如何将struct的切片作为函数的指针传递并对其进行修改？

I have a slice of struct []student, and I want to modify its content with function.

type student struct {
    name string
    age int
}

students := []student{
    {"Doraemon", 30},
    {"King Kong", 25},
}

Thus, I decided to pass it as a pointer. May I know how to pass the slice as a reference to a function?

func addAge (s *[]student) error { //this code has error
    //everyone add 2 years old
    for i, e := range *s {
        s[i].age = s[i].age + 2
    }
    //make the first student much older
    s[0].age = s[0].age + 5
    return nil
}

I keep playing with Go Playground, but it gives many complains, such as

cannot range over s (type *[]student)
invalid operation: s[i] (type *[]student does not support indexing)
invalid indirect of s
...

How to precisely pass the reference of a slice of struct to a function? How to range the slice of struct? And how to change the value of the struct (modify the same struct in THE slice)?

I keep getting error while playing with s *[]student, range *s, s []student, s *[]*student ... so hard to get it correct...

sorry for my NEWBIE question, still learning GO... trying hard

Slices are passed by reference, so as long as you are modifying the existing slice content you should not explicitly pass a pointer.

package main

import (
    "fmt"
)

type student struct {
    name string
    age int
}

func main() {
    students := []student{
        {"Doraemon", 30},
        {"King Kong", 25},
    }

    err := addAge (students)

    fmt.Println(students)
    if err != nil {
        fmt.Println("error")
    }
}

func addAge (s []student) error {
    for i, _ := range s {
        s[i].age = 3
    }
    return nil
}

Now, for your addAdditinalStudent function you should actually use the append function. Plus, have in mind

..., since the slice header is always updated by a call to append, you need to save the returned slice after the call. In fact, the compiler won't let you call append without saving the result. Slices#append

// add student
students = append(students, student{"Test", 33})

Go Playground

in Go you can pass items by value ([]student) or by reference ([]*student). When you want to operate on the values of a struct{} you should pass it to a function with its reference (the pointer).

So you can do something like this:

type student struct {
    name string
    age int
}

func addTwoYearsToAll(students []*student){
  for _, s := range students {
        s.age += 2
     }
}

This way you're working with the same exact items you build when appending to the slice. Playground example.

Also take a look at Are Golang function parameter passed as copy-on-write?