TypeScript Uppercase<StringType> template literal type transforms the characters of StringType to uppercase, ensuring that any string value assigned to it is represented in all uppercase letters.

Syntax:

type Geek= Uppercase<GFG>

Parameters:

• StringType: It is the input string or string literal type you want to convert to uppercase.
• Uppercase<StringType>: transforms all characters in StringType to uppercase, returning the resulting uppercase string type.

Example 1: This example showcases how to convert a lowercase string to uppercase using the Uppercase<StringType> Template Literal in TypeScript, allowing the creation of a constant with the string entirely in uppercase characters.

Output:

GEEKSFORGEEKS

Example 2: In this example, we define a type symbol with possible values “alpha,” “beta,” or “gamma.” It then creates a type geek by converting these values to uppercase. The result variable is assigned “ALPHA” and logs it to the console.

Output:

ALPHA

Reference: https://www.typescriptlang.org/docs/handbook/2/template-literal-types.html#uppercasestringtype