Why do these golang JSON Unmarshal examples behave differently?-CodePudding

I'm puzzled by the following behavior and I'm trying to figure out what to do about it. Can anyone please explain to me why these behave differently? Why isn't web_url read into Bar.Url?

package main

import (
    "encoding/json"
    "fmt"
    "testing"
)

type Foo struct {
    Web_url string
}

type Bar struct {
    Url string `json:'web_url'`
}

func TestJson(t *testing.T) {
    j := []byte(`{"web_url":"xyz"}`)

    f := &Foo{}
    err := json.Unmarshal(j, f)
    fmt.Printf("err: %v, f: % v\n", err, f)


    b := &Bar{}
    err = json.Unmarshal(j, b)
    fmt.Printf("err: %v, b: % v\n", err, b)
}

Results...

go test -v -run TestJson
=== RUN   TestJson
err: <nil>, f: &{Web_url:xyz}
err: <nil>, b: &{Url:}
--- PASS: TestJson (0.00s)
PASS
ok      gitlabsr.nuq.ion.nokia.net/sr/linux/gitlab-tools/internal/junk

CodePudding user response：

Using single quotes in struct tag definition caused this error.

package main

import (
    "encoding/json"
    "fmt"
    "testing"
)

type Foo struct {
    Web_url string
}

type Bar struct {
    Url string `json:"web_url"`
}

func TestJson(t *testing.T) {
    j := []byte(`{"web_url":"xyz"}`)

    f := &Foo{}
    err := json.Unmarshal(j, f)
    fmt.Printf("err: %v, f: % v\n", err, f)


    b := &Bar{}
    err = json.Unmarshal(j, b)
    fmt.Printf("err: %v, b: % v\n", err, b)
}