golang的字典map

package main

import "fmt"

func main() {
	//make创建map类型

	var  userinfo = make(map[string]string)

	userinfo["name"] = "username"
	userinfo["age"]="age"
	userinfo["sex"]="男"

	fmt.Println(userinfo) //map[name:username age:age sex:男]
	fmt.Println(userinfo["name"])  //username

	//map也支持声明的时候填充元素

	info := map[string]string{
		"name":"username",
		"age":"20",
	}

	fmt.Println(info) //map[age:20 name:username]

	//for range遍历map
	for k,v := range info{
		fmt.Println(k,v)
	}
    //判断键是否存在
	v, ok := info["name"]
	fmt.Println(v,ok)  //username true

	val, ok_ := info["xxx"]
	fmt.Println(val,ok_)  // 返回空和false

	//删除map对象的元素

	delete(info, "name")

	fmt.Println(info)   //map[age:20]

	//定义map类型的切片

	var infos = make([]map[string]string, 3, 3)
	fmt.Println(infos[0]) //map[]  不初始化默认值是nil

	if infos[0]==nil{
		infos[0] = map[string]string{
			"username":"name",
			"age":"age",
		}
	}

	fmt.Println(infos)   //[map[username:name age:age] map[] map[]]


	//map类型的值定义为切片

	var infoss = make(map[string][]string)

	infoss["hobby"] = []string{
		"python",
		"php",
	}
	fmt.Println(infoss)  //map[hobby:[python php]]

	for key, val := range infoss{
		fmt.Println(key, val)   //hobby [python php]
		for _, val_ := range val{
			fmt.Println(val_)    //python  php
		}
	}


}