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Arrays
6 exercises
Arrays are ordered lists of values written as T[] or Array<T>:
const numbers: number[] = [1, 2, 3];
const users: User[] = [{ id: 1, name: "Alice" }];Now that you can model a single object, it's natural to work with arrays of objects like User[] or Product[].
In this category, you'll:
- Work with arrays of primitives (summing and filtering numbers)
- Transform arrays of objects (plucking fields, filtering by property)
- Use methods like
.map(),.filter(), and.find()with proper types - Return precise types like
T | undefinedfrom.find() - Make immutable updates without mutating inputs
By the end, you'll be comfortable writing small, typed helpers that transform arrays safely and predictably.