[ 常見問題 ] Converting Go struct to JSON

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Question
I am trying to convert a Go struct to JSON using the json package but all I get is {}. I am certain it is something totally obvious but I don't see it.

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1. package main  
2.   
3. import (  
4.     "fmt"  
5.     "encoding/json"  
6. )  
7.   
8. type User struct {  
9.     name string  
10. }  
11.   
12. func main() {  
13.     user := &User{name:"Frank"}  
14.     b, err := json.Marshal(user)  
15.     if err != nil {  
16.         fmt.Printf("Error: %s", err)  
17.         return;  
18.     }  
19.     fmt.Println(string(b))  
20. }  

HowTo
You need to export the User.name field so that the json package can see it. Rename the name field to Name:

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1. package main  
2.   
3. import (  
4.     "fmt"  
5.     "encoding/json"  
6. )  
7.   
8. type User struct {  
9.     Name string  
10. }  
11.   
12. func main() {  
13.     user := &User{Name: "Frank"}  
14.     b, err := json.Marshal(user)  
15.     if err != nil {  
16.         fmt.Println(err)  
17.         return  
18.     }  
19.     fmt.Println(string(b))  
20. }  

Output:

{"Name":"Frank"}