filter

filter(array, predicate) → array · Array

Keep elements that match a predicate. Always returns an array (even if 0 or 1 match).

array (required): the array to filter
predicate (required): lambda (element) -> boolean

bash

echo '[{"name":"Alice","active":true},{"name":"Bob","active":false}]' \
  | utlx -e 'filter(., (u) -> u.active)'
# [{"name": "Alice", "active": true}]

utlx

{
  activeProducts: filter($input.products, (p) -> p.active),
  premiumActive: filter($input.products, (p) -> p.price > 100 && p.active),
  overBudget: filter($input.products, (p) -> p.price > 1000)
}

Anti-pattern: $input.products[price > 10] — bracket predicate syntax does NOT work in UTL-X. Always use filter(). See Chapter 8.

Anti-pattern: filter() when you want ONE result — use find() instead (returns the element, not an array).

filter ​

filter