我有一种感觉我的问题出现在checkValidity方法的if语句中，但是我无法弄清楚我到底出错的地方。
这里是文件中使用的数据值
很抱歉，如果值看起来很紧凑
戴尔：戴尔公司125 25.567 0.025 28.735 0.025
MSFT：Microsoft
34.1 -15.75 0.012 15.90 0.013
GOOG：谷歌
56.5 58.125 0.032 67.975 0.030
IBM：IBM Corp
87.3 8.875 0.015 7.500 0.020
DTLK：DataLink
345 23.250 0.055 25.750 0.050
CSCO：思科
90 14.570 1.025 16.890 1.024
INTC：英特尔
89.1 78.120 0.042 99.355 0.042
BGUS：Bogus Corp
0 25.567 0.012 25.678 0.023
import java.util.Scanner;
import java.text.DecimalFormat;
import java.io.*;
public class Profit
{
public static void main(String[] args) throws IOException
{
String input; //string for input from opened file
//Boolean TFStatement; //true/ false statement for validity
int shares = 0; //number of stocks
String company; //name of the company
double sellPrice = 0; //sell price per stock
double buyPrice = 0; //purchase price per stock
double sellTotal = 0; //selling total w/o factoring in commission amount
double buyTotal = 0; //purchase total w/o factoring in buying commission amount
double sellCommissionPercentage = 0; //commission percentage for selling the stock
double buyCommissionPercentage = 0; //commission percentage for buying the stock
double profit = 0; //total profit after buying and selling stocks
double buyCommission = 0; //total purchase commission amount
double sellCommission = 0; //total selling commission amount
DecimalFormat formatPercent = new DecimalFormat("$#,##0.00%"); //format of currency for the profit
//Scanner for keyboard input
Scanner keyboard = new Scanner(System.in);
//Get file
System.out.print("Sean Harris\n\n" + "File name: ");
String filename = keyboard.nextLine();
//Open file
File stockFile = new File(filename);
Scanner inputFile = new Scanner(stockFile);
//loop until fils has no more lines to read
while (inputFile.hasNext())
{
company = inputFile.nextLine();
shares = inputFile.nextInt();
buyPrice = inputFile.nextDouble();
buyCommissionPercentage = inputFile.nextDouble();
sellPrice = inputFile.nextDouble();
sellCommissionPercentage = inputFile.nextDouble();
if (checkValidity(company, shares, buyPrice, buyCommissionPercentage, sellPrice, sellCommissionPercentage) == (false))
calcProfit(shares, buyPrice, buyCommissionPercentage, sellPrice, sellCommissionPercentage, profit, buyCommission, sellCommission, sellTotal, buyTotal);
display(company, profit);
}
}
/**
Check if the info in the file is valid
*/
public static boolean checkValidity(String theCompany,int theShares, double theBuyPrice, double theBuyCommissionPercentage, double theSellPrice, double theSellCommissionPercentage)
{
//checking all of the values to see if they are valid
Boolean TFStatement;
TFStatement = (theShares <= 0 || theBuyPrice < 0 || theBuyCommissionPercentage < 0 || theBuyCommissionPercentage > .20 || theSellCommissionPercentage < 0 || theSellCommissionPercentage > .20 || theSellPrice < 0 ? true : false);
/*
if (theShares <= 0 || theBuyPrice < 0 || theBuyCommissionPercentage < 0 || theBuyCommissionPercentage > .20 || theSellCommissionPercentage < 0 || theSellCommissionPercentage > .20 || theSellPrice < 0)
TFStatement = true;
else
TFStatement = false;
*/
//displaying the invalid message if a value is invalid
if (theShares <= 0)
System.out.println(theCompany);
System.out.println("Number of shares invalid: " + theShares);
if (theBuyPrice < 0)
System.out.println(theCompany);
System.out.println("Purchase price invalid: " + theBuyPrice);
if (theBuyCommissionPercentage < 0 || theBuyCommissionPercentage > .20)
System.out.println(theCompany);
System.out.println("Purchase commission percent invalid: " + theBuyCommissionPercentage);
if (theSellPrice < 0)
System.out.println(theCompany);
System.out.println("Sales price invalid: " + theSellPrice);
if (theSellCommissionPercentage < 0 || theSellCommissionPercentage > .20)
System.out.println(theCompany);
System.out.println("Sales commission percent invalid: " +theSellCommissionPercentage);
return TFStatement;
}
/**
Calculate profit
*/
public static double calcProfit(int theShares, double theBuyPrice, double theBuyCommissionPercentage, double theSellPrice, double theSellCommissionPercentage, double theProfit, double theBuyCommission, double theSellCommission, double theSellTotal, double theBuyTotal)
{
//getting the total price of shares sold and bought
//then figure out commission
//then use the four values to calculate profit
theSellTotal = theSellPrice * theShares;
theBuyTotal = theBuyPrice * theShares;
theSellCommission = theSellTotal * theSellCommissionPercentage;
theBuyCommission = theBuyTotal * theBuyCommissionPercentage;
theProfit = (theSellTotal - theSellCommission) - (theBuyTotal + theBuyCommission);
return theProfit;
}
/**
Display company name and profit
*/
public static void display(String theCompany, double theProfit)
{
System.out.println(theCompany);
System.out.println(theProfit);
}
}
答案 0 :(得分：0)
以此声明为例：
//displaying the invalid message if a value is invalid
if (theShares <= 0)
System.out.println(theCompany);
System.out.println("Number of shares invalid: " + theShares);
也许你来自Python背景，但在Java中，缩进并不表示嵌套。它只是一个可读性辅助工具。 if中唯一的语句是紧随其后的语句。在这种情况下：System.out.println(theCompany);。
如果您希望多个语句属于同一个if，则必须将它们放在花括号中，使它们成为“复合语句”：
if (theShares <= 0) {
System.out.println(theCompany);
System.out.println("Number of shares invalid: " + theShares);
}
这适用于代码中所有类似的if语句。
另一个，无关，请注意：
将布尔值与false进行比较没有意义。相当于
if ( checkValidity(...) == (false) ) ...
简单地说：
if ( ! checkValidity() ) ...
本身并不是错误，但它的可读性较差。布尔可以在条件下直接使用。
出于同样的原因，表达式如下：
condition1 || condition2 || condition3 ? true : false
多余。它只相当于
condition 1 || condition2 || condition3
再次 - 这没有错，只是不可读。布尔值是布尔值。