dpnof28482 2013-08-08 07:05
浏览 33
已采纳

我可以在golang中获取指向地图值的指针吗?

I'm trying to use Go's flag package to dynamically generate FlagSets and collect the results in a map from flagname -> flag value.

My code looks like this:

import "flag"

fs := flag.NewFlagSet(strings.Join(commands, " "), flag.ExitOnError)
requiredFlags := []string{"flagA", "flagB"}
flags := make(map[string]string)

for _, f := range requiredFlags { 
    flags[f] = *fs.String(f, "", "") 
}  

This code compiles, but the map never gets updated after the FlagSet fs is parsed, so the values of "flagA" and "flagB" are both "". So this makes sense to me; flags is of type map[string]string after all, not map[string]*string. Unfortunately, I can't seem to fix this problem using pointers. I've tried every combination of referencing and dereferencing I can think of and I either end up with a nil pointer dereference (runtime error) or invalid indirect (compile time error).

How can I set up the map and FlagSet such that the map values are populated after the FlagSet is parsed?

  • 写回答

1条回答 默认 最新

  • dqz30992 2013-08-08 07:09
    关注

    What is wrong with

    flags := make(map[string]*string)
    for _, f := range requiredFlags { 
        flags[f] = fs.String(f, "", "") 
    }
    ...
    println(*(flags["flagA"]))
    

    ?

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论

报告相同问题?

悬赏问题

  • ¥30 关于用python写支付宝扫码付异步通知收不到的问题
  • ¥50 vue组件中无法正确接收并处理axios请求
  • ¥15 隐藏系统界面pdf的打印、下载按钮
  • ¥15 MATLAB联合adams仿真卡死如何解决(代码模型无问题)
  • ¥15 基于pso参数优化的LightGBM分类模型
  • ¥15 安装Paddleocr时报错无法解决
  • ¥15 python中transformers可以正常下载,但是没有办法使用pipeline
  • ¥50 分布式追踪trace异常问题
  • ¥15 人在外地出差,速帮一点点
  • ¥15 如何使用canvas在图片上进行如下的标注,以下代码不起作用,如何修改