Alias the Callback

Function type expressions can also be aliased. Giving a name to a callback shape makes code easier to read and reuse. Keep parameter and return types explicit.

• Name a function type for clarity (e.g., (n: number) => string).
• Map an array without mutating the original.
• Return a new array of formatted strings.

Your Task

1. Define type Stringifier = (n: number) => string.
2. Implement formatAll(nums: number[], fmt: Stringifier): string[] that maps each number using fmt.