JavaScript: Create an array of elements, grouped based on the position in the original arrays

JavaScript fundamental (ES6 Syntax): Exercise-102 with Solution

Group Array Elements by Position

Write a JavaScript program to create an array of elements, grouped based on the position in the original array.

• Use Math.max(), Function.prototype.apply() to get the longest array in the arguments.
• Create an array with that length as return value and use Array.from() with a mapping function to create an array of grouped elements.
• If lengths of the argument arrays vary, undefined is used where no value could be found.

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2
// Define the 'zip' function to zip arrays together.
const zip = (...arrays) => {
  // Find the maximum length among the input arrays.
  const maxLength = Math.max(...arrays.map(x => x.length));
  // Use Array.from with a length equal to the maxLength to create the zipped array.
  return Array.from({ length: maxLength }, (_, i) => {
    // For each index 'i', map over the 'arrays' to extract the value at index 'i' for each array.
    return arrays.map(arr => arr[i]);
  });
};

// Test the 'zip' function with different arrays.
console.log(zip(['a', 'b'], [1, 2], [true, false]));  
console.log(zip(['a'], [1, 2], [true, false]));  

Output:

[["a",1,true],["b",2,false]]
[["a",1,true],[null,2,false]]

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-102-1 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript program that groups elements of an array based on their index positions, returning an array of groups.
• Write a JavaScript function that splits an array into subarrays where each subarray contains elements from the same positions across multiple arrays.
• Write a JavaScript program that reorganizes an array into a two-dimensional array by grouping elements with the same index modulo a given number.

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