26 lines
1.1 KiB
Markdown
26 lines
1.1 KiB
Markdown
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layout: "language"
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page_title: "Expressions - Configuration Language"
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---
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# Expressions
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_Expressions_ are used to refer to or compute values within a configuration.
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The simplest expressions are just literal values, like `"hello"` or `5`,
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but the Terraform language also allows more complex expressions such as
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references to data exported by resources, arithmetic, conditional evaluation,
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and a number of built-in functions.
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Expressions can be used in a number of places in the Terraform language,
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but some contexts limit which expression constructs are allowed,
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such as requiring a literal value of a particular type or forbidding
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[references to resource attributes](/docs/configuration/expressions/references.html#references-to-resource-attributes).
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Each language feature's documentation describes any restrictions it places on expressions.
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You can experiment with the behavior of Terraform's expressions from
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the Terraform expression console, by running
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[the `terraform console` command](/docs/commands/console.html).
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The other pages in this section describe the features of Terraform's
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expression syntax.
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