Waiting On Multiple Asynchronous Calls To Complete Before Continuing

Are you working on a project that requires you to wait for multiple asynchronous calls to finish before proceeding? You're in luck! In this article, we'll go over some helpful tips and techniques to handle this common scenario in software engineering.

Using Promises in JavaScript is a great way to deal with asynchronous operations and manage their completion. When you have multiple asynchronous calls that need to be made, you can use Promise.all() to wait for all of them to complete before moving forward in your code.

Here's a simple example to demonstrate how you can wait for multiple asynchronous calls to complete using Promise.all():

Javascript

const asyncCall1 = () =&gt; {
  return new Promise((resolve) =&gt; {
    setTimeout(() =&gt; {
      console.log("Async Call 1 Finished");
      resolve();
    }, 2000);
  });
};

const asyncCall2 = () =&gt; {
  return new Promise((resolve) =&gt; {
    setTimeout(() =&gt; {
      console.log("Async Call 2 Finished");
      resolve();
    }, 3000);
  });
};

Promise.all([asyncCall1(), asyncCall2()]).then(() =&gt; {
  console.log("All Async Calls Completed. Proceeding...");
  // Add your code to run after all async calls are finished here
});

In this code snippet, we have two asynchronous functions, asyncCall1 and asyncCall2, each representing a separate asynchronous operation. We then use Promise.all() to wait for both functions to resolve before executing the code inside the then() block.

Additionally, you can handle errors in asynchronous calls by wrapping your promises in a try/catch block. This will allow you to gracefully handle any errors that may occur during the asynchronous operations.

Javascript

const asyncCallWithError = () =&gt; {
  return new Promise((resolve, reject) =&gt; {
    setTimeout(() =&gt; {
      console.log("Async Call with Error");
      reject(new Error("Something went wrong"));
    }, 2500);
  });
};

Promise.all([asyncCall1(), asyncCall2(), asyncCallWithError()])
  .then(() =&gt; {
    console.log("All Async Calls Completed. Proceeding...");
    // Add your code to run after all async calls are finished here
  })
  .catch((error) =&gt; {
    console.error("Error occurred:", error.message);
    // Handle the error appropriately
  });

By using the above approach, you can effectively manage multiple asynchronous calls and ensure that all operations are completed before moving forward with your code execution. This technique can help improve the efficiency and reliability of your software applications.

In conclusion, waiting for multiple asynchronous calls to complete before continuing in your code is a common requirement in software development. By utilizing Promises and tools like Promise.all(), you can effectively manage asynchronous operations and ensure that your code runs smoothly and efficiently.

Related posts:

Contact Info