test/map/map_test.go

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, "")
		}()
	}
}