Else没有如果错误：我不明白为什么java不能识别我的if语句 [英] Else without if error: I dont understand why java isn't recognizing my if statment

问题描述

在第53行，它给我一个错误的else没有if。我明显有一个if语句，但我不知道我做错了，使java不能识别它。我试着绕过花括号，没有什么工作。

  import java.util.Scanner; 
 import java.text.DecimalFormat; 
 
 public class Quiz6 
 {
 
 public static void displayInfo（）
 {
 System.out.println（
 \\\
\tAuthor：Allen Watson \\\
+ 
\tClass：\tCSCI 1250-001 \\\
+ 
\tDate：\t10 / 09/2013 \\\
+ 
\tLab：\tQuiz6 \\\
）; 
} 
 
 public static double calculatePay（int hourWorked，double hourlyRate）
 {
 double dPay; 
 dPay =（hourWorked * hourlyRate）; 
 return dPay; 
} 
 
 public static void main（String [] args）
 {
 Scanner Keyboard = new Scanner（System.in）; 
 DecimalFormat dfMoney = new DecimalFormat（$＃，## 0.00）; 
 String strName; 
 int iCount; 
 int iDaysWorked; 
 int iTotalHoursWorked; 
 int iSingleDayHours; 
 double dHourlyRate; 
 final byte WEEK = 7; 
 
 displayInfo（）; 
 
 System.out.print（\tWhat是你的名字：）; 
 strName = Keyboard.nextLine（）; 
 System.out.print（\\\
\t这个星期你工作了多少天：）; 
 iDaysWorked = Keyboard.nextByte（）; 
 System.out.print（\\\
\t你做了多少时间：）; 
 dHourlyRate = Keyboard.nextDouble（）; 
 
 if（dDaysWorked< = WEEK）; 
 {
 for（iCount = 1; iCount <= iDaysWorked; iCount ++）
 {
 System.out.print（\t您在当天工作多少小时+ iCount +：）; 
 iSingleDayHours = Keyboard.nextInt（）; 
 iSingleDayHours + = iTotalHoursWorked; 
} 
} 
 else 
 {
 bDaysWorked = 0; 
 System.out.print（一周只能有七天）; 
} 
 
 calculatePay（iTotalHoursWorked，dHourlyRate）; 
 
 System.out.print（Hello+ strName +，您在+ iDaysWorked +天内总共工作了+ iTotalHoursWorked +小时。 
 System.out.print（\\\
W小时费率+ dfMoney（dHourlyRate）+你做+ dfMoney（dPay）+。 
 
} 
} 
  

解决方案

这里有问题：

  if（dDaysWorked< = WEEK）; // 去除 ; 
  

尾随; if 语句完成后， {} / code>条件，因此 else 部分在其前面没有匹配 if b
$ b

这是一个相当频繁的错误，很难找到。如果它不是 else 块，代码将正确编译，但它是错误的。底线：从不，在的开始行中，如果，的时候放置; 或和语句。

At line 53 it is giving me an error of else without if. I clearly have an if statement, but i don't know what i'm doing wrong to make java not recognize it. I've tried moving around the braces and nothing is working.

import java.util.Scanner;
import java.text.DecimalFormat;

public class Quiz6
{

    public static void displayInfo()
    {
        System.out.println(
                            "\n\tAuthor: Allen Watson \n" +
                            "\tClass: \tCSCI 1250-001 \n" +
                            "\tDate: \t10/09/2013 \n" +
                            "\tLab: \tQuiz6 \n");
    }

    public static double calculatePay(int hourWorked, double hourlyRate)
    {
        double dPay;
        dPay = (hourWorked * hourlyRate);
        return dPay;
    }

    public static void main(String[] args)
    {
        Scanner Keyboard = new Scanner(System.in);
        DecimalFormat dfMoney = new DecimalFormat("$#,##0.00");
        String strName;
        int iCount;
        int iDaysWorked;
        int iTotalHoursWorked;
        int iSingleDayHours;
        double dHourlyRate;
        final byte WEEK = 7;

        displayInfo();

        System.out.print("\tWhat is your name: ");
        strName = Keyboard.nextLine();
        System.out.print("\n\tHow many days did you work this week: ");
        iDaysWorked = Keyboard.nextByte();
        System.out.print("\n\tHow much do you make an hour: ");
        dHourlyRate = Keyboard.nextDouble();

        if(dDaysWorked <= WEEK);
        {
            for(iCount = 1; iCount <= iDaysWorked ; iCount++)
            {
                System.out.print("\tHow many hours did you work on the day"+iCount+":");
                iSingleDayHours = Keyboard.nextInt();
                iSingleDayHours += iTotalHoursWorked;
            }   
        }
        else
        {
            bDaysWorked = 0;
            System.out.print("A week can only have seven days");
        }

        calculatePay(iTotalHoursWorked,dHourlyRate);

        System.out.print("Hello "+strName+", you worked a total of "+iTotalHoursWorked+" hours over "+iDaysWorked+" days.");
        System.out.print("\nWith am hourly rate of "+dfMoney(dHourlyRate)+" you made "+dfMoney(dPay)+".");

    }
}

解决方案

Here's the problem:

if(dDaysWorked <= WEEK); // remove the ;

That trailing ; is making Java believe that the if statement is finished, and the {} block after it is outside the if condition, consequently the else part has no matching if preceding it.

This is a rather frequent bug, and a hard one to spot. If it weren't for the else block, the code would have compiled correctly, but it would have been wrong. Bottom line: never, ever put a ; in the opening line of an if, for or while statement.

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