TypeScript Advanced Types You Need to Know

TypeScript's type system is incredibly powerful. This guide covers advanced type features that will make your code more type-safe and maintainable.

Conditional Types

Conditional types allow you to create types that depend on other types.

type NonNullable = T extends null | undefined ? never : T;

Mapped Types

Mapped types let you create new types by transforming properties of existing types.

type Readonly = {

readonly [P in keyof T]: T[P];

};

Template Literal Types

Template literal types enable string manipulation at the type level.

type EventName = on${Capitalize};

Utility Types

TypeScript provides several built-in utility types:

Advanced Patterns

Branded Types

Create distinct types from primitives:

type UserId = string & { __brand: 'UserId' };

Discriminated Unions

Use discriminated unions for type-safe state management.

Best Practices

Conclusion

Mastering advanced TypeScript types will make you a more effective developer and help you write more robust code.