How to Ensure a Callback is Executed After All Asynchronous Operations in a forEach Loop Complete?

Asynchronous forEach Completion Callback

Problem:

How to execute a callback when all asynchronous operations within a forEach loop have completed?

Solution:

1. Using a Simple Counter:

Initialize a counter itemsProcessed to 0. Increment the counter in the callback of each asynchronous function. When itemsProcessed reaches the total array length, invoke the "all done" callback.

2. Using ES6 Promises:

Create an array of Promise objects representing each asynchronous operation using Promise.all. When all Promises have completed, the final callback will be executed.

3. Using an Async Library:

Utilize async libraries like async to provide mechanisms for expressing asynchronous completion callbacks.

Revised Example (Counter Method):

<code class="javascript">function callback() {
  console.log("All done!");
}

var itemsProcessed = 0;

[1, 2, 3].forEach((item, index, array) => {
  asyncFunction(item, () => {
    itemsProcessed++;
    if (itemsProcessed === array.length) {
      callback();
    }
  });
});</code>

Revised Expected Output:

3 done
1 done
2 done
All done!

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