由于编码，解组返回空白对象

Question

I'm attempting to unmarshal a raw json string. There seems to be an error with encoding but I can't quite figure it out.

package main

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

type Foo struct {
    Transmission string `json:"transmission"`
    Trim         string `json:"trim"`
    Uuid         string `json:"uuid"`
    Vin          string `json:"vin"`
}

func main() {

    var foo Foo

    sample := `{
        "transmission": "continuously\x20variable\x20automatic",
        "trim": "SL",
        "uuid" : "6993e4090a0e0ae80c59a76326e360a1",
        "vin": "5N1AZ2MH6JN192059"
    }`

    err := json.Unmarshal([]byte(sample), &foo)
    if err != nil {
        log.Fatal(err)
    }
    fmt.Println(foo)

}

2009/11/10 23:00:00 invalid character 'x' in string escape code

It works if transmission entry is removed.

Here is a working playground.

Answer 1

Your input is not valid JSON. The JSON spec states that

All code points may be placed within the quotation marks except for the code points that must be escaped: quotation mark (U+0022), reverse solidus (U+005C), and the control characters U+0000 to U+001F.

Additionally, although there are two-character escape sequences, \x is not one of them, and thus it is being correctly interpreted as an invalid escape sequence by the Go parser. If you want to have a backslash literal in your JSON, it needs to be represented by \\ in the JSON input itself. See a modified version of your example: https://play.golang.org/p/JZdPJGpPR5q

(note that this is not an issue with your Go string literal since you're already using a raw (``) string literal—the JSON itself needs to have two backslashes.)