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Function: union()

Call Signature​

union<T>(items1, items2, isEqual?): T[]

Defined in: collection/setOps/index.ts:37

Merges two collections, removing duplicates using a custom comparator.

Similar to Set union operation but works with objects and custom equality.

Type Parameters​

T​

T

Parameters​

items1​

readonly T[]

First collection

items2​

readonly T[]

Second collection

isEqual?​

Comparator<T>

Custom equality function (defaults to reference equality)

Returns​

T[]

Union of both collections without duplicates

Example​

// Data-first - with primitive values
union([1, 2, 3], [3, 4, 5])
// => [1, 2, 3, 4, 5]

// With objects and custom comparator
const users1 = [{ id: 1, name: 'Alice' }]
const users2 = [{ id: 1, name: 'Alice' }, { id: 2, name: 'Bob' }]

union(users1, users2, (a, b) => a.id === b.id)
// => [{ id: 1, name: 'Alice' }, { id: 2, name: 'Bob' }]

// Data-last (in pipe)
pipe(
  users1,
  union(users2, (a, b) => a.id === b.id)
)

See​

  • intersect - for finding common elements
  • symmetricDiff - for finding differences

Call Signature​

union<T>(items2, isEqual?): (items1) => T[]

Defined in: collection/setOps/index.ts:42

Merges two collections, removing duplicates using a custom comparator.

Similar to Set union operation but works with objects and custom equality.

Type Parameters​

T​

T

Parameters​

items2​

readonly T[]

Second collection

isEqual?​

Comparator<T>

Custom equality function (defaults to reference equality)

Returns​

Union of both collections without duplicates

(items1): T[]

Parameters​

items1​

readonly T[]

Returns​

T[]

Example​

// Data-first - with primitive values
union([1, 2, 3], [3, 4, 5])
// => [1, 2, 3, 4, 5]

// With objects and custom comparator
const users1 = [{ id: 1, name: 'Alice' }]
const users2 = [{ id: 1, name: 'Alice' }, { id: 2, name: 'Bob' }]

union(users1, users2, (a, b) => a.id === b.id)
// => [{ id: 1, name: 'Alice' }, { id: 2, name: 'Bob' }]

// Data-last (in pipe)
pipe(
  users1,
  union(users2, (a, b) => a.id === b.id)
)

See​

  • intersect - for finding common elements
  • symmetricDiff - for finding differences