这是我在网站上的第一个问题。我是一名新的CS学生，需要一些可能非常简单的帮助。代码将编译。当我按程序要求输入值时，它会将值存储错误。它将存储总支付和储蓄率的正确值，但即使输入6.9，IRA费率也会恢复为100％，并且它似乎将IRA费率存储在saveAmount中。请停下来弄清楚我在这里做错了什么。
import java.text.DecimalFormat;
import java.util.*;
public class CollinDunn_1_05 {
static Scanner console = new Scanner(System.in);
static DecimalFormat formatCash = new DecimalFormat("#,###.00");
static double iraTotal = 0.0;
static double saveAmount = 0.0;
static double totalSave = 0.0;
static String line = "";
public static void main (String [] args) {
// Input variables
double grossPay = 0.0; // The gross pay from a users paycheck
double saveRate = 0.0; // This is the user entered savings rate
double iraRate= 0.0; // The IRA investment rate
String whichOne = ""; // A temp variable to pass a string type into UserInput
printInfo();
grossPay = userInput("gross pay");
saveRate = userInput("savings rate");
iraRate = userInput("IRA rate");
iraTotal = iraAmount(grossPay, iraRate);
saveAmount = savingsAmount(grossPay, saveRate);
outputResults(grossPay, saveRate, saveAmount, iraRate, iraTotal);
return;
} // End Main
public static void printInfo() {
System.out.println ("This program uses methods to calculate \n"
+ "savings amounts and IRA investment amounts \n"
+ "from user input consisiting of their gross pay, \n"
+ "their desired savings rate and IRA rate, made by "
+ " Collin Dunn");
return;
} // End ProgramInfo
public static double userInput(String whichOne) {
double saveMe = 0.0;
System.out.print("Please enter your " + whichOne + ": ");
saveMe = console.nextDouble();
return saveMe;
} // End userInput
public static double iraAmount(double grossPay, double iraRate) {
iraTotal = grossPay * (iraRate / 100.0);
return iraTotal;
} // End iraAmount
public static double savingsAmount(double grossPay, double saveRate) {
saveAmount = grossPay * (saveRate / 100.0);
return saveAmount;
} // End savingsAmount
public static void outputResults(double grossPay, double saveRate, double iraRate,
double saveAmount, double iraTotal) {
totalSave = saveAmount + iraTotal;
System.out.print ("With a gross pay of $" + formatCash.format(grossPay)
+ ", a savings rate of %" + formatCash.format(saveRate)
+ " and a IRA rate of %" +formatCash.format(iraRate)
+ ".\n Your savings amount will be $" + formatCash.format(saveAmount)
+ ", with a investment amount of $" + formatCash.format(iraTotal)
+ ".\n Which leaves you with a total savings of $" +
+ totalSave + ". Way to go for paying yourself!" );
return;
} // End outputResults
} //End Class
答案 0 :(得分：0)
您唯一的问题是您传递给outputResults()方法或已设置的参数的顺序。
将方法的签名更改为：
public static void outputResults(double grossPay, double saveRate, double saveAmount, double iraRate, double iraTotal) {
现在匹配您调用方法的方式：
outputResults(grossPay, saveRate, saveAmount, iraRate, iraTotal);
让我提出一些额外的建议：
1）您始终在方法签名中将参数命名为与全局变量相同的名称，这使得在访问方法中的变量时会产生混淆。要么避免对方法输入变量使用相同的名称，要么使用类似this.amount = amount之类的名称来使其更明显地表达您的意图。
2）除非您有正当理由使用它，否则请避免静电（这种情况非常罕见）。 相反，利用Java的面向对象特性，在main方法中创建类的实例，并在该实例上调用方法。这将使您的代码更具可读性，可靠性和可重用性。
3）在返回类型＆＃39; void＆＃39;的方法中，您不需要添加空return;语句。
为了纠正您的问题并展示我列出的要点，我已经重构了您的代码并在下面提供了它。顺便说一下，你有很大的潜力。尽管您可以改进一些细节，但作为第一年的CS学生，您的代码写得很好并且经过深思熟虑。干得好！
import java.text.DecimalFormat;
import java.util.*;
public class CollinDunn_1_05 {
DecimalFormat formatCash = new DecimalFormat("#,###.00");
double iraTotal = 0.0;
double saveAmount = 0.0;
double totalSave = 0.0;
double grossPay = 0.0; // The gross pay from a users paycheck
double saveRate = 0.0; // This is the user entered savings rate
double iraRate= 0.0; // The IRA investment rate
public CollinDunn_1_05(double gross, double saveRt, double iraRt){
this.grossPay = gross;
this.saveRate = saveRt;
this.iraRate = iraRt;
}
public void calculate(){
calcIraAmount();
calcSavingsAmount();
}
public static void main (String [] args) {
Scanner scanner = new Scanner(System.in);
printInfo();
CollinDunn_1_05 program = new CollinDunn_1_05(
userInput("gross pay", scanner),
userInput("savings rate", scanner),
userInput("IRA rate", scanner)
);
program.calculate();
program.outputResults();
} // End Main
public static void printInfo() {
System.out.println ("This program uses methods to calculate \n"
+ "savings amounts and IRA investment amounts \n"
+ "from user input consisiting of their gross pay, \n"
+ "their desired savings rate and IRA rate, made by "
+ " Collin Dunn");
return;
} // End ProgramInfo
public static double userInput(String whichOne, Scanner console) {
double saveMe = 0.0;
System.out.print("Please enter your " + whichOne + ": ");
saveMe = console.nextDouble();
return saveMe;
} // End userInput
public void calcIraAmount() {
iraTotal = grossPay * (iraRate / 100.0);
} // End iraAmount
public void calcSavingsAmount() {
saveAmount = grossPay * (saveRate / 100.0);
} // End savingsAmount
public void outputResults() {
totalSave = saveAmount + iraTotal;
System.out.print ("With a gross pay of \$" + formatCash.format(grossPay)
+ ", a savings rate of %" + formatCash.format(saveRate)
+ " and a IRA rate of %" +formatCash.format(iraRate)
+ ".\n Your savings amount will be \$" + formatCash.format(saveAmount)
+ ", with a investment amount of \$" + formatCash.format(iraTotal)
+ ".\n Which leaves you with a total savings of \$" +
+ totalSave + ". Way to go for paying yourself!" );
} // End outputResults
} //End Class