34 lines
846 B
Markdown
34 lines
846 B
Markdown
---
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layout: "functions"
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page_title: "flatten - Functions - Configuration Language"
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sidebar_current: "docs-funcs-collection-flatten"
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description: |-
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The flatten function eliminates nested lists from a list.
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---
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# `flatten` Function
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-> **Note:** This page is about Terraform 0.12 and later. For Terraform 0.11 and
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earlier, see
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[0.11 Configuration Language: Interpolation Syntax](../../configuration-0-11/interpolation.html).
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`flatten` takes a list and replaces any elements that are lists with a
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flattened sequence of the list contents.
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## Examples
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```
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> flatten([["a", "b"], [], ["c"]])
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["a", "b", "c"]
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```
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If any of the nested lists also contain directly-nested lists, these too are
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flattened recursively:
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```
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> flatten([[["a", "b"], []], ["c"]])
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["a", "b", "c"]
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```
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Indirectly-nested lists, such as those in maps, are _not_ flattened.
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