99 lines
2.0 KiB
Markdown
99 lines
2.0 KiB
Markdown
---
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title: array.map() function
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description: >
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`array.map()` iterates over an array, applies a function to each element to produce a new element,
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and then returns a new array.
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menu:
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flux_v0_ref:
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name: array.map
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parent: array
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identifier: array/map
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weight: 101
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introduced: 0.173.0
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---
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<!------------------------------------------------------------------------------
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IMPORTANT: This page was generated from comments in the Flux source code. Any
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edits made directly to this page will be overwritten the next time the
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documentation is generated.
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To make updates to this documentation, update the function comments above the
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function definition in the Flux source code:
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https://github.com/influxdata/flux/blob/master/stdlib/array/array.flux#L101-L101
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Contributing to Flux: https://github.com/influxdata/flux#contributing
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Fluxdoc syntax: https://github.com/influxdata/flux/blob/master/docs/fluxdoc.md
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------------------------------------------------------------------------------->
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`array.map()` iterates over an array, applies a function to each element to produce a new element,
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and then returns a new array.
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##### Function type signature
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```js
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(<-arr: [A], fn: (x: A) => B) => [B]
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```
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{{% caption %}}
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For more information, see [Function type signatures](/flux/v0/function-type-signatures/).
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{{% /caption %}}
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## Parameters
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### arr
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Array to operate on. Defaults is the piped-forward array (`<-`).
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### fn
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({{< req >}})
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Function to apply to elements. The element is represented by `x` in the function.
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## Examples
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### Convert an array of integers to an array of records
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```js
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import "array"
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a = [
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1,
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2,
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3,
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4,
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5,
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]
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b = a |> array.map(fn: (x) => ({_value: x}))
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// b returns [{_value: 1}, {_value: 2}, {_value: 3}, {_value: 4}, {_value: 5}]
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// Output the array of records as a table
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array.from(rows: b)
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```
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{{< expand-wrapper >}}
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{{% expand "View example output" %}}
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#### Output data
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| _value |
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| ------- |
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| 1 |
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| 2 |
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| 3 |
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| 4 |
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| 5 |
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{{% /expand %}}
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{{< /expand-wrapper >}}
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