英文:
Reorder or Scrambling order of elements in slice or map GAE Go
问题
我有一个从数据存储中获取所有问题的代码：
queQ := datastore.NewQuery("Question")
questions := make([]questionData, 0)
if keys, err := queQ.GetAll(c, &questions); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
我想要以随机的方式逐个显示这些问题。我希望在Go（服务器）中重新排序问题切片，而不是在客户端中进行。有什么办法可以打乱切片的顺序吗？我考虑过生成随机数，但我觉得应该有更简单的方法。非常感谢！
英文:
I have a code that get all question from datastore:
queQ := datastore.NewQuery("Question")
questions := make([]questionData, 0)
if keys, err := queQ.GetAll(c, &questions); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
I wanted to display these question one a time but in a random manner. I would like to do the reordering of the question slice in go(server) and not in the client. How could it be possible to scramble the ordering of the slices? I have thought of generating ramdom number but I think there is an easy way to do it. Many thanks to all!
答案1
得分: 2
在你的代码中，keys和questions是数据存储键和值的同步切片。因此，使用随机序列的切片索引来访问questions。例如，要随机选择所有键和值切片，
package main
import (
"fmt"
"math/rand"
"time"
)
type Key struct{}
type Value interface{}
func main() {
keys := make([]*Key, 5)
values := make([]Value, len(keys))
rand.Seed(time.Now().Unix())
for _, r := range rand.Perm(len(keys)) {
k := keys[r]
v := values[r]
fmt.Println(r, k, v)
}
}
输出：
2 <nil> <nil>
3 <nil> <nil>
4 <nil> <nil>
0 <nil> <nil>
1 <nil> <nil>
代码已经修改为使用rand.Perm函数。
英文:
In your code, keys and questions are synchronized slices for the datastore keys and values. Therefore, use a random sequence of slice indices to access questions. For example, to select all the key and value slices randomly,
package main
import (
"fmt"
"math/rand"
"time"
)
type Key struct{}
type Value interface{}
func main() {
keys := make([]*Key, 5)
values := make([]Value, len(keys))
rand.Seed(time.Now().Unix())
for _, r := range rand.Perm(len(keys)) {
k := keys[r]
v := values[r]
fmt.Println(r, k, v)
}
}
Output:
2 <nil> <nil>
3 <nil> <nil>
4 <nil> <nil>
0 <nil> <nil>
1 <nil> <nil>
The code has been revised to use the rand.Perm function.
答案2
得分: 1
也许你可以使用math/rand包
randomQuestion := questions[rand.Intn(len(questions))]
英文:
perhaps you can use package math/rand
randomQuestion:=questions[rand.Intn(len(questions)]
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