Pop

In this medium-level challenge, you'll implement a generic Pop<T> that removes the last element from an array.

type arr1 = ['a', 'b', 'c', 'd']
type arr2 = [3, 2, 1]
 
type re1 = Pop<arr1> // expected to be ['a', 'b', 'c']
type re2 = Pop<arr2> // expected to be [3, 2]

Detailed Explanation

type Pop<T extends unknown[]> = T extends [...infer Keep, infer Last] ? Keep : T

How it works:

• First we constrain the type T to be an array with extends unknown[]
• T extends [...infer Keep, infer Last] matches the array type and collects all elements except the last one into Keep
• ? Keep returns the array type with the last element removed
• we return T if the array is empty