flatMap
Functions
flatMap()
flatMap<
T,U>(arrayOrPromise,callbackfn):Promise<U[]>
Calls a defined callback function on each element of an array, and then flattens the result into a new array.
Type Parameters
| Type Parameter |
|---|
T |
U |
Parameters
| Parameter | Type | Description |
|---|---|---|
arrayOrPromise | T[] | Promise<T[]> | The array or Promise of an array to iterate over. |
callbackfn | (value, index, array) => U[] | Promise<U[]> | A function that accepts up to three arguments. The flatMap method calls the callbackfn function one time for each element in the array. |
Returns
Promise<U[]>
A Promise that resolves with a new array with the results of calling a provided function on every element in the calling array and flattening the result into a new array.
Example
const array = [1, 2, 3, 4];
const result = await flatMap(array, (value) => [value, value * 2]);
console.log(result); // Output: [1, 2, 2, 4, 3, 6, 4, 8]