github.com/rstandt/terraform@v0.12.32-0.20230710220336-b1063613405c/website/docs/configuration/functions.html.md (about)

     1  ---
     2  layout: "functions"
     3  page_title: "Functions - Configuration Language"
     4  sidebar_current: "docs-config-functions"
     5  description: |-
     6    The Terraform language has a number of built-in functions that can be called
     7    from within expressions to transform and combine values.
     8  ---
     9  
    10  # Built-in Functions
    11  
    12  -> **Note:** This page is about Terraform 0.12 and later. For Terraform 0.11 and
    13  earlier, see
    14  [0.11 Configuration Language: Interpolation Syntax](../configuration-0-11/interpolation.html).
    15  
    16  The Terraform language includes a number of built-in functions that you can
    17  call from within expressions to transform and combine values. The general
    18  syntax for function calls is a function name followed by comma-separated
    19  arguments in parentheses:
    20  
    21  ```hcl
    22  max(5, 12, 9)
    23  ```
    24  
    25  For more details on syntax, see
    26  [_Function Calls_](./expressions.html#function-calls)
    27  on the Expressions page.
    28  
    29  The Terraform language does not support user-defined functions, and so only
    30  the functions built in to the language are available for use. The navigation
    31  for this section includes a list of all of the available built-in functions.
    32  
    33  You can experiment with the behavior of Terraform's built-in functions from
    34  the Terraform expression console, by running
    35  [the `terraform console` command](/docs/commands/console.html):
    36  
    37  ```
    38  > max(5, 12, 9)
    39  12
    40  ```
    41  
    42  The examples in the documentation for each function use console output to
    43  illustrate the result of calling the function with different parameters.