09. sort

arr := []int{3, 1, 4}
sort.Ints(arr)

sort.Slice(arr, func(i, j int) bool {
    return arr[i] > arr[j]
})

type Person struct {
    Name string
    Age  int
}
people := []Person{{"Bob", 31}, {"Alice", 25}}
sort.Slice(people, func(i, j int) bool {
    return people[i].Age < people[j].Age // 按年龄升序
})