Golang React JS Technology Blog

Golang writing struct to JSON file

The json package has a MarshalIndent() function which is used to serialized values from a struct and write them to a file in JSON format.

Example

package main
 
import (
	"encoding/json"
	"io/ioutil"
)
 
type Salary struct {
        Basic, HRA, TA float64
    }
 
type Employee struct {
	FirstName, LastName, Email string
	Age                        int
	MonthlySalary              []Salary
}
 
func main() {
	data := Employee{
        FirstName: "Mark",
        LastName:  "Jones",
        Email:     "mark@gmail.com",
        Age:       25,
        MonthlySalary: []Salary{
            Salary{
                Basic: 15000.00,
                HRA:   5000.00,
                TA:    2000.00,
            },
            Salary{
                Basic: 16000.00,
                HRA:   5000.00,
                TA:    2100.00,
            },
            Salary{
                Basic: 17000.00,
                HRA:   5000.00,
                TA:    2200.00,
            },
        },
    }
 
	file, _ := json.MarshalIndent(data, "", " ")
 
	_ = ioutil.WriteFile("test.json", file, 0644)
}

Output

{
 "FirstName": "Mark",
 "LastName": "Jones",
 "Email": "mark@gmail.com",
 "Age": 25,
 "MonthlySalary": [
  {
   "Basic": 15000,
   "HRA": 5000,
   "TA": 2000
  },
  {
   "Basic": 16000,
   "HRA": 5000,
   "TA": 2100
  },
  {
   "Basic": 17000,
   "HRA": 5000,
   "TA": 2200
  }
 ]
}
The Salary struct is defined with json fields. The struct values are initialized and then serialize with the json.MarshalIndent() function. The serialized JSON formatted byte slice is received which then written to a file using the ioutil.WriteFile() function.
Most Helpful This Week
How to use WaitGroup to delay execution of the main function until after all goroutines are complete. Golang Concurrency Best Practices Golang write struct to XML file Pascal triangle in Go Programming Language How do you create an HTTP client in Go? How to remove all line breaks from a string in Golang?