Predefined Conditional Types

In TypeScript, Predefined Conditional Types are built-in conditional types provided by the language. They are designed to perform common type transformations based on the characteristics of a given type.

Exclude<UnionType, ExcludedType>: This type removes all the types from Type that are assignable to ExcludedType.

Extract<Type, Union>: This type extracts all the types from Union that are assignable to Type.

NonNullable<Type>: This type removes null and undefined from Type.

ReturnType<Type>: This type extracts the return type of a function Type.

Parameters<Type>: This type extracts the parameter types of a function Type.

Required<Type>: This type makes all properties in Type required.

Partial<Type>: This type makes all properties in Type optional.

Readonly<Type>: This type makes all properties in Type readonly.