#00016 pop

[pkc918]

question

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]

implement pop, return an Array without it's last element

resolve

type Pop<T extends any[]> = T extends [...infer Prev, infer _] ? Prev : []

explain

直接通过使用 infer 变量来接受元组中的参数，... 表示多个，和js中解构类似，过滤出最后一个值就行了