七爪源码：在 Golang 中使用 JSON

Golang 提供了多个 API 来处理 JSON，包括使用 encoding/json 包来往来于内置和自定义数据类型。

Golang 使用 Marshal() 和 Unmarshal() 方法将对象转换为 JSON 和 JSON 数据为字符串。 这些方法以字节格式返回数据，我们需要将返回的数据更改为 JSON 或 String。

在本文中，我们将了解 Golang 中的数据编组和解组。

Golang 中的元帅

将 Go 对象转换为 JSON 在 Golang 中称为编组，使用内置的 encoding/json 包来执行 JSON 相关的操作。

json.Marshal(v any) ([]byte, error)

借助上述函数，Marshal 返回 v 的 JSON 编码，进一步，我们可以将字节数据转换为字符串并返回。

package main

import (
	"encoding/json"
	"fmt"
)

type Books struct {
	Name   string
	Author string
	Rating float64
}

func main() {
	book := Books{Name: "Rich Dad Poor Dad", Author: "Robert Kiyosaki and Sharon Lechter", Rating: 4.7}
	bookData, err := json.Marshal(book)
	if err != nil {
		fmt.Println(err)
	}
	fmt.Println(string(bookData))
	// Output: {"Name":"Rich Dad Poor Dad","Author":"Robert Kiyosaki and Sharon Lechter","Rating":4.7}
}

在 Golang 中解组

这与元帅正好相反。 将 JSON(Byte data) 转换为 Struct 并将结果存储在变量指向的值中。

json.Unmarshal(data []byte, v any)

借助上述函数，Unmarshal 返回 JSON 数据的实际值。

package main

import (
	"encoding/json"
	"fmt"
)

type Book struct {
    Name string `json:"name"`
    Author string `json:"author"`
    Rating float64 `json:"rating"`
}

func main() {		
	bookJsonData := `{"Name":"Hamlet", "Author":"William Shakespeare", "Rating":4.3}`	
	bookBytes := []byte(bookJsonData)
	var book Book
	json.Unmarshal(bookBytes, &book)
	fmt.Println(book.Name, "," , book.Author, "," ,book.Rating)
  //Output: Hamlet , William Shakespeare , 4.3
}

目前让我们看看使用上述函数编写一些代码并对 JSON 数据集进行一些修改。

让我们思考给定的数据集：

{
  "_id": "62b435e407bc586da8d297cb",
  "index": 4,
  "guid": "57a22da3-d791-4420-9245-465a34730537",
  "gender": "male",
  "company": "EZENT",
  "email": "barrerajarvis@ezent.com",
  "phone": "+1 (801) 499-2594",
  "friends": [
    {
      "id": 0,
      "name": "Dale Sexton",
      "email": "Dale.sexton@example.com"
    },
    {
      "id": 1,
      "name": "Watkins Puckett",
      "email": "Watkins.puckett@example.com"
    },
    {
      "id": 2,
      "name": "Luann Bond",
      "email": "Luann.bond@example.com"
    }
  ],
  "greeting": "Hello, Barrera Jarvis! You have 8 unread messages.",
  "favoriteFruit": "banana"
}

并且，问题陈述是写下从朋友数组中删除电子邮件字段的代码。

目前，让我们写下修改 JSON 数据的代码：

package main

import (
	"encoding/json"
	"log"
	"os"
)

func main() {
	inputs := `{
		"_id": "62b435e407bc586da8d297cb",
		"index": 4,
		"guid": "57a22da3-d791-4420-9245-465a34730537",
		"gender": "male",
		"company": "EZENT",
		"email": "barrerajarvis@ezent.com",
		"phone": "+1 (801) 499-2594",
		"friends": [
		  {
			"id": 0,
			"name": "Dale Sexton",
			"email": "Dale.sexton@example.com"
		  },
		  {
			"id": 1,
			"name": "Watkins Puckett",
			"email": "Watkins.puckett@example.com"
		  },
		  {
			"id": 2,
			"name": "Luann Bond",
			"email": "Luann.bond@example.com"
		  }
		],
		"greeting": "Hello, Barrera Jarvis! You have 8 unread messages.",
		"favoriteFruit": "banana"
	  }`
	var v any
	if err := json.Unmarshal([]byte(inputs), &v); err != nil {
		log.Fatal(err)
	}

	if v, ok := v.(map[string]any); ok {
		// if the "inputs" field is a JSON array ...
		if v, ok := v["friends"].([]any); ok {
			// for each element in the JSON array ...
			for _, v := range v {
				// if the element is a JSON object ...
				if v, ok := v.(map[string]any); ok {
					// remove key boo
					delete(v, "email")
				}
			}
		}
	}

	p, _ := json.Marshal(v)
	os.Stdout.Write(p)
	//Output : {"_id":"62b435e407bc586da8d297cb","company":"EZENT","email":"barrerajarvis@ezent.com","favoriteFruit":"banana","friends":[{"id":0,"name":"Dale Sexton"},
			// {"id":1,"name":"Watkins Puckett"},{"id":2,"name":"Luann Bond"}], "gender":"male","greeting":"Hello, Barrera Jarvis! You have 8 unread messages.",
				// "guid":"57a22da3-d791-4420-9245-465a34730537","index":4,"phone":"+1 (801) 499-2594"}

}

我希望你喜爱这篇文章。

谢谢阅读

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