“错误:方法main(String [])中已经定义了可变键盘". [英] "error: variable keyboard is already defined in method main(String [])"

问题描述

当我尝试运行程序时，我收到一些错误消息，主要的困扰我的是错误:方法main(String [])中已经定义了可变键盘"

I'm getting several error messages when I try to run my program, the main one which bothers me being "error: variable keyboard is already defined in method main(String [])"

我应该在程序中不止一次main(String [])，还是在刚开始时就止步?这里还有什么不对吗?

Am I supposed to but main(String []) more than once in my program, or just in the beginning as I have it? What else could be wrong here?

这是我程序的开始:

public static void main(String[]args)
{
    String firstName, lastName;
    int moviesDownloaded, stateResidency;
    double movieCost, netPayment, tax, discount, totalCharge, payment, taxRate;

    System.out.println("Enter your first name:");
    Scanner keyboard = new Scanner(System.in);
    firstName = keyboard.nextString();

    System.out.println("Enter your last name:");
    Scanner keyboard = new Scanner(System.in);
    lastName = keyboard.nextString();

    System.out.println("Enter the number of movies downloaded:");
    Scanner keyboard = new Scanner(System.in);
    moviesDownloaded = keyboard.nextInt();

    System.out.println("Enter the cost per movie:");
    Scanner keyboard = new Scanner(System.in);
    movieCost = keyboard.nextDouble();

    System.out.println("Indicate your state of residency. Enter 1 for Mississippi or 2 for any other state.");
    Scanner keyboard = new Scanner(System.in);
    stateResidency = keyboard.nextInt();

推荐答案

您只应声明并初始化一次键盘，然后再使用它.因此，请删除以下类型的所有行: Scanner keyboard = new Scanner(System.in); .否则，您将尝试多次声明同一变量，因此java会抱怨.

You should only declare and initialize keyboard once and then use it. So remove all lines of the type: Scanner keyboard = new Scanner(System.in); apart from the first one. Otherwise you try to declare the same variable multiple times and thus java complains.

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