Disclosure
Most of the problems under my TypeHero Challenges folder were either obtained from typehero.dev or from type-challenges repo. Purpose of these articles are just to document my approaches for my easy reference. Please visit the respective links for more info.
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Problem Description
Implement Capitalize<T> which converts the first letter of a string to uppercase and leave the rest as-is.
For example:
type capitalized = Capitalize<'hello world'> // expected to be 'Hello world'Solutions
Approach 1: Using Uppercase built-in utility type
type MyCapitalize<S extends string> = S extends `${infer FirstLetter}${infer Rest}` ? `${Uppercase<FirstLetter>}${Rest}` : S;