Question 25

Question

Explain how to use async/await with non-Promise values.

Answer

You can't directly use await on a regular value (like a number or string).

Here's how you handle situations where you need to work with non-Promise values in an async context:

1. Converting to a Promise:

The most common approach is to wrap the non-Promise value into a resolved Promise. This signals that the operation is complete and the value is available.

async function myAsyncFunction() {
  const someValue = 42; // Non-Promise value

  // Wrap it in a promise that immediately resolves
  const promiseValue = new Promise(resolve => resolve(someValue));

  const result = await promiseValue; 
  console.log(result); // Output: 42
}

myAsyncFunction(); 

Explanation:

• We create a Promise that immediately resolves with the someValue. This fulfills the Promise, making it behave like an asynchronous operation.

• await can then be used on this resolved Promise to access the value asynchronously.

2. Handling Synchronous Operations:

If the non-Promise value is generated synchronously (e.g., a calculation), you might not need async/await.

function myFunction() {
  const someValue = 42; // Non-Promise value
  console.log(someValue); // Outputs immediately
}

myFunction(); // Executes immediately

Important Considerations:

• Purpose of async/await: Remember that async/await is primarily designed for handling asynchronous operations where results might take time to become available (like network requests, file I/O).

• If you are simply working with synchronous data, there's often no need to wrap it in Promises. Using Promises unnecessarily can add complexity to your code without any performance benefit.