Promise: any vs race vs all in simple terms

#webdev #javascript #beginners #programming

In short:

Promise.all: Returns all resolved values or first rejected.

Promise.any: Returns first resolved or aggregated all errors

Promise.race: Returns first resolved or rejected

Example1:

const promise1 = Promise.resolve("Hello");
const promise2 = Promise.resolve("World");
const promise3 = Promise.resolve("!");

Promise.all([promise1, promise2, promise3])
  .then((results) => console.log("Success:" + results))
  .catch((error) => console.log("Error:" + error));

> Success:Hello,World,!

Promise.any([promise1, promise2, promise3])
  .then((results) => console.log("Success:" + results))
  .catch((error) => console.log("Error:" + error));

> Success:Hello

Promise.race([promise1, promise2, promise3])
  .then((results) => console.log("Success:" + results))
  .catch((error) => console.log("Error:" + error));

> Success:Hello

Example2:

const promise1 = Promise.resolve("Hello");
const promise2 = Promise.resolve("World");
const promise3 = Promise.reject("!");

Promise.all([promise1, promise2, promise3])
  .then((results) => console.log("Success:" + results))
  .catch((error) => console.log("Error:" + error));

> Error:!

Promise.any([promise1, promise2, promise3])
  .then((results) => console.log("Success:" + results))
  .catch((error) => console.log("Error:" + error));

> Success:Hello

Promise.race([promise1, promise2, promise3])
  .then((results) => console.log("Success:" + results))
  .catch((error) => console.log("Error:" + error));

> Success:Hello

Example3:

const promise1 = Promise.reject("Hello");
const promise2 = Promise.resolve("World");
const promise3 = Promise.resolve("!");

Promise.all([promise1, promise2, promise3])
  .then((results) => console.log("Success:" + results))
  .catch((error) => console.log("Error:" + error));

> Error:Hello

Promise.any([promise1, promise2, promise3])
  .then((results) => console.log("Success:" + results))
  .catch((error) => console.log("Error:" + error));

> Success:World

Promise.race([promise1, promise2, promise3])
  .then((results) => console.log("Success:" + results))
  .catch((error) => console.log("Error:" + error));

> Error:Hello

Example4:

const promise1 = Promise.reject("Hello");
const promise2 = Promise.reject("World");
const promise3 = Promise.reject("!");

Promise.all([promise1, promise2, promise3])
  .then((results) => console.log("Success:" + results))
  .catch((error) => console.log("Error:" + error));

> Error:Hello

Promise.any([promise1, promise2, promise3])
  .then((results) => console.log("Success:" + results))
  .catch((error) => console.log("Error:" + error));

> Error:AggregateError: All promises were rejected

Promise.race([promise1, promise2, promise3])
  .then((results) => console.log("Success:" + results))
  .catch((error) => console.log("Error:" + error));

> Error:Hello