JavaScript: Group the elements into two arrays, depending on the provided function's truthiness for each element

JavaScript fundamental (ES6 Syntax): Exercise-168 with Solution

Write a JavaScript program to group the elements into two arrays, depending on the provided function's truthiness for each element.

• Use Array.prototype.reduce() to create an array of two arrays.
• Use Array.prototype.push() to add elements for which fn returns true to the first array and elements for which fn returns false to the second one.

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2 
const partition = (arr, fn) =>
  arr.reduce(
    (acc, val, i, arr) => {
      acc[fn(val, i, arr) ? 0 : 1].push(val);
      return acc;
    },
    [[], []]
  );
const users = [{ user: 'barney', age: 36, active: false }, { user: 'fred', age: 40, active: true }];
partition(users, o => o.active);
console.log(users);

Sample Output:

[{"user":"barney","age":36,"active":false},{"user":"fred","age":40,"active":true}]

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-168-1 by w3resource (@w3resource) on CodePen.

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