The Lowercase
utility type converts an entire string to lowercase.
Structure
Lowercase<StringType>
Example
type Greeting = 'Hello' | 'Hi'
type Name = 'Ahmad' | 'Bilal';
type LowercaseGreetingAndName = Lowercase<`${Greeting} ${Name}`>; //"hello ahmad" | "hello bilal" | "hi ahmad" | "hi bilal"