2021-05-20

 1package main
 2
 3import "fmt"
 4
 5var testMap = map[string]map[string]struct {
 6	Name string
 7}{
 8	"first":  {"second": {Name: "12312"}},
 9	"second": {"second": {"12312"}},
10}
11
12func main() {
13	d := testMap["first"]["second"].Name
14	fmt.Printf("++-%v-++\n", d)
15  
16  
17  // map 不会报 nil
18	c := testMap["first22"]["second"].Name
19	fmt.Printf("++-%v-++\n", c)
20}

1++-12312-++
2++--++