英文:
Detect if JSON file has field
问题
我的应用程序从配置文件中读取设置：
file, _ := os.Open("config.json")config := config.Config{}err := json.NewDecoder(file).Decode(&config)if err != nil {//处理错误}
我的JSON配置文件大致如下：
{"site" : {"url" : "https://example.com"},"email" : {"key" : "abcde"}}
我的结构体如下：
type Site struct {Url string}type Email struct {Key string}type Config struct {Site SiteEmail Email}
我想要有一个选项，可以从JSON文件中删除email字段，以表示不使用电子邮件帐户，所以：
{"site" : {"url" : "https://example.com"}}
在Go中，如何检测JSON文件中是否存在特定字段，类似于以下代码：
if (在JSON文件中找到Email字段) {输出 "您想要接收电子邮件"} else {输出 "您不会收到电子邮件"}
英文:
My app reads settings from a config file:
file, _ := os.Open("config.json")config := config.Config{}err := json.NewDecoder(file).Decode(&config)if err != nil {//handle err}
My JSON config file looks something like this:
{"site" : {"url" : "https://example.com"},"email" : {"key" : "abcde"}}
My structs are:
type Site struct {Url string}type Email struct {Key string}type Config struct {Site SiteEmail Email}
I would like the option of removing the email field from the JSON file to indicate that no email account will be used so:
{"site" : {"url" : "https://example.com"}}
How do I detect if a specific field exists in the JSON file in Go so something on the lines of:
if (Email field found in JSON file) {output "You want to receive emails"} else {output "No emails for you!"}
答案1
得分: 24
将Config更改为
type Config struct {Site SiteEmail *Email}
使用c.Email != nil来测试JSON文件中是否将电子邮件指定为字符串值。如果c.Email == nil，则表示未指定电子邮件或为null。
英文:
Change Config to
type Config struct {Site SiteEmail *Email}
Use c.Email != nil to test if email is specified as a string value in the JSON file. If c.Email == nil, then email is not specified or null.
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