golang for循环时修改自身的值

一、尝试 v.Name 直接修改

1、代码

package main

import "fmt"

type User struct {
    
    
	Name string
}

func main() {
    
    
	users := []User{
    
    {
    
    Name: "姓名1"}, {
    
    Name: "姓名2"}, {
    
    Name: "姓名3"}}
	for _, v := range users {
    
    
		v.Name = "暂无"
	}
	fmt.Println(users)
}

2、打印

[{
    
    姓名1} {
    
    姓名2} {
    
    姓名3}]

Process finished with exit code 0

3、结论

• 修改失败

二、println() 函数查看内存地址是否一致

1、代码

package main

type User struct {
    
    
	Name string
}

func main() {
    
    
	users := []User{
    
    {
    
    Name: "姓名1"}, {
    
    Name: "姓名2"}, {
    
    Name: "姓名3"}}
	for k, v := range users {
    
    
		println(&users[k], " VS ", &v)
	}
}

2、打印

0xc00003bf48  VS  0xc00003bf38
0xc00003bf58  VS  0xc00003bf38
0xc00003bf68  VS  0xc00003bf38

Process finished with exit code 0

3、结论

• 内存地址不一样，修改无效

三、users[k].Name 修改

1、代码

package main

import "fmt"

type User struct {
    
    
	Name string
}

func main() {
    
    
	users := []User{
    
    {
    
    Name: "姓名1"}, {
    
    Name: "姓名2"}, {
    
    Name: "姓名3"}}
	for k := range users {
    
    
		users[k].Name = "暂无"
	}
	fmt.Println(users)
}

2、打印

[{
    
    暂无} {
    
    暂无} {
    
    暂无}]

Process finished with exit code 0

3、结论

• 修改成功