JS Practice — Built-in Objects

Generics — head<T>

📖 Usage Example

function head<T>(arr: T[]): T | undefined { return arr[0] }
head([1, 2, 3])   // → 1
head([])          // → undefined

head<T> returns the first element, preserving the array element type via generic inference.

Generics: head<T>

Challenge: Implement head<T>(arr: T[]): T | undefined returning the first element, or undefined for empty arrays.

head([1, 2, 3])  // → 1
head([])         // → undefined

💡 Hints (1)