52 lines
932 B
Markdown
52 lines
932 B
Markdown
---
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title: regexp.findString() function
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description: The `regexp.findString()` function returns the left-most regular expression match in a string.
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menu:
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v2_0_ref:
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name: regexp.findString
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parent: Regular expressions
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weight: 301
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related:
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- /v2.0/reference/flux/functions/regexp/splitregexp
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---
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The `regexp.findString()` function returns the left-most regular expression match in a string.
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_**Output data type:** String_
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```js
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import "regexp"
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findString(r: /foo.?/, v: "seafood fool")
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// Returns "food"
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```
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## Parameters
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### r
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The regular expression used to search `v`.
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_**Data type:** Regexp_
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### v
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The string value to search.
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_**Data type:** String_
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## Examples
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###### Find the first regular expression match in each row
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```js
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import "regexp"
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data
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|> map(fn: (r) => ({
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r with
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message: r.message,
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regexp: r.regexp,
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match: regexp.findString(r: r.regexp, v: r.message)
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})
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)
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```
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