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intersection (Lodash Compatibility) ​

Use intersection from es-toolkit

This intersection function operates slowly due to handling null or undefined, multiple array support, and duplicate removal process.

Instead, use the faster and more modern intersection from es-toolkit.

Finds the intersection of multiple arrays.

typescript
const result = intersection(...arrays);

Reference ​

intersection(...arrays) ​

Finds elements that exist in all arrays and returns them as a new array. The result is deduplicated and maintains the order of the first array.

typescript
import { intersection } from 'es-toolkit/compat';

// Intersection of two arrays
const array1 = [1, 2, 3, 4];
const array2 = [2, 3, 5, 6];
const result = intersection(array1, array2);
// result is [2, 3]

// Intersection of three arrays
const array3 = [3, 4, 7, 8];
const multiResult = intersection(array1, array2, array3);
// multiResult is [3]

// String arrays
const strings1 = ['a', 'b', 'c'];
const strings2 = ['b', 'c', 'd'];
const stringResult = intersection(strings1, strings2);
// stringResult is ['b', 'c']

// Array-like objects
const arrayLike1 = { 0: 1, 1: 2, 2: 3, length: 3 };
const arrayLike2 = { 0: 2, 1: 3, 2: 4, length: 3 };
const likeResult = intersection(arrayLike1, arrayLike2);
// likeResult is [2, 3]

null or undefined arrays are treated as empty arrays.

typescript
import { intersection } from 'es-toolkit/compat';

const array1 = [1, 2, 3];
const result1 = intersection(array1, null);
// result1 is []

const result2 = intersection(null, undefined);
// result2 is []

Duplicate elements are removed from the result.

typescript
import { intersection } from 'es-toolkit/compat';

const array1 = [1, 1, 2, 3];
const array2 = [1, 2, 2, 4];
const result = intersection(array1, array2);
// result is [1, 2] (duplicates removed)

Parameters ​

  • ...arrays (Array<ArrayLike<T> | null | undefined>): The arrays to find the intersection of. Array-like objects, null, or undefined are also allowed.

Returns ​

(T[]): Returns a new array of elements that exist in all arrays. Duplicates are removed and the order follows the first array.

Released under the MIT License.