docs-v2/content/flux/v0.x/stdlib/experimental/array/map.md

title	description	menu	weight	flux/v0.x/tags	introduced
array.map() function	`array.map` iterates over an array, applies a function to each element to produce a new element, and then returns a new array.	flux_0_x_ref name parent array.map exp-array	301	array	0.155.0

array.map() iterates over an array, applies a function to each element to produce a new element, and then returns a new array.

import "experimental/array"

array.map(
    arr: [1, 2, 3, 4],
    fn: (x) => x * 2,
)

// Returns [2, 4, 6, 8]

Parameters

arr

Array to operate on. Default is the piped-forward array (<-).

fn

Function to apply to elements. The element is represented by x in the function.

Examples

Convert an array of integers to an array of records

import "experimental/array"

a = [1, 2, 3, 4, 5]
b = a |> array.map(fn: (x) => ({_value: x}))
// b returns [{_value: 1}, {_value: 2}, {_value: 3}, {_value: 4}, {_value: 5}]

// Output the array of records as a table
> array.from(rows: b)

Iterate over and modify an array of records

a = 
    [
        {a: 1, b: 2, c: 3},
        {a: 4, b: 5, c: 6},
        {a: 7, b: 8, c: 9},
    ]

b = a |> array.map(fn: (x) => ({x with a: x.a * x.a, d: x.b + x.c}))
// b returns:
// [
//     {a: 1, b: 2, c: 3, d: 5},
//     {a: 16, b: 5, c: 6, d: 11},
//     {a: 49, b: 8, c: 9, d: 17}
// ]

// Output the modified array of records as a table
array.from(rows: b)