英文:
Idiomatic else if chain for a map key
问题
我有一个相当长的else if链，用于在映射中查找键并设置特定的值（如果找到）。我选择用最少的代码来实现，代码如下（m是一个map[string]interface{}）：
var ok bool
var s interface{}
if s, ok = m["key1"]; ok {
} else if s, ok = m["key2"]; ok {
....
} else if s, ok = m["keyN"]; ok {
} else {
return RuhRohError
}
g.Id = s.(string)
这种方式感觉有点笨拙，我在条件语句中使用了这么多的else if来设置一个变量。有没有一种惯用的方法来做到这一点？我觉得这种方式不会立即清楚我想要做什么。
英文:
I have a fairly long else if chain looking for keys in a map and setting a specific value if found. The way I chose to do it with the least amount of code was this (m is a map[string]interface{})
var ok bool
var s interface{}
if s, ok = m["key1"]; ok {
} else if s, ok = m["key2"]; ok {
....
} else if s, ok = m["keyN"]; ok {
} else {
return RuhRohError
}
g.Id = s.(string)
This feels kinda clunky, I am doing all of these else if's to set a variable in the condition. Is there an idiomatic way to do this? I think this way doesn't make it immediately obvious what I am trying to do.
答案1
得分: 2
例如，
package main
import "fmt"
func findValue(m map[string]interface{}, keys []string) (interface{}, bool) {
for _, key := range keys {
if value, ok := m[key]; ok {
return value, true
}
}
return nil, false
}
func main() {
m := map[string]interface{}{"keyn": "valuen"}
keys := []string{"key1", "key2", "keyn"}
s, found := findValue(m, keys)
if !found {
return
}
id := s.(string)
fmt.Println(id)
}
输出：
valuen
英文:
For example,
package main
import "fmt"
func findValue(m map[string]interface{}, keys []string) (interface{}, bool) {
for _, key := range keys {
if value, ok := m[key]; ok {
return value, true
}
}
return nil, false
}
func main() {
m := map[string]interface{}{"keyn": "valuen"}
keys := []string{"key1", "key2", "keyn"}
s, found := findValue(m, keys)
if !found {
return
}
id := s.(string)
fmt.Println(id)
}
Output:
valuen
答案2
得分: 1
实际上，我认为你提供的代码非常容易阅读和理解。它有点啰嗦，但没有什么神奇的东西；）。所以如果只有一个地方需要编写这段代码，我会保持原样。如果你需要多次编写它，我会考虑编写另一个评论中提到的findValue函数。
英文:
Actually I think the code you provided is very easy to read and understand. It is a bit verbose but there is no magic ;). So if there is only one place where you have to write this code I would leave it as it is. If you need to write it a few times I would consider writing findValue function mentioned in another comment.
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