In JavaScript, promises are a powerful tool for managing asynchronous operations. However, there may be scenarios where you need to handle multiple promises concurrently. In this blog post, we will explore different approaches to handle concurrent promises in JavaScript.

Table of Contents

• Promise.all()
• Promise.allSettled()
• Using async/await with Promise.all()
• Conclusion

Promise.all()

The Promise.all() method takes an array of promises as input and returns a single promise. This method resolves when all the input promises are resolved or rejects if any of the input promises are rejected.

const promises = [promise1, promise2, promise3];
Promise.all(promises)
  .then(results => {
    // Handle successful resolution of all promises
  })
  .catch(error => {
    // Handle rejection of any promise
  });

By using Promise.all(), you can execute multiple promises concurrently and handle the results collectively.

Promise.allSettled()

ES2020 introduced the Promise.allSettled() method which behaves similarly to Promise.all(), but it resolves with an array of objects containing the status of each promise, whether fulfilled or rejected.

const promises = [promise1, promise2, promise3];
Promise.allSettled(promises)
  .then(results => {
    // Handle all promises, regardless of their status
  });

With Promise.allSettled(), you can handle all promises, even if some of them get rejected.

Using async/await with Promise.all()

Another approach to handle concurrent promises is to use async/await with Promise.all(). This allows you to write asynchronous code in a more synchronous manner.

async function handlePromises() {
  try {
    const results = await Promise.all([promise1, promise2, promise3]);
    // Handle successful resolution of all promises
  } catch (error) {
    // Handle rejection of any promise
  }
}

By using async/await, you can handle multiple promises concurrently while maintaining a more readable and sequential code flow.

Conclusion

Dealing with concurrent promises in JavaScript is made easier with the help of built-in methods such as Promise.all() and Promise.allSettled(). Additionally, by using async/await with Promise.all(), you can write more readable and synchronous-like code.

By choosing the appropriate approach based on your requirements, you can effectively handle concurrent promises in JavaScript.

#javascript #promises