Golang中结构体字段未定义错误怎么修复

package main

import "fmt"

type Person struct {
    Name string
    Age  int
}

func main() {
    p := Person{Name: "Alice", Age: 30}
    // 错误示例：访问不存在的字段
    // fmt.Println(p.Addres) // 编译错误：p.Addres undefined (type Person has no field or method Addres)

    // 正确示例：访问存在的字段
    fmt.Println(p.Name)
    fmt.Println(p.Age)
}

package mypackage

type MyStruct struct {
    PublicField  string // 公开字段
    privateField int    // 私有字段
}

func (m *MyStruct) GetPrivateField() int {
    return m.privateField
}

func (m *MyStruct) SetPrivateField(value int) {
    m.privateField = value
}

package main

import (
    "fmt"
    "your_module_name/mypackage" // 替换为你的模块名
)

func main() {
    s := mypackage.MyStruct{PublicField: "Hello"}
    fmt.Println(s.PublicField) // 可以访问公开字段

    // 错误示例：无法直接访问私有字段
    // fmt.Println(s.privateField) // 编译错误：s.privateField undefined (cannot refer to unexported field or method mypackage.MyStruct.privateField)

    // 正确示例：通过公开方法访问私有字段
    fmt.Println(s.GetPrivateField()) // 0 (默认值)
    s.SetPrivateField(10)
    fmt.Println(s.GetPrivateField()) // 10
}

package main

import "fmt"

type Address struct {
    City    string
    ZipCode string
}

type Employee struct {
    Name    string
    Address Address
}

func main() {
    e := Employee{
        Name: "Bob",
        Address: Address{
            City:    "New York",
            ZipCode: "10001",
        },
    }

    // 正确示例：访问嵌套结构体的字段
    fmt.Println(e.Address.City)
    fmt.Println(e.Address.ZipCode)

    // 错误示例：直接访问不存在的字段
    // fmt.Println(e.City) // 编译错误：e.City undefined (type Employee has no field or method City)
}

package main

import "fmt"

type Data struct {
    Value int
}

func main() {
    d := &Data{Value: 42}

    // 正确示例：通过指针访问结构体字段
    fmt.Println(d.Value) // Golang会自动解引用，等价于 (*d).Value

    // 错误示例：如果d不是指针，则不能使用 -> 操作符
    // fmt.Println(d->Value) // 编译错误：invalid indirect of d (type Data has no field or method Value)
}

package main

import (
    "fmt"
    "reflect"
)

type Config struct {
    Host string `json:"host"`
    Port int    `json:"port"`
}

func main() {
    cfg := Config{Host: "localhost", Port: 8080}

    // 使用反射获取结构体类型
    t := reflect.TypeOf(cfg)

    // 检查是否存在某个字段
    field, ok := t.FieldByName("Host")
    if ok {
        fmt.Println("Field Name:", field.Name)
        fmt.Println("Field Type:", field.Type)
        fmt.Println("Field Tag:", field.Tag.Get("json"))
    } else {
        fmt.Println("Field not found")
    }

    // 检查是否存在不存在的字段
    _, ok = t.FieldByName("Address")
    if !ok {
        fmt.Println("Field 'Address' not found")
    }
}