Utility TypesBeginner
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typescriptWhat are essential TypeScript Utility Types (Partial, Pick, Omit, Record)?
Explanation & Concept
TypeScript includes built-in utility types to transform existing types without duplication:
• `Partial<T>`: Makes all properties in T optional. • `Required<T>`: Makes all properties in T mandatory. • `Pick<T, K>`: Selects a subset of keys K from T. • `Omit<T, K>`: Removes keys K from T. • `Record<K, T>`: Constructs an object type whose property keys are K and values are T.
Code Example
typescript
interface Article {
id: string;
title: string;
content: string;
authorId: string;
publishedAt: Date;
}
// Omit 'id' and 'publishedAt' for creation payload
type CreateArticleDTO = Omit<Article, "id" | "publishedAt">;
// Partial for update mutations
type UpdateArticleDTO = Partial<CreateArticleDTO>;
// Record for dictionary mapping
type ArticleCache = Record<string, Article>;How It Works & Key Takeaways
Using utility types keeps your codebase DRY by deriving mutation, creation, and cache shapes from a single source of truth.
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