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JavaScript: Chain asynchronous functions

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

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 
const chainAsync = fns => {
  let curr = 0;
  const next = () => fns[curr++](next);
  next();
};
chainAsync([
  next => {
    console.log('0 seconds');
    setTimeout(next, 1000);
  },
  next => {
    console.log('1 second');
  }
]);

Sample Output:

0 seconds
1 second

Flowchart:

flowchart: Chain asynchronous functions

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

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JavaScript: Tips of the Day

Returns an array of n-tuples of consecutive elements

Example:

const tips_arr = (n, arr) =>  n > arr.length ? [] : arr.slice(n - 1).map((v, i) =>[...arr.slice(i, i + n - 1), v]);
console.log(tips_arr(2, [1, 2, 3, 4, 5])); 
console.log(tips_arr(3, [1, 2, 3, 4, 5]));
console.log(tips_arr(5, [1, 2, 3, 4]));

Output:

[[1, 2], [2, 3], [3, 4], [4, 5]]
[[1, 2, 3], [2, 3, 4], [3, 4, 5]]
[]