Go Map初始化方式及Map的多层嵌套

package main

import (
	"fmt"
)

func main() {

	//多维map的声明与实现
	//方法1：初始化一个空的多维映射
	mainMapA := map[string]map[string]string{}

	subMapA := map[string]string{"A_Key_1": "A_SubValue_1", "A_key_2": "A_SubValue_2"}
	mainMapA["MapA"] = subMapA
	fmt.Println("\nMultityMapA")
	fmt.Println("mainMapA[\"MapA\"]", mainMapA["MapA"])
	//输出：mainMapA["MapA"] map[A_Key_1:A_SubValue_1 A_key_2:A_SubValue_2]
	fmt.Println("mainMapA", mainMapA)
	//输出：mainMapA map[MapA:map[A_Key_1:A_SubValue_1 A_key_2:A_SubValue_2]]
	for keyA, valA := range mainMapA {
		fmt.Printf("keyA:%s  val:%s\n", keyA, valA)
		//输出：keyA:MapA  val:map[A_Key_1:A_SubValue_1 A_key_2:A_SubValue_2]
		for subKeyA, subValA := range valA {
			fmt.Printf("mapName=%s	Key=%s	Value=%s\n", keyA, subKeyA, subValA)
			//mapName=MapA	Key=A_Key_1	Value=A_SubValue_1
			//mapName=MapA	Key=A_key_2	Value=A_SubValue_2
		}
	}

	//方法2 使用make声明一个多维映射(等同一般声明)
	//var mainMap map[string]map[string]string
	mainMap := make(map[string]map[string]string)

	subMap := make(map[string]string)

	subMap["key_1"] = "SubValue_1"
	subMap["key_2"] = "SubValue_2"

	mainMap["Map"] = subMap
	fmt.Println("\nMultityMap")

	for key, val := range mainMap {
		for subkey, subval := range val {
			fmt.Printf("mapName=%s	Key=%s	Value=%s\n", key, subkey, subval)
		}
	}

	//方法3 使用interface初始化一个一维映射
	//关键点：interface{}可以代表任意类型
	//原理知识点interface{}就是一个空接口，所有类型都实现了这个接口，所以可以代表所有类型

	//mainMapC :=make(map[string]interface{})

	mainMapC := map[string]interface{}{}

	subMapC := make(map[string]string)

	subMapC["C_key_1"] = "C_SubValue_1"
	subMapC["C_key_2"] = "C_SubValue_2"

	mainMapC["MapC"] = subMapC

	fmt.Println("\nMutityMpc")

	for keyC, valC := range mainMapC {
		fmt.Println("keyC", keyC)
		fmt.Println("valC", valC)
		//此处必须实例化接口类型，即*.(map[string]string)
		//实例化：是将一个抽象的概念类，具体到该类的实物过程
		//c := valC.(map[string]string)
		for subKeyC, subValC := range valC.(map[string]string) {
			fmt.Printf("mapName=%s	Key=%s	Value=%s\n", keyC, subKeyC, subValC)

		}
	}

	//附加方法值为任何类型：
	mainMapD := map[string]map[string]interface{}{}

	subMapD := make(map[string]interface{})

	subMapD["D_key_1"] = "C_SubValue_1"
	subMapD["D_key_2"] = 111

	mainMapD["MapD"] = subMapD

	fmt.Println("\nMutityMpD")

	for keyD, valD := range mainMapD {
		fmt.Println("keyD", keyD)
		fmt.Println("valD", valD)
		for subKeyD, subvalD := range valD {
			fmt.Printf("mapName=%s Key=%s Value=%s\n", keyD, subKeyD, subvalD)
		}
	}

	//附加方法


	mainMapE := map[string]interface{}{}

	subMapE := make(map[string]interface{})

	subMapE["C_key_1"] = "C_SubValue_1"
	subMapE["C_key_2"] = 222

	mainMapE["MapC"] = subMapE

	fmt.Println("\nMutityMpE")

	for keyE, valE := range mainMapE {
		fmt.Println("keyC", keyE)
		fmt.Println("valC", valE)
		//此处必须实例化接口类型，即*.(map[string]string)
		//实例化：是将一个抽象的概念类，具体到该类的实物过程
		//c := valC.(map[string]string)
		for subKeyE, subValE := range valE.(map[string]interface{}) {
			fmt.Printf("mapName=%s Key=%s Value=%s\n", keyE, subKeyE, subValE)

		}
	}

}