Foreword
Go language provides a mapping between container map, its internal 散列表（hash）implementation. Similar dictionary in Python.
The basic operation and define a map
package main
import "fmt"
func main() {
// define a map variable, key is sring type, value is of type int
var m1 map[string]int
fmt.Println (m1 == nil) // not initialized (no open space in memory)
// Initialization: a good map of the estimated capacity expansion during the run to avoid
m1 = make(map[string]int, 10)
m1 [ "Age"] = 18
fmt.Println(m1)
fmt.Println (m1 [ "Age"])
// Get the key does not exist
v, ok := m1["姓名"]
if !ok {
fmt.Println ( "not the key")
} else {
fmt.Println (v)
}
// direct access key does not exist, and returns the default value of the corresponding type
fmt.Println (m1 [ "does not exist in the key"])
// traverse the map of the key and value
m2 := make(map[string]string, 10)
m2["姓名"] = "Martin"
m2 [ "sex"] = "male"
for k, v := range m2 {
fmt.Println (k, v)
}
// traverse only map the keys
for k := range m2 {
fmt.Println (k)
}
// traverse the only map of values
for _, v := range m2 {
fmt.Println (v)
}
// delete the key map
delete (m2, "name")
fmt.Println(m2)
// delete the map does not exist in the key () no-option
delete (m1, "the absence of key")
/*
go doc builtin.delete view the built-in functions usage
func delete(m map[Type]Type1, key Type)
The delete built-in function deletes the element with the specified key
(m[key]) from the map. If m is nil or there is no such element, delete is a
Now-on.
*/
}