49 lines
1.4 KiB
Markdown
49 lines
1.4 KiB
Markdown
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---
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layout: "language"
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page_title: "Function Calls - Configuration Language"
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---
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# Function Calls
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The Terraform language has a number of
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[built-in functions](/docs/configuration/functions.html) that can be used
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in expressions to transform and combine values. These
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are similar to the operators but all follow a common syntax:
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```hcl
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<FUNCTION NAME>(<ARGUMENT 1>, <ARGUMENT 2>)
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```
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The function name specifies which function to call. Each defined function
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expects a specific number of arguments with specific value types, and returns a
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specific value type as a result.
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Some functions take an arbitrary number of arguments. For example, the `min`
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function takes any amount of number arguments and returns the one that is
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numerically smallest:
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```hcl
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min(55, 3453, 2)
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```
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A function call expression evaluates to the function's return value.
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## Expanding Function Arguments
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If the arguments to pass to a function are available in a list or tuple value,
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that value can be _expanded_ into separate arguments. Provide the list value as
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an argument and follow it with the `...` symbol:
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```hcl
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min([55, 2453, 2]...)
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```
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The expansion symbol is three periods (`...`), not a Unicode ellipsis character
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(`…`). Expansion is a special syntax that is only available in function calls.
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## Available Functions
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For a full list of available functions, see
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[the function reference](/docs/configuration/functions.html).
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