基础语法-map使用（8）

总体

代码

//demo_14.go
package main

import (
	"fmt"
)

func main() {
	var p1 map[int]string
	p1 = make(map[int]string)
	p1[1] = "Tom"
	fmt.Println("p1 :", p1)

	var p2 map[int]string = map[int]string{}
	p2[1] = "Tom"
	fmt.Println("p2 :", p2)

	var p3 map[int]string = make(map[int]string)
	p3[1] = "Tom"
	fmt.Println("p3 :", p3)

	p4 := map[int]string{}
	p4[1] = "Tom"
	fmt.Println("p4 :", p4)

	p5 := make(map[int]string)
	p5[1] = "Tom"
	fmt.Println("p5 :", p5)

	p6 := map[int]string{
		1 : "Tom",
		2 : "aaa",
	}
	fmt.Println("p6 :", p6)
	p7 :=map[string]string{
		"a":"aaa",
	}
	fmt.Println("p7 :", p7)
}

输出

p1 : map[1:Tom]
p2 : map[1:Tom]
p3 : map[1:Tom]
p4 : map[1:Tom]
p5 : map[1:Tom]
p6 : map[1:Tom 2:aaa]
p7 : map[a:aaa]

高级使用

//demo_15.go
package main

import (
	"encoding/json"
	"fmt"
)

func main() {
	res := make(map[string]interface{})
	res["code"] = 200
	res["msg"]  = "success"
	res["data"] = map[string]interface{}{
		"username" : "Tom",
		"age"      : "30",
		"hobby"    : []string{"读书","爬山"},
	}
	fmt.Println("map data :", res)

	//序列化
	jsons, errs := json.Marshal(res)
	if errs != nil {
		fmt.Println("json marshal error:", errs)
	}
	fmt.Println("")
	fmt.Println("--- map to json ---")
	fmt.Println("json data :", string(jsons))

	//反序列化
	res2 := make(map[string]interface{})
	errs = json.Unmarshal([]byte(jsons), &res2)
	if errs != nil {
		fmt.Println("json marshal error:", errs)
	}
	fmt.Println("")
	fmt.Println("--- json to map ---")
	fmt.Println("map data :", res2)
}

基础用法

//删除
        person := map[int]string{
		1 : "Tom",
		2 : "Aaron",
		3 : "John",
	}
	fmt.Println("data :",person)

	delete(person, 2)
	fmt.Println("data :",person)

	person[2] = "Jack"
	person[3] = "Kevin"
	fmt.Println("data :",person)