无法设置结构的属性 [英] Unable to set the property of a struct

问题描述

我正在尝试学习如何在 go 中使用结构体.

I'm trying to learn how to use structs in go.

我有以下包裹

// src/db/db.go
package db

type DB struct {
  pk string
}

func (db DB) SetPk(s string)  {
  db.pk = s
}
func (db DB) GetPk() string {
  return db.pk
}

这是我的 main.go

And this is my main.go

package main

import (
  "log"
  "db"
)

func main() {

  d := db.DB{}
  d.SetPk("Hello World")
  log.Println(d.GetPk())

}

当我运行命令 go run main.go 时，我的命令提示符中出现换行符.我验证了 SetPk 和 GetPk 都被触发，并且 SetPk 正在为 db.pk 分配一个值.但是在 GetPk 被触发的那一刻，db.pk 又是空的.

When I run the command go run main.go, I get a line break in my command prompt. I verified that both the SetPk and GetPk are being fired, and that the SetPk is assigning a value to db.pk. But the moment GetPk is fired, db.pk is empty again.

如何让db对象保留pk值并在GetPk中返回?

How do I get the db object to retain the pk value and return it in GetPk?

推荐答案

这是因为您需要使方法通过指向变量的指针而不是副本来工作.目前，每种方法仅使用原始副本(空白)来运行该方法.下面就可以了.

It's because you need to make the methods work off of a pointer to the variable and not a copy. Currently each method only uses a copy of the original (which is blank) to run the method. Below will work.

// src/db/db.go
package db

type DB struct {
  pk string
}
// Use the pointer back to the object
func (db *DB) SetPk(s string)  {
  db.pk = s
}
// Use the pointer back to the object
func (db *DB) GetPk() string {
  return db.pk
}

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