map

map(array, fn) → array · Array

Transform every element of an array. The most-used function in UTL-X. Returns a new array of the same length.

array (required): the array to transform
fn (required): lambda (element) -> newValue or (element, index) -> newValue

bash

echo '[1, 2, 3]' | utlx -e 'map(., (x) -> x * 2)'
# [2, 4, 6]

utlx

{
  lines: map($input.items, (item) -> {
    product: item.name,
    priceWithTax: item.price * 1.21
  }),

  // With index (second parameter):
  numbered: map($input.items, (item, index) -> {
    lineNumber: index + 1,
    product: item.name
  })
}

Anti-pattern: using map() to filter — map(arr, (x) -> if (x.active) x else null) produces nulls. Use filter() to remove, then map() to transform.

map ​

map