What is the difference between interface and type?

Both describe object shapes. interface can be reopened and extended and is ideal for objects and classes; type is more flexible for unions, primitives, and mapped types.

Generics let you write reusable code parameterized by type, like Array or a function that returns its argument, keeping type safety without hardcoding a type.

What do Partial, Pick, and Omit do?

They are utility types: Partial makes all properties optional, Pick selects keys, and Omit removes keys from a type.

What is the difference between any and unknown?

any disables type checking; unknown is type-safe — you must narrow it before use. Prefer unknown over any.

What is a type guard?

A runtime check (like typeof, instanceof, or a custom is-predicate) that narrows a value to a more specific type within a block.

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Reference

TypeScript Cheat Sheet

Essential TypeScript — types, interfaces, generics, utility types and narrowing. Click any card to copy.