Golang : How to convert JSON string to map and slice
Couple of simple examples on how to convert JSON string to map and slice(array).
Simple and straightforward way of converting one line of JSON string.
package main
import (
"encoding/json"
"fmt"
)
func main() {
jsonStr := `{"Name":"Adam","Age":36,"Job":"CEO"}`
personMap := make(map[string]interface{})
err := json.Unmarshal([]byte(jsonStr), &personMap)
if err != nil {
panic(err)
}
for key, value := range personMap {
fmt.Println("index : ", key, " value : ", value)
}
}
Output:
index : Name value : Adam
index : Age value : 36
index : Job value : CEO
Convert multiple lines of JSON string to map and append each line into a slice(array).
package main
import (
"encoding/json"
"fmt"
"strconv"
)
func main() {
jsonStr := `[{
"Name": "Adam",
"Age": 36,
"Job": "CEO"
}, {
"Name": "Eve",
"Age": 34,
"Job": "CFO"
}, {
"Name": "Mike",
"Age": 38,
"Job": "COO"
}]`
type Person struct {
Name string
Age int
Job string
}
var people []Person
var personMap []map[string]interface{}
err := json.Unmarshal([]byte(jsonStr), &personMap)
if err != nil {
panic(err)
}
for _, personData := range personMap {
// convert map to array of Person struct
var p Person
p.Name = fmt.Sprintf("%s", personData["Name"])
p.Age, _ = strconv.Atoi(fmt.Sprintf("%v", personData["Age"]))
p.Job = fmt.Sprintf("%s", personData["Job"])
people = append(people, p)
}
fmt.Println(people)
}
Output:
[{Adam 36 CEO} {Eve 34 CFO} {Mike 38 COO}]
References:
https://www.socketloop.com/tutorials/golang-iterate-map
https://www.socketloop.com/references/golang-encoding-json-decoder-decode-function-example
https://www.socketloop.com/tutorials/golang-covert-map-slice-array-to-json-xml-format
See also : Golang : Covert map/slice/array to JSON or XML format
By Adam Ng
IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.
Advertisement
Tutorials
+7.3k Golang : Gorrila set route name and get the current route name
+12.9k Golang : How to get a user home directory path?
+5.5k Get website traffic ranking with Similar Web or Alexa
+22.9k Golang : Read a file into an array or slice example
+13.2k Golang : Read XML elements data with xml.CharData example
+6.9k Golang : Get environment variable
+7.3k Golang : Dealing with struct's private part
+10k Golang : cannot assign type int to value (type uint8) in range error
+8.1k Useful methods to access blocked websites
+26.8k Golang : Find files by name - cross platform example
+7.2k Golang : Word limiter example
+7.9k How to show different content from website server when AdBlock is detected?