Golang JSON取消编组到字段，但不编组到JSON响应

Question

I want to be able to access a struct field that's resulted from a JSON unmarshal, BUT I want to use that same struct to hide the field when it is marshaled.

Example:

type MyStruct struct {
    GoodField string `json:"goodField"`
    SecretField string `json:"secret"`
}

Incoming JSON gets unmarshaled and the secret field is accessible Use the same MyStruct in the server response but hide the secret field.

I've looked at using omitempty and - tags, not working.

Answer 1

you were on the right track with omitempty you just have to set SecretField to "" for it to take effect

package main

import (
    "fmt"
    "encoding/json"
)

type MyStruct struct {
    GoodField string `json:"goodField"`
    SecretField string `json:"secret,omitempty"`
}

func main() {

    data := MyStruct{}

    s := `{"goodField": "xxx", "secret": "yyy"}`

    json.Unmarshal([]byte(s), &data);

    fmt.Println(data.GoodField, data.SecretField);

    data.SecretField = ""

    response, _ := json.Marshal(data)

    fmt.Println(string(response))

}