var sliceOfInt []int
var sliceOfString []int
var sliceOfUser []User
var sliceOfMap []map[string]int

letters := []string{"a", "b", "c", "d"}
numbers := []string{1, 2, 3, 4, 5}
numbers := []User{ User{ Name: "Thuc"}, User{Name: "Mr Vu"} }