Decode JSON into Objects in Golang

Suppose we have a JSON that looks like this.

{
   "name":"Mukul Latiyan",
   "age":10,
   "sports":[
      "football",
      "tennis",
      "cricket"
   ]
}

Now, we want to convert this JSON into struct fields which we can access later and maybe iterate over too.

In order to do that, we need to first make a struct that will satisfy the fields of the above JSON.

The struct shown below will work just fine for the above JSON.

type Person struct {
   Name string `json:"name"`
   Age int `json:"age"`
   Sports []string `json:"sports"`
}

Now, the next step is to convert the above JSON object into a slice of bytes in Go, with the help of type conversion, and then, we will pass that slice of bytes to the Unmarshal() function along with the Person object as the second argument.

Example

Consider the code shown below.

package main

import (
   "encoding/json"
   "fmt"
)

type Person struct {
   Name string `json:"name"`
   Age int `json:"age"`
   Sports []string `json:"sports"`
}

func main() {
   text := []byte(
      `{
         "name":"Mukul Latiyan",
         "age":10,
         "sports":["football","tennis","cricket"]

      }`)
   var p Person
   err := json.Unmarshal(text, &p)
   if err != nil {
      panic(err)
   }
   fmt.Println(p.Name)
   fmt.Println(p.Age)
   for _, value := range p.Sports {
      fmt.Println(value)
   }
}

In the above code, after calling the Unmarshal function, we are simply printing the values of different fields of the struct.

If we run the command go run main.go on the above code, then we will get the following output in the terminal.

Output

Mukul Latiyan
10
football
tennis
cricket