Question

整个代码非常简单，从之前的项目中我们或多或少地将其转换为使用方法。基本上它会提示用户输入他们的姓名，工作时间和工资率，获取该信息并计算净工资。我已经写了大部分代码，根据我的理解，它工作正常。

现在回答我的问题。一种方法必须在屏幕上打印一条消息，我必须在程序开始时调用该方法一次，打印一条欢迎消息，并在程序结束时打印一条感谢信息。有了这个，我迷失了如何制作它，所以一个方法可以确定它何时是程序的结束。（当用户在提示输入其名称时输入-1时，程序将结束。）

package project.pkg2;

import java.util.*;

public class Project2 {

// Scanner for the console inputs
static Scanner console = new Scanner (System.in);

public static void main(String[] args) {

    String name, formatNet;
    double hours, pay, netPay;

 // Prints the welcome message from the method.
    welcomeMessage();

 // Every initialized variable receives the return statements from their respected methods.        
    name  = getName();

    while (!(name.equals("-1")))
    {
    pay   = getPay ();
    hours = getHours ();
    netPay = calcNet(pay,hours);

 // Formats the net pay to be 2 decimals.   
    formatNet = String.format("%.2f", netPay);
    System.out.println(name + "'s net pay is $" + formatNet + " \n");}

// Method for the welcome message, a void because it returns no values.
}
static void welcomeMessage ()
{
    System.out.println("Welcome to the CIS 220 Payroll Calculator!\n");
}

// Method that prompts the user to enter their name, scans it, then returns it.
static String getName ()
{
    String name;
    System.out.println("Please enter the employee's name(Enter a -1 when finished): ");
    name = console.nextLine();
    return name;

}

//Method that prompts the user to enter their pay rate, scans it, then returns it.    
static double getPay()
{
    double payRate;
    System.out.println("Please enter the employee's pay rate: ");
    payRate = console.nextDouble();
    console.nextLine();
    return payRate;
}

//Method that prompts the user to enter their hours worked, scans it, then returns it.        
static double getHours ()
{
    double hours;
    System.out.println("Please enter the employee's hours worked:");
    hours = console.nextDouble();
    console.nextLine();
    return hours;
}

//Method that uses the pay rate, hours worked that the user has entered.
//determines if the user qualifies for overtime pay or not, then calculates the overall    pay
//followed by tax reduction, then returns the netpay value.
static double calcNet (double pay, double hours)
{
   double net, grossPay;
   String formatNet;

    if(hours > 40)
    {
        grossPay = (pay * hours) * 1.5;
    }
    else
    {
        grossPay = pay * hours;
    }
    net = grossPay - (grossPay * .15);
    return net;
}


}

Answer 1

你可以使你的printMessage方法（从welcomeMessage重命名）采用一个布尔参数来告诉方法它是否应该显示欢迎或感谢信息。

static void printMessage(final boolean isStarting) {
    if(isStarting) {
        // print the welcome message
        ...
    } else {
        // print the thank you message
        ...
    }
}

然后在程序开头使用true调用方法，最后使用false调用方法。

或者你可以有一个类变量：

private boolean hasPrintedWelcome = false;

printMessage方法将是：

static void printMessage(final boolean isStarting) {
    if(!hasPrintedWelcome) {
        // print the welcome message
        ...
        hasPrintedWelcome = true;
    } else {
        // print the thank you message
        ...
    }
}

第一次调用printMessage方法时，它将显示欢迎消息。然后第二次调用该方法，以及随后的任何时间，该方法将显示感谢信息。

Answer 2

您的程序存在一个问题：在进入while循环之前，您要求员工的姓名，因此名称将只设置一次并且永远不会更改，因此你会有一个无限循环。

您需要做的是在循环结束时再调用getName()，以允许用户设置新名称，然后退出循环：

// Every initialized variable receives the return statements from their respected methods. name = getName(); while (!(name.equals("-1"))) { pay = getPay (); hours = getHours (); netPay = calcNet(pay,hours); // Formats the net pay to be 2 decimals. formatNet = String.format("%.2f", netPay); System.out.println(name + "'s net pay is $" + formatNet + " \n"); // Ask for the employee's name again name = getName(); } // Call the method to show the exit message here, like that: exitMessage();

一旦你修复了它，你就可以在while循环之后调用显示退出消息的方法。

编辑：似乎我误解了这个问题，无限循环只是一个错误而不是实际问题，请参阅另一个答案。

Java方法，打印欢迎消息，然后是感谢信息

2 个答案: