JAVASCRIPT
javascript promise all
var p1 = Promise.resolve(3);
var p2 = 1337;
var p3 = new Promise((resolve, reject) => {
setTimeout(resolve, 100, "foo");
});
Promise.all([p1, p2, p3]).then(values => {
console.log(values); // [3, 1337, "foo"]
});
Promise.all
const promise1 = Promise.resolve(3);
const promise2 = 42;
const promise3 = new Promise(function(resolve, reject) {
setTimeout(resolve, 100, 'foo');
});
Promise.all([promise1, promise2, promise3]).then(function(values) {
console.log(values);
});
// expected output: Array [3, 42, "foo"]
javascript promise.all
try {
const [res1, res2, res3] = await Promise.all([
Promise1,
Promise2,
Promise3,
]);
} catch (err) {
console.error(err);
}
javascript promise.all
// PARALLEL PROMISES
async function fetchMoviesAndCategories() {
const [moviesResponse, categoriesResponse] = await Promise.all([
fetch('/movies'),
fetch('/categories')
]);
const movies = await moviesResponse.json();
const categories = await categoriesResponse.json();
return [movies, categories];
}
javascript promise all
var p1 = new Promise((resolve, reject) => {
setTimeout(resolve, 1000, "one");
});
var p2 = new Promise((resolve, reject) => {
setTimeout(resolve, 2000, "two");
});
var p3 = new Promise((resolve, reject) => {
setTimeout(resolve, 3000, "three");
});
var p4 = new Promise((resolve, reject) => {
setTimeout(resolve, 4000, "four");
});
var p5 = new Promise((resolve, reject) => {
reject("reject");
});
Promise.all([p1, p2, p3, p4, p5]).then(values => {
console.log(values);
}, reason => {
console.log(reason)
});
//From console:
//"reject"
// Evenly, it's possible to use .catch
Promise.all([p1, p2, p3, p4, p5]).then(values => {
console.log(values);
}).catch(reason => {
console.log(reason)
});
//From console:
//"reject"
how to use promise.all
const contentPromise = requestUser();
const commentsPromise = requestComments();
const combinedContent = Promise.all([contentPromise, commentsPromise])
.then(([content, comments]) => {
// content and comments have both finished loading.
})
promise.all in javascript
const video1 = new Promise((resolve, reject) => {
resolve("video1 loaded");
});
const video2 = new Promise((resolve, reject) => {
resolve("Video2 loaded");
});
const video3 = new Promise((resolve, reject) => {
resolve("video3 loaded");
});
Promise.all([video1, video2, video3]).then((messages) => {
console.log("messages", messages);
});
javascript Promise.all()
var p1 = Promise.resolve(3);
var p2 = 1337;
var p3 = new Promise((resolve, reject) => {
setTimeout(resolve, 100, "foo");
});
Promise.all([p1, p2, p3]).then(values => {
console.log(values); // [3, 1337, "foo"]
});
promise.all
var p1 = Promise.resolve(3);
var p2 = 1337;
var p3 = new Promise((resolve, reject) => {
setTimeout(() => {
resolve("foo");
}, 100);
});
Promise.all([p1, p2, p3]).then(values => {
console.log(values); // [3, 1337, "foo"]
});
promise all in promise all
var arr = [
{subarr: [1,2,3]},
{subarr: [4,5,6]},
{subarr: [7,8,9]}
];
function processAsync(n) {
return new Promise(function(resolve) {
setTimeout(
function() { resolve(n * n); },
Math.random() * 1e3
);
});
}
Promise.all(arr.map(function(entity){
return Promise.all(entity.subarr.map(function(item){
return processAsync(item);
}));
})).then(function(data) {
console.log(data);
});
promise all
var p1 = Promise.resolve(3);
var p2 = 1337;
var p3 = new Promise((resolve, reject) => {
setTimeout(resolve, 100, "foo");
});
const iterable = [p1, p2, p3];
Promise.all(iterable)