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

Execute Function for Array in Reverse Order

Write a JavaScript program to execute a provided function once for each array element, starting with 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
// Define the function 'forEachRight' to iterate over an array in reverse order and apply a callback function to each element.
const forEachRight = (arr, callback) =>
  // Create a shallow copy of the array, reverse it, and iterate over each element.
  arr
    .slice(0) // Create a shallow copy of the array to avoid mutating the original array.
    .reverse() // Reverse the order of elements in the copied array.
    .forEach(callback); // Apply the callback function to each element.

// Example usage:
forEachRight([1, 2, 3, 4], val => console.log(val)); // Outputs: 4, 3, 2, 1

Output:

4
3
2
1

Flowchart:

Live Demo:

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

For more Practice: Solve these Related Problems:

• Write a JavaScript program that iterates over an array from the last element to the first, applying a provided function.
• Write a JavaScript function that uses a reverse loop to execute a callback on each array element in reverse order.
• Write a JavaScript program that reverses an array and then invokes a function for each element, preserving the original array order.

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