英文:
How can I initialize a nested map inside a struct in Go?
问题
如果我有一个嵌套的映射变量，像这样在一个结构体内：
type someStruct struct {nestedMap map[int]map[string]string}var ss = someStruct {nestedMap: make(map[int]map[string]string),}
这样做会导致运行时错误。
我该如何初始化它？
英文:
If I have a nested map variable like this inside a struct:
type someStruct struct {nestedMap map[int]map[string]string}var ss = someStruct {nestedMap: make(map[int]map[string]string),}
This does not work and does a runtime error.
How do I initialize it?
答案1
得分: 7
你必须也要创建子地图。
func (s *someStruct) Set(i int, k, v string) {child, ok := s.nestedMap[i]if !ok {child = map[string]string{}s.nestedMap[i] = child}child[k] = v}
英文:
You have to make the child maps as well.
func (s *someStruct) Set(i int, k, v string) {child, ok := s.nestedMap[i]if !ok {child = map[string]string{}s.nestedMap[i] = child}child[k] = v}
答案2
得分: 1
初始化嵌套的映射可以像这样进行：
temp := make(map[string]string, 1)temp["name"] = "Kube"ss.nestedMap[2] = tempfmt.Println(ss)
请注意，这只是一个示例代码，ss 是一个包含嵌套映射的结构体或变量。
英文:
Initilize nested map like this:
temp := make(map[string]string,1)temp ["name"]="Kube"ss.nestedMap [2] = tempfmt.Println(ss)
答案3
得分: 1
虽然接受的答案是正确的，但我发现在我迄今遇到的所有情况中，我只需创建一个复杂的键而不是嵌套的映射。
type key struct {intKey intstrKey string}然后只需在一行中初始化映射：m := make(map[key]string)
英文:
While the accespted answer is true, what I've found is that in all situations I've had so far I could just create a complex key instead of nested map.
type key struct {intKey intstrKey string}
Then just initiate the map in one line:
m := make(map[key]string)
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