package main

import (
    "encoding/json"
    "fmt"
)

func main() {
    // jsonDeal([]byte(`{"name":"xiaoming","course":["1111","2222"]}`))
    // jsonDeal([]byte(`{"name":"xiaoming","course":["1111"]}`))
    jsonDeal([]byte(`{"name":"xiaoming","course":[null]}`))
    // jsonDeal([]byte(`{"name":"xiaoming","course":[]}`))
    // jsonDeal([]byte(`{"name":"xiaoming","course":null}`))
}

type User struct {
    Name   string   `json:"name"`
    Course []string `json:"course"`
}

func jsonDeal(data []byte) {
    var oneUser User
    if err := json.Unmarshal(data, &oneUser); err != nil {
        panic(err)
        return
    }
    fmt.Println("==============")
    fmt.Println("oridata:", string(data))
    fmt.Println("json result:", oneUser)
    fmt.Println("course num:", len(oneUser.Course))
    return
}