key-value的数据结构，又叫字典或关联数组
var map1 map[keytype]valuetype var a map[string]string var a map[string]int var a map[int]string var a map[string]map[string]string
备注：声明是不会分配内存的，初始化需要make
样例一：
func testMap() {
var a map[string]string
a = make(map[string]string, 10)
a["abc"] = "efg"
a["abc"] = "efg"
a["abc1"] = "efg"
fmt.Println(a)
}
样例二：
func testMap() {
a := make(map[string]string, 10)
a["abc"] = "efg"
a["abc"] = "efg"
a["abc1"] = "efg"
fmt.Println(a)
}
样例三：
func testMap() {
var a map[string]string = map[string]string{
"key": "value",
}
a["abc"] = "efg"
a["abc"] = "efg"
a["abc1"] = "efg"
fmt.Println(a)
}
var a map[string]string = map[string]string{“hello”: “world”}
a = make(map[string]string, 10)
插入和更新：a[“hello”] = “world”
查找：Val, ok := a[“hello”]
遍历：
for k, v := range a {
fmt.Println(k,v)
}
删除：delete(a, “hello”)
长度：len(a)
func trans(a map[string]map[string]string) {
for k, v := range a {
fmt.Println(k)
for k1, v1 := range v {
fmt.Println("\t", k1, v1)
}
}
}
func testMap4() {
a := make(map[string]map[string]string, 100)
a["key1"] = make(map[string]string)
a["key1"]["key2"] = "abc"
a["key1"]["key3"] = "abc"
a["key1"]["key4"] = "abc"
a["key1"]["key5"] = "abc"
a["key2"] = make(map[string]string)
a["key2"]["key2"] = "abc"
a["key2"]["key3"] = "abc"
trans(a)
delete(a, "key1")
fmt.Println()
trans(a)
fmt.Println(len(a))
}
func testMap2() {
a := make(map[string]map[string]string, 100)
a["key1"] = make(map[string]string)
a["key1"]["key2"] = "abc"
a["key1"]["key3"] = "abc"
a["key1"]["key4"] = "abc"
a["key1"]["key5"] = "abc"
fmt.Println(a)
}
func testMap5() {
var a []map[int]int
a = make([]map[int]int, 5)
if a[0] == nil {
a[0] = make(map[int]int)
}
a[0][10] = 10
fmt.Println(a)
}
原文：http://www.cnblogs.com/shhnwangjian/p/7446995.html