Conditional Expressions

Explore how to use arithmetic, comparison, equality, logical, and conditional operators in OpenTofu configurations and the interactive console.

Table of Contents

• Interactive Arithmetic in the Console
• Equality & Inequality Operators
• Comparison Operators
• Logical Operators & NOT
• Defining Variables and Testing Expressions
• Ternary (Conditional) Expressions in Configurations
• References

Interactive Arithmetic in the Console

You can quickly evaluate math expressions in the OpenTofu console:

$ tofu console
> 1 + 2
3
> 10 / 4
2.5
> 7 * (3 - 1)
14

Equality & Inequality Operators

Equality and inequality comparisons return a Boolean. Use them to compare values of any type:

$ tofu console
> 8 == 8
true
> 8 != "8"
true
> 8 == "8"
false

Comparison Operators

Numeric comparisons also yield Boolean results. Here’s a quick reference:

$ tofu console
> 5 > 7
false
> 4 <= 5
true

Logical Operators & NOT

Combine Boolean expressions using AND (&&) and OR (||), and invert them with NOT (!):

$ tofu console
> (8 > 7) && (8 < 10)
true
> (8 > 10) || (8 < 10)
true
> !(8 == 8)
false

Defining Variables and Testing Expressions

You can declare variables in HCL and reference them in the console:

variable "a" {
  type    = number
  default = 50
}

variable "b" {
  type    = number
  default = 25
}

$ tofu console
> var.a > var.b
true
> var.a + var.b
75

Ternary (Conditional) Expressions in Configurations

Use the ternary operator (condition ? true_val : false_val) to enforce defaults. For example, generate a random password whose length is at least 8 characters:

variable "length" {
  type        = number
  description = "Desired password length (minimum 8)"
}

resource "random_password" "password_generator" {
  length = var.length < 8 ? 8 : var.length
}

output "password" {
  value     = random_password.password_generator.result
  sensitive = true
}

Initialize, plan, and apply:

$ tofu init
$ tofu plan -var='length=5'
$ tofu apply -var='length=5' -auto-approve

Even if you pass length=5, OpenTofu generates an 8-character password. Passing a higher value (e.g., 12) yields a 12-character result.

References

• OpenTofu Documentation
• Random Provider: random_password Resource
• Terraform Expressions