JavaScript: Create an array of elements, ungrouping the elements in an array produced by zip and applying the provided function

JavaScript fundamental (ES6 Syntax): Exercise-106 with Solution

Ungroup Array with Function

Write a JavaScript program to create an array of elements, ungrouping the elements in an array produced by zip and applying the provided function.

• Use Math.max(), Function.prototype.apply() to get the longest subarray in the array, Array.prototype.map() to make each element an array.
• Use Array.prototype.reduce() and Array.prototype.forEach() to map grouped values to individual arrays.
• Use Array.prototype.map() and the spread operator (...) to apply fn to each individual group of elements.

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2

// Define a function 'unzipWith' to unzip an array of arrays and apply a function to each corresponding element.
const unzipWith = (arr, fn) =>
  // Reduce the input array 'arr' to unzip the arrays and apply the function 'fn'.
  arr.reduce(
    // For each value in the array 'arr', update the accumulator 'acc'.
    (acc, val) => (
      // For each value 'v' in 'val', push it to the corresponding array in 'acc'.
      val.forEach((v, i) => acc[i].push(v)),
      // Return the updated accumulator.
      acc
    ),
    // Initialize the accumulator as an array of arrays with lengths equal to the maximum length of the input arrays.
    Array.from({
      length: Math.max(...arr.map(x => x.length))
    }).map(x => [])
  )
  // Map over each array in the unzipped arrays and apply the function 'fn' to their elements.
  .map(val => fn(...val));

// Test the 'unzipWith' function with an example.
console.log(unzipWith([[1, 10, 100], [2, 20, 200]], (...args) => args.reduce((acc, v) => acc + v, 0))); // Output: [3, 30, 300]

Output:

[3,30,300]

Visual Presentation:

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-106-1 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript program that takes a nested array produced by a zip function and flattens it using a provided ungrouping function.
• Write a JavaScript function that reverses the grouping of an array of arrays, returning a single flattened array.
• Write a JavaScript program that applies a mapping function to ungroup elements from a nested array into a single-level array.

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