如何将字符串作为参数传递给Golang指针接收函数?[复制]

我正在尝试一个简单的Go结构与值和指针接收器函数。我无法将一个字符串作为参数传递给指针接收器函数以修改结构数据。有人能帮忙吗?

代码:

package main

import (
   "fmt"
)

type book struct {
    author   string
    name     string
    category string
    price    int16
}

func (b book) greet() string {
    return "Welcome " + b.author
}

func (b *book) changeAuthor(author string) {
   b.author = author
}

func main() {
    book := book{author: "Arockia",
        name:     "Python shortcuts",
        category: "IT",
        price:    1500}
    fmt.Println(book.author)
    fmt.Println(book.greet())
    fmt.Println(book.changeAuthor("arulnathan"))
    fmt.Println(book.author)
}