Another usage of variables in Terraform

Let's have the following main.tf:

resource "random_pet" "my-cat" {
  prefix = "Mrs"
  separator = "."
  length = 1
}

So, it can be transformed in a sequence of following files by using variables.
variables.tf:

variable "separator" {
  default = "."
  type = string
  description = "The cat name separator"
}
variable "length" {
  default = 1
  type = number
  description = "Length of generated name"
}
variable "prefix" {
  default = ["Mr", "Mrs", "Sir"]
  type = list
  description = "List of prefixes for cats name"
}

main.tf:

resource "random_pet" "my-cat" {
  prefix = var.prefix[0]
  separator = var.separator
  length = var.length
}

Run plan and apply ro see the results.