Map

// 先声明map
var m1 map[string]string
// 再使用make函数创建一个非nil的map，nil map不能赋值
m1 = make(map[string]string)
// 最后给已声明的map赋值
m1["a"] = "aa"
m1["b"] = "bb"

// 直接创建
m2 := make(map[string]string)
// 然后赋值
m2["a"] = "aa"
m2["b"] = "bb"

// 初始化 + 赋值一体化
m3 := map[string]string{
    "a": "aa",
    "b": "bb",
}

if v, ok := m1["a"]; ok {
    fmt.Println(v)
} else {
    fmt.Println("Key Not Found")
}

for k, v := range m1 {
    fmt.Println(k, v)
}

scene := make(map[string]int)

// 准备map数据
scene["route"] = 66
scene["brazil"] = 4
scene["china"] = 960

delete(scene, "brazil")

for k, v := range scene {
    fmt.Println(k, v)
}
//route 66
//china 960

type SafeMap struct {
    Data map[string]interface{}
    Lock sync.RWMutex
}
 
func (this *SafeMap) Get(k string) interface{} {
    this.Lock.RLock()
    defer this.Lock.RUnlock()
    if v, exit := this.Data[k]; exit {
        return v
    }
    return nil
}
 
func (this *SafeMap) Set(k string, v interface{}) {
    this.Lock.Lock()
    defer this.Lock.Unlock()
    if this.Data == nil {
        this.Data = make(map[string]interface{})
    }
    this.Data[k] = v
}

var test sync.Map
 
//设置元素
func set (k,v interface{}){
    test.Store(k,v)
}
 
//获得元素
func get (k interface{}) interface{}{
    tem ,exit := test.Load(k)
    if exit {
        return tem
    }
    return nil
}
 
//传入一个 函数 ，sync.map  会内部迭代 ，运行这个函数
func ranggfunc (funcs func(key, value interface{}) bool) {
    test.Range(funcs)
}
 
//删除元素
func del(key interface{}){
    test.Delete(key)
}