Modern JavaScript (ES2021)

Promise.any()

Get the first success - ignore failures!

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What is Promise.any()?

Promise.any() is the optimistic one! It returns the first successful promise and ignores all rejections. Only fails if ALL promises reject. Perfect for "try multiple sources, use whoever responds first" scenarios!

Opposite of Promise.all()

Promise.all() needs ALL to succeed.Promise.any() needs just ONE to succeed!

Example 1: First Success Wins

Get result from first successful promise

javascript

code

DarkEditable

// Multiple promises with mixed results
const p1 = Promise.reject('Error 1');
const p2 = Promise.resolve('Success!');
const p3 = Promise.reject('Error 3');

Promise.any([p1, p2, p3])
  .then(result => console.log('Result:', result))
  .catch(error => console.log('All failed:', error));
// Result: Success!
// First successful promise wins! ✅

// Simulated API calls with different speeds
function fetchFromServer(name, delay, shouldFail = false) {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (shouldFail) {
        reject(`${name} failed`);
      } else {
        resolve(`Data from ${name}`);
      }
    }, delay);
  });
}

const servers = [
  fetchFromServer('Server 1', 3000, true),   // Slow, fails
  fetchFromServer('Server 2', 1000, false),  // Fast, succeeds ✅
  fetchFromServer('Server 3', 2000, false)   // Medium, succeeds
];

Promise.any(servers)
  .then(data => console.log('Fastest:', data))
  .catch(err => console.log('All failed'));
// Fastest: Data from Server 2
// Server 2 was fastest AND succeeded!

// All rejections case
const allFail = [
  Promise.reject('Error A'),
  Promise.reject('Error B'),
  Promise.reject('Error C')
];

Promise.any(allFail)
  .catch(error => {
    console.log('Type:', error.name);     // AggregateError
    console.log('Errors:', error.errors); // ['Error A', 'Error B', 'Error C']
  });

Console Output

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Example 2: Real-World - Multiple Data Sources

Fetch from fastest available source

javascript

code

DarkEditable

// Fetch from multiple mirrors/CDNs
async function fetchFromFastestSource(url) {
  const sources = [
    fetch(`https://cdn1.example.com${url}`),
    fetch(`https://cdn2.example.com${url}`),
    fetch(`https://cdn3.example.com${url}`)
  ];
  
  try {
    const response = await Promise.any(sources);
    return await response.json();
  } catch (error) {
    throw new Error('All sources failed');
  }
}

// Multiple API fallbacks
async function getUserData(userId) {
  const apis = [
    fetch(`https://api-primary.com/users/${userId}`),
    fetch(`https://api-backup1.com/users/${userId}`),
    fetch(`https://api-backup2.com/users/${userId}`)
  ];
  
  const response = await Promise.any(
    apis.map(p => p.then(r => {
      if (!r.ok) throw new Error('API error');
      return r.json();
    }))
  );
  
  return response;
}

// Try multiple authentication methods
async function authenticate(credentials) {
  const methods = [
    authenticateWithOAuth(credentials),
    authenticateWithSAML(credentials),
    authenticateWithBasic(credentials)
  ];
  
  try {
    const result = await Promise.any(methods);
    console.log('Authenticated successfully');
    return result;
  } catch (error) {
    console.log('All authentication methods failed');
    throw error;
  }
}

// Database read replicas
async function queryDatabase(sql) {
  const replicas = [
    queryReplica('replica-1', sql),
    queryReplica('replica-2', sql),
    queryReplica('replica-3', sql)
  ];
  
  return Promise.any(replicas);
}

Console Output

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Key Takeaways

⚡

First Success

Returns value from first fulfilled promise

🚫

Ignores Rejections

Failures don't matter until all fail

❌

AggregateError

If all fail, throws error with all rejection reasons

🎯

Use Cases

Multiple sources, fallbacks, fastest wins

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Modern JavaScript (ES2021)

Promise.any()

Get the first success - ignore failures!

Find videos you like?

Save to resource drawer for future reference!

What is Promise.any()?

Opposite of Promise.all()

Promise.all() needs ALL to succeed.Promise.any() needs just ONE to succeed!

Example 1: First Success Wins

Get result from first successful promise

javascript

code

DarkEditable

// Multiple promises with mixed results
const p1 = Promise.reject('Error 1');
const p2 = Promise.resolve('Success!');
const p3 = Promise.reject('Error 3');

Promise.any([p1, p2, p3])
  .then(result => console.log('Result:', result))
  .catch(error => console.log('All failed:', error));
// Result: Success!
// First successful promise wins! ✅

Promise.any(servers)
  .then(data => console.log('Fastest:', data))
  .catch(err => console.log('All failed'));
// Fastest: Data from Server 2
// Server 2 was fastest AND succeeded!

// All rejections case
const allFail = [
  Promise.reject('Error A'),
  Promise.reject('Error B'),
  Promise.reject('Error C')
];

Promise.any(allFail)
  .catch(error => {
    console.log('Type:', error.name);     // AggregateError
    console.log('Errors:', error.errors); // ['Error A', 'Error B', 'Error C']
  });

Console Output

Click "Run Code" to see output here...

Example 2: Real-World - Multiple Data Sources

Fetch from fastest available source

javascript

code

DarkEditable

Console Output

Click "Run Code" to see output here...

Key Takeaways

⚡

First Success

Returns value from first fulfilled promise

🚫

Ignores Rejections

Failures don't matter until all fail

❌

AggregateError

If all fail, throws error with all rejection reasons

🎯

Use Cases

Multiple sources, fallbacks, fastest wins

Coder Pod - Learn Programming Online | AI Coding Tutor & Interview Practice

Numeric Separators

String.replaceAll

JavaScript Code Editor

Building Your Learning Module...

Promise.any()

What is Promise.any()?

Opposite of Promise.all()

Example 1: First Success Wins

Example 2: Real-World - Multiple Data Sources

Key Takeaways

First Success

Ignores Rejections

AggregateError

Use Cases

Numeric Separators

String.replaceAll

JavaScript Code Editor

Promise.any()

What is Promise.any()?

Opposite of Promise.all()

Example 1: First Success Wins

Example 2: Real-World - Multiple Data Sources

Key Takeaways

First Success

Ignores Rejections

AggregateError

Use Cases