Golang Parse JSON

Go provides the encoding/json package that allows you to work with JSON data. JSON is a powerful and incredible data exchange format.

In this article, we will learn how you can parse JSON data using the encoding/json package.

Golang Unmarshal

Unmarshal is the contrary of marshal. It allows you to convert byte data into the original data structure.

In Go, the json.Unmarshal() method handles unmarshaling.

Consider an example JSON string as:

{"Full_Name":"John Doe","Age":32,"Retired":false,"Salary":140000}

Let us start by creating a struct to match the byte code after we perform the Unmarshal.

type User struct {
Full_Name string `json:"Full_Name"`
Age string `json:"Age"`
Retired bool `json:"Retired"`
Salary int `json:"Salary"`
}

The next step is to create the JSON string into byte code. Once we have the byte code, we can Unmarshal it into a struct.

user_info_bytes := []byte(user_info)

Once we have the byte code, we can unmarshall it into struct.

var employee User
json.Unmarshal(user_info_bytes, &employee)

Once we have the struct, we can access the values as:

fmt.Println(employee.Full_Name)
fmt.Println(employee.Age)
fmt.Println(employee.Retired)
fmt.Println(employee.Salary)

The above code should return:

John Doe
32
false
140000

The full source code is as shown below:

func unmarshal_struct() {
user_info := `{"Full_Name":"John Doe","Age":32,"Retired":false,"Salary":140000}`

type User struct {
Full_Name string `json:"Full_Name"`
Age string `json:"Age"`
Retired bool `json:"Retired"`
Salary int `json:"Salary"`
}
user_info_bytes := []byte(user_info)
var employee User
json.Unmarshal(user_info_bytes, &employee)
fmt.Println(employee.Full_Name)
fmt.Println(employee.Age)
fmt.Println(employee.Retired)
fmt.Println(employee.Salary)
}

Conclusion

This was a short guide that illustrates how to convert JSON data into a structure. To learn more, check our tutorial on Golang Marshal and Unmarshal.

Thanks for reading & Happy Coding!

Golang Parse JSON

Golang Unmarshal

Conclusion

About the author

John Otieno