Use Array.reduce() for Powerful Transformations

Problem

Complex array transformations require multiple passes and intermediate variables.

Solution

Use Array.reduce() to transform arrays into any shape (sum, object, grouped data).

Benefit

Single-pass solution that handles complex transformations efficiently.

Code Example

const numbers = [1, 2, 3, 4, 5];

// Sum array
const sum = numbers.reduce((acc, n) => acc + n, 0);

// Group by property
const grouped = items.reduce((acc, item) => {
    acc[item.category] = acc[item.category] || [];
    acc[item.category].push(item);
    return acc;
}, {});