A code instance that USES omitempty in go

Use of omitempty in go

Direct code:

package main
import (
  "encoding/json"
  "fmt"
)
type Person struct {
  Name string `json:"name"`
  Age int  `json:"age"`
  Addr string `json:"addr,omitempty"`
}
func main() {
  p1 := Person{
    Name: "taoge",
    Age: 30,
  }
  data, err := json.Marshal(p1)
  if err != nil {
    panic(err)
  }
  fmt.Printf("%s\n", data)
  fmt.Println(p1.Name, p1.Age, p1.Addr)
  p2 := Person{
    Name: "Cang Laoshi",
    Age: 18,
    Addr: "Japan",
  }
  data2, err := json.Marshal(p2)
  if err != nil {
    panic(err)
  }
  fmt.Printf("%s\n", data2)
  fmt.Println(p2.Name, p2.Age, p2.Addr)
}

Results:

{"name":"taoge","age":30}
taoge 30
{"name":"Cang Laoshi","age":18,"addr":"Japan"}
Cang Laoshi 18 Japan

As you can see, with omitempty, if addr is empty, there is no addr field in the generated json.

You can get rid of omitempty and try again.

Not much said.

conclusion