36 lines
627 B
Markdown
36 lines
627 B
Markdown
---
|
|
title: chainAsync
|
|
tags: function,intermediate
|
|
---
|
|
|
|
Chains asynchronous functions.
|
|
|
|
Loop through an array of functions containing asynchronous events, calling `next` when each asynchronous event has completed.
|
|
|
|
```js
|
|
const chainAsync = fns => {
|
|
let curr = 0;
|
|
const last = fns[fns.length - 1];
|
|
const next = () => {
|
|
const fn = fns[curr++];
|
|
fn === last ? fn() : fn(next);
|
|
};
|
|
next();
|
|
};
|
|
```
|
|
|
|
```js
|
|
chainAsync([
|
|
next => {
|
|
console.log('0 seconds');
|
|
setTimeout(next, 1000);
|
|
},
|
|
next => {
|
|
console.log('1 second');
|
|
setTimeout(next, 1000);
|
|
},
|
|
() => {
|
|
console.log('2 second');
|
|
}
|
|
]);
|
|
``` |