mirror of
https://github.com/toss/es-toolkit.git
synced 2024-12-18 21:41:46 +03:00
cf65b2c601
* chore: add prettierrc * chore: apply format with prettier config * chore: eslint error fix
35 lines
1.2 KiB
Markdown
35 lines
1.2 KiB
Markdown
# intersectionBy
|
|
|
|
Returns the intersection of two arrays based on a mapping function.
|
|
|
|
This function takes two arrays and a mapping function. It returns a new array containing
|
|
the elements from the first array that, when mapped using the provided function, have matching
|
|
mapped elements in the second array. It effectively filters out any elements from the first array
|
|
that do not have corresponding mapped values in the second array.
|
|
|
|
## Signature
|
|
|
|
```typescript
|
|
function intersectionBy<T, U>(firstArr: T[], secondArr: T[], mapper: (item: T) => U): T[];
|
|
```
|
|
|
|
### Parameters
|
|
|
|
- `firstArr` (`T[]`): The first array to compare.
|
|
- `secondArr` (`T[]`): The second array to compare.
|
|
- `mapper` (`(item: T) => U`): A function to map the elements of both arrays for comparison.
|
|
|
|
### Returns
|
|
|
|
(`T[]`) A new array containing the elements from the first array that have corresponding mapped values in the second array.
|
|
|
|
## Examples
|
|
|
|
```typescript
|
|
const array1 = [{ id: 1 }, { id: 2 }, { id: 3 }];
|
|
const array2 = [{ id: 2 }, { id: 4 }];
|
|
const mapper = item => item.id;
|
|
const result = intersectionBy(array1, array2, mapper);
|
|
// result will be [{ id: 2 }] since only this element has a matching id in both arrays.
|
|
```
|