TypeScript Mapped Types

Transform existing object types into new structures programmatically.

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Mapped types build on the syntax for index signatures. They iterate through keys using [K in keyof T] to create modified variations of existing interfaces.

Key Takeaways: TypeScript Mapped Types

Mastering TypeScript Mapped Types helps you write clean and reliable TypeScript code. Follow standard conventions, test edge cases, and keep logic simple. Try running the code example below and complete the exercises to build confidence.

TypeScript Mapped Types Code Example

TypeScript

type Permissions = "read" | "write" | "delete";

type RoleAccess = {
  [K in Permissions]: boolean;
};

const admin: RoleAccess = { read: true, write: true, delete: true };
console.log("Admin can delete:", admin.delete);

Output

Admin can delete: true

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TypeScript Mapped Types

💡 Key Takeaways: TypeScript Mapped Types

TypeScript Mapped Types Code Example

Key Takeaways: TypeScript Mapped Types