从未使用此预订值 (SA4006)

Question

我正在尝试学习 Golang，因为我正在与 Nana 一起使用 Techworld 在 Youtube 上做一个教程，并学习使用函数对逻辑进行分组，它显示了一个之前不存在的错误，并且它没有在视频中显示给她。

bookTicket(remainingTickets, userTickets, bookings, firstName, lastName, email, conferenceName)

以上是对以下函数的调用：

func bookTicket(remainingTickets uint, userTickets uint, bookings []string, firstName string, lastName string, email string, conferenceName string) {

remainingTickets = remainingTickets - userTickets

bookings = append(bookings, firstName+" "+lastName)

它说“这个预订价值从未使用过（SA4006）”

所以，这里是整个代码：

https://go.dev/play/p/GFMR7f64li1

package main

import (

    "fmt"

    "strings"

)

func main() {

    conferenceName := "Go Conference"

    const conferenceTickets int = 50

    var remainingTickets uint = 50

    bookings := []string{}

    greetUsers(conferenceName, conferenceTickets, remainingTickets)

    for {

        firstName, lastName, email, userTickets := getUserInput()

        isValidName, isValidEmail, isValidTicketNumber := validateUserInput(firstName, lastName, email, userTickets, remainingTickets)

        if isValidName && isValidEmail && isValidTicketNumber {

            bookTicket(remainingTickets, userTickets, bookings, firstName, lastName, email, conferenceName)

            firstNames := getFirstNames(bookings)

            fmt.Printf("The first name of our bookings are: %v\n", firstNames)

            if remainingTickets == 0 {

                // sair do loop/programa

                fmt.Println("Our conference is booked out. Come back next year.")

                break

            }

        } else {

            if !isValidName {

                fmt.Println("First name or last name too short.")

            }

            if !isValidEmail {

                fmt.Println("E-mail doesn't contain @ sign.")

            }

            if !isValidTicketNumber {

                fmt.Println("Number of tickets entered is invalid.")

            }

        }

    }

}

Answer 1

因此，我对代码进行了一些清理，现在它又按预期工作了。现在作为包级别变量bookings在外部并且它可以工作。mainpackage mainimport (    "fmt"    "strings")const conferenceTickets int = 50var conferenceName = "Go Conference"var remainingTickets uint = 50var bookings = []string{}现在的bookTickets电话是：bookTicket(userTickets, firstName, lastName, email)调用函数：func bookTicket(userTickets uint, firstName string, lastName string, email string) {    remainingTickets = remainingTickets - userTickets    bookings = append(bookings, firstName+" "+lastName)    fmt.Printf("Thank you %v %v for booking %v tickets. You will receive a confirmation email at %v\n", firstName, lastName, userTickets, email)    fmt.Printf("%v tickets remaining for the %v.\n", remainingTickets, conferenceName)}多谢你们。

Answer 2

与大多数其他主流语言不同，如果你不使用变量的值做某事，Go 就不允许使用变量。因此，在测试代码中解决这个问题的方法是将值打印到控制台。在最后添加这一行：fmt.Println(bookings)