如何在Go中的结构内部初始化嵌套映射？

Question

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?

Answer 1

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
}

<kbd>playground</kbd>