package map_test import ( "encoding/json" "fmt" "testing" ) func TestKey(t *testing.T) { // type ss []string // mm := map[*ss]string{} } func TestNoOrderMap(t *testing.T) { mm := map[string]string{} mm["m"] = "m" mm["a"] = "a" mm["p"] = "p" mm["o"] = "o" mm["r"] = "r" mm["d"] = "d" // map 无序 for k := range mm { println(k) } // json.Marshal 固定key顺序 bs, _ := json.Marshal(mm) println(string(bs)) } func TestConcurDeleteNotExistKey(t *testing.T) { mm := map[string]string{} for i := 0; i < 10000; i++ { mm[fmt.Sprint(i)] = fmt.Sprint(i) } println("删除不存在的key") for i := 0; i < 10000; i++ { go func() { delete(mm, "") }() } }