遍历映射的所有键

huangapple
go评论137阅读模式
英文:

Iterating over all the keys of a map

问题

有没有办法获取Go语言地图中所有键的列表？元素的数量可以通过len()函数获得，但如果我有一个地图，像这样：

  1. m := map[string]string{ "key1":"val1", "key2":"val2" };

我如何遍历所有的键？

英文:

Is there a way to get a list of all the keys in a Go language map? The number of elements is given by len(), but if I have a map like:

  1. m := map[string]string{ "key1":"val1", "key2":"val2" };

How do I iterate over all the keys?

答案1

得分: 734

https://play.golang.org/p/JGZ7mN0-U-

  1. for k, v := range m { 
  2.     fmt.Printf("key[%s] value[%s]\n", k, v)
  3. }

或者

  1. for k := range m {
  2.     fmt.Printf("key[%s] value[%s]\n", k, m[k])
  3. }

Go语言for语句的规范指定第一个值是键，第二个变量是值，但不一定要存在。

英文:

https://play.golang.org/p/JGZ7mN0-U-

  1. for k, v := range m { 
  2.     fmt.Printf("key[%s] value[%s]\n", k, v)
  3. }

or

  1. for k := range m {
  2.     fmt.Printf("key[%s] value[%s]\n", k, m[k])
  3. }

Go language specs for for statements specifies that the first value is the key, the second variable is the value, but doesn't have to be present.

答案2

得分: 21

这是一种获取地图键的简单方法。

  1. // 返回给定地图的键
  2. func Keys(m map[string]interface{}) (keys []string) {
  3.     for k := range m {
  4.         keys = append(keys, k)
  5.     }
  6.     return keys
  7. }
  9. // 使用 `Keys` 函数
  10. func main() {
  11.     m := map[string]interface{}{
  12.         "foo": 1,
  13.         "bar": true,
  14.         "baz": "baz",
  15.     }
  16.     fmt.Println(Keys(m)) // [foo bar baz]
  17. }
英文:

Here's some easy way to get slice of the map-keys.

  1. // Return keys of the given map
  2. func Keys(m map[string]interface{}) (keys []string) {
  3. 	for k := range m {
  4. 		keys = append(keys, k)
  5. 	}
  6. 	return keys
  7. }
  9. // use `Keys` func
  10. func main() {
  11. 	m := map[string]interface{}{
  12. 		"foo": 1,
  13. 		"bar": true,
  14. 		"baz": "baz",
  15. 	}
  16. 	fmt.Println(Keys(m)) // [foo bar baz]
  17. }

答案3

得分: 19

有没有办法获取Go语言中map的所有键的列表？

  1. ks := reflect.ValueOf(m).MapKeys()

如何遍历所有的键？

使用接受的答案：

  1. for _, k := range m { ... }
英文:

> Is there a way to get a list of all the keys in a Go language map?

  1. ks := reflect.ValueOf(m).MapKeys()

> how do I iterate over all the keys?

Use the accepted answer:

  1. for _, k := range m { ... }

答案4

得分: 6

一个类型不可知的解决方案：

  1. for _, key := range reflect.ValueOf(yourMap).MapKeys() {
  2.     value := yourMap.MapIndex(key).Interface()
  3.     fmt.Println("键：", key, "值：", value)
  4. }
英文:

A Type agnostic solution:

  1. for _, key := range reflect.ValueOf(yourMap).MapKeys() {
  2.     value := yourMap.MapIndex(key).Interface()
  3.     fmt.Println("Key:", key, "Value:", value)
  4. }

答案5

得分: 4

使用泛型：

  1. func Keys[K comparable, V any](m map[K]V) []K {
  2.     keys := make([]K, 0, len(m))
  4.     for k := range m {
  5.         keys = append(keys, k)
  6.     }
  8.     return keys
  9. }
英文:

Using Generics:

  1. func Keys[K comparable, V any](m map[K]V) []K {
  2.     keys := make([]K, 0, len(m))
  4.     for k := range m {
  5.         keys = append(keys, k)
  6.     }
  8.     return keys
  9. }

答案6

得分: 0

对于map[string]string的排序键。

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"sort"
  6. )
  8. func main() {
  9. 	m := map[string]string{"key1": "val1", "key2": "val2"}
  10. 	sortStringMap(m)
  11. }
  13. // sortStringMap按键排序打印[string]string
  14. func sortStringMap(m map[string]string) {
  15. 	var keys []string
  16. 	for key := range m {
  17. 		keys = append(keys, key)
  18. 	}
  19. 	sort.Strings(keys) // 对键进行排序
  20. 	for _, key := range keys {
  21. 		fmt.Printf("%s\t:%s\n", key, m[key])
  22. 	}
  23. }

输出：

  1. key1    :val1
  2. key2    :val2
英文:

For sorted keys of map[string]string.

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"sort"
  6. )
  8. func main() {
  9. 	m := map[string]string{"key1": "val1", "key2": "val2"}
  10. 	sortStringMap(m)
  11. }
  13. // sortStringMap prints the [string]string as keys sorted
  14. func sortStringMap(m map[string]string) {
  15. 	var keys []string
  16. 	for key := range m {
  17. 		keys = append(keys, key)
  18. 	}
  19. 	sort.Strings(keys)  // sort the keys
  20. 	for _, key := range keys {
  21. 		fmt.Printf("%s\t:%s\n", key, m[key])
  22. 	}
  23. }

output:

  1. key1    :val1
  2. key2    :val2

huangapple
  • 本文由 发表于 2009年12月4日 01:15:18
  • 转载请务必保留本文链接：https://go.coder-hub.com/1841443.html
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