JavaScript: Chain asynchronous functions

JavaScript fundamental (ES6 Syntax): Exercise-62 with Solution

Chain Asynchronous Functions

Write a JavaScript program to chain asynchronous functions.

Note: Loop through an array of functions containing asynchronous events, calling next when each asynchronous event has completed.

• Loop through an array of functions containing asynchronous events, calling next when each asynchronous event has completed.

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2
// Define a function 'chainAsync' to execute an array of asynchronous functions sequentially.
const chainAsync = fns => {
  let curr = 0;
  
  // Define a helper function 'next' to execute the next function in the array.
  const next = () => fns[curr++](next);
  
  // Start the chain by calling 'next'.
  next();
};

// Call 'chainAsync' with an array of asynchronous functions.
chainAsync([
  next => {
    console.log('0 seconds');
    setTimeout(next, 1000);
  },
  next => {
    console.log('1 second');
  }
]);

Output:

0 seconds
1 second

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-62-1 by w3resource (@w3resource) on CodePen.

Improve this sample solution and post your code through Disqus

Previous: Write a JavaScript program to cast the provided value as an array if it's not one.
Next: Write a JavaScript program to clone a given regular expression.