To convert a string literal type into an uppercase format, you can use the built-in Uppercase type that comes with TypeScript.
TL;DR
// lowercase string literal type
type Greeting = "hello";
// convert string literal type
// into uppercase format
type GreetingUppercase = Uppercase<Greeting>; // HELLO
For example, let's say we have a string literal type that is in the lowercase format like this,
// lowercase string literal type
type Greeting = "hello";
Now to convert the string literal type into uppercase let's use the Uppercase built-in type and pass the Greeting type into it using the angled bracket (<>) syntax.
It can be done like this,
// lowercase string literal type
type Greeting = "hello";
// convert string literal type
// into uppercase format
type GreetingUppercase = Uppercase<Greeting>; // HELLO
Now if you hover over the GreetingUppercase type you can see that the hello string literal type is now converted into an uppercase format. Yay 🥳.
See the above code live in codesandbox.
That's all 😃!
