转到更新切片迭代错误“不支持索引". [英] Go update slice iterating error "does not support indexing"

问题描述

我正在尝试遍历切片值并更新一个或多个值，通过索引访问它或遍历它们.那我有以下问题.

I'm trying to iterate through slice values and update one or more values, accessing it by index or iterating through them. Then I have the following problem.

package main

import "fmt"

type Member struct {
    Name, Surname string
    Age           int
}
type Members []Member

func main() {
    members1 := Members{
        {"Bob", "Doe", 30},
        {"Jack", "Doe", 30},
        {"John", "Doe", 30},
    }
    members1.ModifyName()
    members1.ModifyAllNames1()
    members1.ModifyAllNames2()
    fmt.Println(members1)
}

func (members *Members) ModifyName() {

    *members[0].Name = "-"
}

func (members *Members) ModifyAllNames1() {

    for i := 0; i < len(*members); i++ {
        *members[i].Name = "-"
    }
}

func (members *Members) ModifyAllNames2() {

    for _, m := range *members {
        m.Name = "-"
    }
}   

然后我得到以下错误:

invalid operation: members[0] (type *Members does not support indexing)
invalid operation: members[i] (type *Members does not support indexing)

推荐答案

类型 *成员不支持索引，类型成员可以.

Type *Members does not support indexing, type Members does.

m := make([]Members, 5)
pm := &m

m[:2]     // good
pm[:2]    // bad
(*pm)[:2] // good

---

http://play.golang.org/p/_26TUBHdDm

package main

import "fmt"

type Member struct {
    Name, Surname string
    Age           int
}
type Members []Member

func main() {
    members1 := Members{
        {"Bob", "Doe", 30},
        {"Jack", "Doe", 30},
        {"John", "Doe", 30},
    }
    members1.ModifyName()
    members1.ModifyAllNames1()
    members1.ModifyAllNames2()
    fmt.Println(members1)
}

func (members *Members) ModifyName() {
    (*members)[0].Name = "-"
}

func (members *Members) ModifyAllNames1() {
    for i := 0; i < len(*members); i++ {
        (*members)[i].Name = "-"
    }
}

func (members *Members) ModifyAllNames2() {
    for _, m := range *members {
        m.Name = "-"
    }
}

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