Arrays

Summary

Ordered, index-based collections with a rich built-in method set (`map`, `filter`, `reduce`, etc.) that's essential for everyday data transformation in JS. Arrays are frequently combined with higher-order methods to transform, search, group, validate, and aggregate application data without manually managing indexes.

• 1Rewrite a `for` loop that transforms data using `.map()` instead. Validate your understanding by applying it in a small practical example.
• 2Practice destructuring arrays and using the spread operator to copy/merge them. Test it with at least one normal case and one edge case so you can explain the behavior confidently.
• 3Learn `.find()`, `.some()` and `.every()` for common search patterns.