w3resource

JavaScript: Execute a provided function once for each array element, starting from the array's last element

JavaScript fundamental (ES6 Syntax): Exercise-76 with Solution

Write a JavaScript program to execute a provided function once for each array element, starting from the array's last element.

  • Use Array.prototype.slice() to clone the given array and Array.prototype.reverse() to reverse it.
  • Use Array.prototype.forEach() to iterate over the reversed array.

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2 
const forEachRight = (arr, callback) =>
  arr
    .slice(0)
    .reverse()
    .forEach(callback);
forEachRight([1, 2, 3, 4], val => console.log(val));

Sample Output:

4
3
2
1

Flowchart:

flowchart: Execute a provided function once for each array element, starting from the array's last element

Live Demo:

See the Pen javascript-basic-exercise-76-1 by w3resource (@w3resource) on CodePen.


Improve this sample solution and post your code through Disqus

Previous: Write a JavaScript program to compute the new ratings between two or more opponents using the Elo rating system
Next: Write a JavaScript program to iterate over all own properties of an object, running a callback for each one.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



JavaScript: Tips of the Day

Chunks an array into n smaller arrays

Example:

const tips_chunkIntoN = (arr, n) => {
  const size = Math.ceil(arr.length / n);
  return Array.from({ length: n }, (v, i) =>
    arr.slice(i * size, i * size + size)
  );
}
console.log(tips_chunkIntoN([1, 2, 3, 4, 5, 6, 7,8], 4)); 

Output:

[[1,2],[3,4],[5,6],[7,8]]