Go语言切片迭代：深入理解元素引用与高效修改策略

package main

import "fmt"

type Account struct {
    balance int
}

type AccountList []Account

func main() {
    accounts := AccountList{
        {balance: 10},
        {balance: 20},
        {balance: 30},
    }

    fmt.Println("初始状态:", accounts)

    // 尝试通过值副本修改（错误方式）
    for _, a := range accounts {
        a.balance = 100 // 这里修改的是 'a' 的副本
    }
    fmt.Println("通过副本修改后:", accounts) // 结果：切片元素未改变
}

package main

import "fmt"

type Account struct {
    balance int
}

type AccountList []Account

func main() {
    accounts := AccountList{
        {balance: 10},
        {balance: 20},
        {balance: 30},
    }

    fmt.Println("初始状态:", accounts)

    // 正确的修改方式：通过索引访问
    for i := range accounts {
        accounts[i].balance = 100 // 直接修改切片中索引 'i' 处的元素
    }
    fmt.Println("通过索引修改后:", accounts) // 结果：切片元素已改变
}

package main

import "fmt"

type Account struct {
    balance int
}

type AccountList []Account

func main() {
    accounts := AccountList{
        {balance: 10},
        {balance: 20},
        {balance: 30},
    }

    fmt.Println("初始状态:", accounts)

    // 优化多重修改：获取元素指针
    for i := range accounts {
        a := &accounts[i] // 获取切片中元素的指针
        a.balance = 100
        // 进一步操作 'a'，例如：
        // a.someOtherField = "new value"
        // a.status = "active"
    }
    fmt.Println("通过指针修改后:", accounts) // 结果：切片元素已改变
}

package main

import "fmt"

type Account struct {
    balance int
}

// AccountPtrList 存储 Account 结构体的指针
type AccountPtrList []*Account

func main() {
    // 初始化 Account 实例
    acc1 := &Account{balance: 10}
    acc2 := &Account{balance: 20}
    acc3 := &Account{balance: 30}

    accountsPtr := AccountPtrList{acc1, acc2, acc3}

    fmt.Println("初始状态 (通过指针列表):")
    for _, acc := range accountsPtr {
        fmt.Printf("{balance: %d} ", acc.balance)
    }
    fmt.Println()

    // 通过指针副本修改（直接修改原始数据）
    for _, a := range accountsPtr {
        a.balance = 100 // 这里修改的是指针指向的原始 Account 结构体
    }

    fmt.Println("通过指针副本修改后 (通过指针列表):")
    for _, acc := range accountsPtr {
        fmt.Printf("{balance: %d} ", acc.balance)
    }
    fmt.Println()

    // 验证原始 Account 实例是否也已改变
    fmt.Println("原始acc1的balance:", acc1.balance)
    fmt.Println("原始acc2的balance:", acc2.balance)
}