读取外部JSON文件

Question

I am trying to read the following JSON file:

{
    "a":1,
    "b":2,
    "c":3
}

I have tried this but I found that I had to write each field of the JSON file into a struct but I really don't want to have all my JSON file in my Go code.

import (
    "fmt"
    "encoding/json"
    "io/ioutil"
)

type Data struct {
    A string `json:"a"`
    B string `json:"b"`
    C string `json:"c"`
}

func main() {
    file, _ := ioutil.ReadFile("/path/to/file.json")
    data := Data{}

    if err := json.Unmarshal(file ,&data); err != nil {
        panic(err)
    }
    for _, letter := range data.Letter {
        fmt.Println(letter)
    }
}

Is there a way to bypass this thing with something like json.load(file) in Python?

Answer 1

If you only want to support integer values, you could unmarshal your data into a map[string]int. Note that the order of a map is not defined, so the below program's output is non-deterministic for the input.

package main

import (
    "fmt"
    "encoding/json"
    "io/ioutil"
)

func main() {
    file, _ := ioutil.ReadFile("/path/to/file.json")
    var data map[string]int

    if err := json.Unmarshal(file ,&data); err != nil {
        panic(err)
    }
    for letter := range data {
        fmt.Println(letter)
    }
}