JSON

Working with JSON in Go is straightforward and can be achieved using the encoding/json package, which provides functionalities to encode Go data structures into JSON and decode JSON into Go data structures.

Nice to know Struts Tags

Struct to JSON

Using json.Marshal is the simple way. The json.NewEncoder is used to create a new JSON encoder that writes to an io.Writer interface, such as a file or network connection. This allows you to easily encode Go data structures to JSON and write them to an external destination.

Example

run command

go run src/http/struct_to_json.go

package main

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

type Person struct {
    Name string `json:"name"`
    Age  int    `json:"age"`
}

func main() {
    person := Person{Name: "Gabriel", Age: 25}
    jsonData, err := json.Marshal(person)
    fmt.Println("Using Marshal")
    if err != nil {
        fmt.Println("Error:", err)
        return
    }
    fmt.Println("JSON Data:", string(jsonData))
    fmt.Println("***")
    fmt.Println("Using NewEncoder")
    file, _ := os.Create("src/http/person.json")
    defer file.Close()
    err = json.NewEncoder(file).Encode(person)
}

output

Using Marshal
JSON Data: {"name":"Gabriel","age":25}
***
Using NewEncoder

JSON to Struct

Using json.Unmarshal is the simple way. The json.NewDecoder is used to create a new JSON decoder that reads from an io.Reader interface, such as a file or network connection. This enables you to easily decode JSON data from an external source into Go data structures.

Example

run command

go run src/http/json_to_struct.go

package main

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

type Person struct {
    Name string `json:"name"`
    Age  int    `json:"age"`
}

func main() {
    person := Person{Name: "Gabriel", Age: 25}
    jsonData, err := json.Marshal(person)
    fmt.Println("Using Marshal")
    if err != nil {
        fmt.Println("Error:", err)
        return
    }
    fmt.Println("JSON Data:", string(jsonData))
    fmt.Println("***")
    fmt.Println("Using NewEncoder")
    file, _ := os.Create("src/http/person.json")
    defer file.Close()
    err = json.NewEncoder(file).Encode(person)
}

output

Using Unmarshal
Person: {Gabriel 25}
***
Using NewDecoder
Person2: {Gabriel 25}