Question

Why is my Node.js asynchronous function returning undefined when using async/await?

I'm working with an asynchronous function in Node.js using async/await, but it's returning undefined. Can someone help me figure out what might be going wrong?

Answer 1

Your Node.js asynchronous function might return undefined when using async/await if:

You are not returning a value inside the async function.

Every async function must explicitly return the value you want to resolve. If no value is returned, the function resolves to undefined.

Example:

async function fetchData() {

  const data = await someAsyncOperation();

  // Missing return statement

}

const result = await fetchData(); // result will be undefined

Fix:

async function fetchData() {

  const data = await someAsyncOperation();

  return data; // Explicitly return the value

}

const result = await fetchData(); // result will now have the resolved value

You are not awaiting the async function's result.

If you call an async function but don't use await, it returns a Promise, which can appear as undefined if not resolved.

Example:

async function fetchData() {

  return await someAsyncOperation();

}

const result = fetchData(); // result is a Promise, not the resolved value

Fix:

const result = await fetchData(); // Now resolves to the actual value