JavaScript Masterclass - Zero to Job-Ready with Hands-On Projects - Promises All / 186

The lecture explains how to use Promise.all in JavaScript to handle multiple promises simultaneously. It covers creating promises for Twitter and Instagram profiles, using resolve and reject, and demonstrates how Promise.all can be used to execute these promises together. The timing and execution behavior of Promise.all is discussed, with practical examples and console logs to illustrate the concept.

What is the primary purpose of using Promise.all in JavaScript?

• To reject all promises at once

• To resolve multiple promises together

• To create a new promise from scratch

• To execute a single promise multiple times

When creating a promise, which two functions are typically used to handle the outcome?

• Resolve and Reject

• Start and Stop

• Accept and Decline

• Open and Close

What happens when two promises have different timeouts and are not handled by Promise.all?

• They both reject immediately

• The promise with the longer timeout resolves first

• The promise with the shorter timeout resolves first

• They resolve at the same time

How does Promise.all handle the resolution of multiple promises?

• It resolves them one by one in sequence

• It resolves them together and returns an array of results

• It rejects all if one promise fails

• It ignores the promises with longer timeouts

In the context of Promise.all, what does the array returned contain?

• The rejected values of the promises

• The resolved values of the promises

• The promises themselves

• The execution time of each promise

What is the sequence of the resolved values in the array returned by Promise.all?

• In the order of promise creation

• In reverse order of promise creation

• In the order of promise resolution

• In alphabetical order

What happens if one promise in Promise.all is rejected?

• Promise.all ignores the rejected promise

• Promise.all waits for all promises to resolve

• Promise.all immediately rejects with the reason of the first promise that rejects

• All promises are resolved