方法一 双重for循环，设置标识，增加到新的切片中，达到去重效果：

func main() {
    var arr = []string{"hello", "hi", "world", "hi", "china", "hello", "hi"}
    fmt.Println(RemoveRepeatedElement(arr))
}
func RemoveRepeatedElement(arr []string) (newArr []string) {
    newArr = make([]string, 0)
    for i := 0; i < len(arr); i++ {
        repeat := false
        for j := i + 1; j < len(arr); j++ {
            if arr[i] == arr[j] {
                repeat = true
                break
            }
        }
        if !repeat {
            newArr = append(newArr, arr[i])
        }
    }
    return
}

方法二： 通过map键的唯一性去重

//第二种写法：更简洁点
func RemoveRepeated(s []int) []int {
    start := time.Now()
    result := []int{}
    m := make(map[int]bool) //map的值不重要
    for _, v := range s {
        if _, ok := m[v]; !ok {
            result = append(result, v)
            m[v] = true
        }
    }
    fmt.Println("花费时间:", fmt.Sprintf("%vms", (time.Now().UnixNano()-start.UnixNano())/1e+6))
    return result
}

//第二种写法： 
var strMap make(map[string]string)
strSlice := []string {"slice","int","string","int","boolean","string"}
for _,v:= range strSlice{
    strMap[v] = v
}
//strMap为：{"slice"："slice","int"："int","string"："string","boolean"：boolean"}
//如果想将map转换为slice，可利用数组的append函数
var secondStr []string
for _,value := range strMap{
    secondStr = append(secondStr ,value)
}
//secondStr为：{"slice","int","string","boolean"}

方法三：利用反射和interface实现， 我有点看不懂

func main() {
  b := []string{"a", "b", "c", "c", "e", "f", "a", "g", "b", "b", "c"}
   sort.Strings(b)
   fmt.Println(Duplicate(b))
   c := []int{1, 1, 2, 4, 6, 7, 8, 4, 3, 2, 5, 6, 6, 8}
   sort.Ints(c)
   fmt.Println(Duplicate(c))
}
func Duplicate(a interface{}) (ret []interface{}) {
   va := reflect.ValueOf(a)
   for i := 0; i < va.Len(); i++ {
      if i > 0 && reflect.DeepEqual(va.Index(i-1).Interface(), va.Index(i).Interface()) {
         continue
      }
      ret = append(ret, va.Index(i).Interface())
   }
   return ret
}