json.Unmarshal 忽略 json 字符串中的 json 字符串值，不要尝试解析它

Question

I need to unmarshal a json string, but treat the 'SomeString' value as a string and not json. The unmarshaler errors when attempting this Not sure if this is possible. Thanks.

type Test struct{
    Name        string `json:"Name"`
    Description string `json:"Description"`
    SomeString  string `json:"SomeString"`
}

func main() {
    a := "{\"Name\":\"Jim\", \"Description\":\"This is a test\", \"SomeString\":\"{\"test\":{\"test\":\"i am a test\"}}\" }"

    var test Test

    err := json.Unmarshal([]byte(a), &test)
    if err !=nil{
        fmt.Println(err)
    }

    fmt.Println(a)

    fmt.Printf("%+v\n", test)
}

Answer 1

Your input is not a valid JSON. See this part:

\"SomeString\":\"{\"test

There's a key SomeString and it has a value: {\ . The 2nd quote inside its supposed value closes it. The subsequent characters test are not part of SomeString 's value, they appear "alone", but if they would be the name of the next property, it would have to be quoted. So you get the error invalid character 't' after object key:value pair .

It's possible of course to have a JSON string as the value and it's not parsed, but the input must be valid JSON.

For example, using a raw string literal:

a := `{"Name":"Jim", "Description":"This is a test", "SomeString":"{\"test\":{\"test\":\"i am a test\"}}" }`

Using this input, the output will be (try it on the Go Playground ):

{"Name":"Jim", "Description":"This is a test", "SomeString":"{\"test\":{\"test\":\"i am a test\"}}" }
{Name:Jim Description:This is a test SomeString:{"test":{"test":"i am a test"}}}

This works as intended, your problem is how you specify your input. "" is already an interpreted (Go) literal, and you want another, JSON escaped string inside it. In that case you'd have to escape twice!

Like this:

a := "{\"Name\":\"Jim\", \"Description\":\"This is a test\", \"SomeString\":\"{\\\"test\\\":{\\\"test\\\":\\\"i am a test\\\"}}\" }"

This will output the same, try it on the Go Playground .