How can we use Promise.race(iteratable)?

javascript-promises

Promise.race is an interesting function. Instead of waiting for all promises to be resolved or rejected, Promise.race triggers as soon as any promise in the iteratable is resolved or rejected:

var req1 = new Promise(function(resolve, reject) { 
    // A mock async action using setTimeout
    setTimeout(function() { resolve('First!'); }, 8000);
});
var req2 = new Promise(function(resolve, reject) { 
    // A mock async action using setTimeout
    setTimeout(function() { resolve('Second!'); }, 3000);
});
Promise.race([req1, req2]).then(function(one) {
    console.log('Then: ', one);
}).catch(function(one, two) {
    console.log('Catch: ', one);
});

// From the console:
// Then: Second!