged into stdout, along with other log levels such as TRACE, INFO, WARN, and ERROR. This can be useful for troubleshooting or debugging purposes.

Rationale for Correct Answer (B):

Terraform interacts with external systems through providers. Since this is a new proprietary service with its own API, Terraform does not support it by default. You would need to develop a custom provider that implements Terraform’s provider interface and interacts with the proprietary APIs to manage resources like users.

Analysis of Incorrect Option:

A. Any service hosted on a public cloud provider: Not true. Terraform can only manage services that have providers (official or custom). Just being "hosted on a public cloud" doesn’t guarantee Terraform support.

Key Concept:

Terraform providers act as the bridge between Terraform and external APIs. For unsupported services, a custom provider must be developed.

If you update the version constraint in your Terraform configuration, Terraform will update your lock file the next time you run terraform init3. This will ensure that you use the same provider versions across different machines and runs.

Runningterraform destroywill show all resources that will be deleted before prompting for approval. You can also runterraform plan -destroyto simulate the destruction without actually applying it, which is useful for reviewing the planned changes.

Dynamic blocks in Terraform allow you to define multiple nested blocks within a resource based on the values of a variable. This feature is particularly useful for scenarios where the number of nested blocks is not fixed and can change based on variable input.