Go language serialization and deserialization and how to change the uppercase of the json key value to lowercase if the json after serialization is empty

go语言序列化

定义嵌套结构体

type Animal struct {
    
	Name string
}

type Person2 struct {
    
	Name string
	Age  int
	Animal Animal
}

Use serialized packages

func main() {
    
	p:= Person2{
    
		Name: "小花",
		Age: 121,
		Animal: Animal{
    
			Name: "旺财",
		},
	}

	json, err := json.Marshal(&p)
	if err !=nil{
    
		panic("error!!!")
	}
	fmt.Printf(string(json))

}

结果：
{“Name”:“小花”,“Age”:121,“Animal”:{“Name”:“旺财”}}

关于goafter serializationjsondata is empty andjson数据的keyIt's a matter of how to change uppercase to lowercase

Assume in the above struct,We start lowercase for all member variables,只有Animal是大写.Then the value after serialization is：
{“”,“Animal”:{}}.
在goVariables in the language that start with lowercase are private,Variables starting with a capital letter are shared.把personPass in the serialized package,Then it's not the same package,因此访问不到,Serialization is thatnull.
解决办法：
Change the variable name to uppercase.
优化：Because capitalization does not conform to the norm of writing.So we want to get the property name in lower casejson数据.So how to do it？

//Add it after the corresponding property name`json:"字段名"`.The field name here is after parsingjson的key值
type Person2 struct {
    
	Name string `json:"name"`
	Age  int `json:"age"`
	Animal Animal
}

运行结果：
{“name”:“小花”,“age”:121,“Animal”:{“Name”:“旺财”}}.
so 神奇！

goLanguage deserialization

调用Unmarshal包,Help me convert to the specified structure data

Let's make a small change to the structure first：

type Person2 struct {
    
	Name string `json:"name"`
	Age  int `json:"age"`
	Animal []Animal
}

Deserialize into the specified structure：

	str := `{"Name":"小花","Age":121,"Animal":[{"Name":"旺财"},{"Name":"旺财2"}]}`
	c1 := &Person2{
    }
	err := json.Unmarshal([]byte(str), c1)
	if err != nil {
    
		fmt.Println("json unmarshal failed!")
		return
	}
	fmt.Printf("%v",*c1)

打印的结果：
{小花 121 [{旺财} {旺财2}]}