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} 结果
1++-12312-++ 2++--++