{"id":31756,"date":"2022-11-11T13:28:46","date_gmt":"2022-11-11T13:28:46","guid":{"rendered":"https:\/\/www.devopsschool.com\/blog\/?p=31756"},"modified":"2022-12-23T05:45:34","modified_gmt":"2022-12-23T05:45:34","slug":"terraform-tutorials-set-data-type-and-example","status":"publish","type":"post","link":"https:\/\/www.devopsschool.com\/blog\/terraform-tutorials-set-data-type-and-example\/","title":{"rendered":"Terraform Tutorials: Set data type and example"},"content":{"rendered":"\n
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set(\u2026): a collection of unique values that do not have any secondary identifiers or ordering.<\/p>\n\n\n\n

Set collections are unordered and cannot contain duplicate values, so the ordering of the argument elements is lost and any duplicate values are coalesced:<\/p>\n\n\n\n

Since Terraform’s concept of a set requires all of the elements to be of the same type, mixed-typed elements will be converted to the most general type:<\/p>\n\n\n\n

<\/p>\n\n\n\n

Example Code<\/h2>\n\n\n\n
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# Slice a set by first casting it to a list and then accessing it as a list.<\/span>\r\n\r\nvariable \"set\"<\/span> {\r\n  type = set(string)\r\n  default<\/span> = [\r\n    \"foo\"<\/span>,\r\n    \"bar\"<\/span>,\r\n  ]\r\n}\r\n\r\noutput \"set\"<\/span> {\r\n  value = var<\/span>.set\r\n}\r\n\r\noutput \"set_first_element\"<\/span> {\r\n  value = var<\/span>.set[0<\/span>]\r\n}\r\n<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
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How to convert list to set type?<\/h2>\n\n\n\n
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Function name – toset<\/p>\n\n\n\n
Similar kinds of complex types (list\/tuple\/set and map\/object) can usually be used interchangeably within the Terraform language, and most of Terraform’s documentation glosses over the differences between the kinds of complex type.<\/p>\n\n\n\n
Pass a list value to toset to convert it to a set, which will remove any duplicate elements and discard the ordering of the elements.<\/p>\n\n\n\n
Explicit type conversions are rarely necessary in Terraform because it will convert types automatically where required. Use the explicit type conversion functions only to normalize types returned in module outputs.<\/p>\n\n\n\n
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\r\nExample\r\n\r\n> toset([\"a\"<\/span>, \"b\"<\/span>, \"c\"<\/span>])\r\n[\r\n  \"a\"<\/span>,\r\n  \"b\"<\/span>,\r\n  \"c\"<\/span>,\r\n]\r\n\r\n> toset([\"a\"<\/span>, \"b\"<\/span>, 3<\/span>])\r\n[\r\n  \"3\"<\/span>,\r\n  \"a\"<\/span>,\r\n  \"b\"<\/span>,\r\n]\r\n\r\n> toset([\"c\"<\/span>, \"b\"<\/span>, \"b\"<\/span>])\r\n[\r\n  \"b\"<\/span>,\r\n  \"c\"<\/span>,\r\n]<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
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Sets are almost similar to both tuples and lists:<\/h2>\n\n\n\n
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    \n
  • When a list or tuple is converted to a set, duplicate values are discarded and the ordering of elements is lost.<\/li>\n\n\n\n
  • When a set is converted to a list or tuple, the elements will be in an arbitrary order. If the set’s elements were strings, they will be in lexicographical order; sets of other element types do not guarantee any particular order of elements.<\/li>\n<\/ul>\n\n\n\n
    Reference<\/strong><\/p>\n\n\n\n
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    • https:\/\/developer.hashicorp.com\/terraform\/language\/expressions\/type-constraints<\/li>\n\n\n\n
    • https:\/\/developer.hashicorp.com\/terraform\/language\/functions\/toset<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"
      set(\u2026): a collection of unique values that do not have any secondary identifiers or ordering. Set collections are unordered and cannot contain duplicate values, so the ordering… <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_joinchat":[],"footnotes":""},"categories":[2],"tags":[],"class_list":["post-31756","post","type-post","status-publish","format-standard","hentry","category-uncategorised"],"_links":{"self":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/31756","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/comments?post=31756"}],"version-history":[{"count":1,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/31756\/revisions"}],"predecessor-version":[{"id":31757,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/31756\/revisions\/31757"}],"wp:attachment":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/media?parent=31756"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/categories?post=31756"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/tags?post=31756"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}