How Can I Use `async/await` with `Array.map` to Handle Asynchronous Operations?

Making async await Work with Array.map

Array.map is a powerful method for transforming each element in an array. However, using it with async operations can introduce challenges.

In the code snippet provided, the error arises because the output of map is an array of promises, not a promise. await expects a promise and returns the resolved value, but with an array, it returns the array itself.

To resolve this issue, Promise.all can be used to convert the array of promises into a single promise. Promise.all waits for all promises in the array to resolve before resolving the single outer promise.

The corrected code:

var arr = [1,2,3,4,5];

var results: number[] = await Promise.all(arr.map(async (item): Promise<number> => {
    await callAsynchronousOperation(item);
    return item + 1;
}));

This modification ensures that the output of Array.map is converted into a single promise, allowing await to resolve the combined result correctly as an array of numbers.

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