-1

基本上，只要 continue 变量等于“Y”，我就会尝试创建一个新类。我遇到的问题是

DigitalMain.java:18: not a statement
    DigitalPhoto[] class = new DigitalPhoto[9];

编译时。我看过 ArrayLists 但我不太确定它们是否会以与我试图实现的相同的方式实例化类。在理想情况下，我将拥有名称为“class”+i 的对象，并通过其内置的 set 方法为每个对象提供不同的值。

// Import classes for class
import java.util.Arrays;
import java.util.List;
import javax.swing.*;
import java.awt.event.*;
import java.text.DecimalFormat;

public class DigitalMain
{
  public static void main(String args[])
  {
    String cont = "Y";
    String heightString,widthString,width,bitpsString;
    double bitps,x,y,totesPrice,totesSize,totesSpeed;
    DecimalFormat wholeDigits = new DecimalFormat("0");
    DecimalFormat dec = new DecimalFormat("0.00");

    DigitalPhoto[] picc = new DigitalPhoto[20];
    for(int i=0; cont.equals("Y") ; i++)
    {
    picc[i] = new DigitalPhoto();
    heightString = JOptionPane.showInputDialog("Please enter height");
    picc[i].setHeight = Double.parseDouble(heightString);
    heightString = JOptionPane.showInputDialog("Please enter width");
    picc[i].setWidth = Double.parseDouble(widthString);
    continueQuestion = JOptionPane.showInputDialog("Height: " + picc[i].getHeight + "\n Width: " + picc[i].getWidth + "\n Resolution: " + picc[i].getResolution + "\n Compression Ratio: " + picc[i].getCompression + "\n Required Storage: " + picc[i].calcStorage() + "\n Price of Scanned Photo: " + picc[i].getCost() + "Please enter 'Y' to try again or anything but 'Y' to accept values.");
    };


    do
    {
    bitpsString = JOptionPane.showInputDialog("Please enter your internet connection speed. Must be an integer between 1 and 99999999");
    bitps = Double.parseDouble(bitpsString);
    } while (bitps > 0 && bitps < 99999999);
    picc0.setSpeed(bitps);

    for(y = 0; y<picc.length; y++) {
      totesPrice += picc+y.getCost();
      totesSize += picc+y.calcStorage();
      totesSpeed = picc0.getSpeed();
    }

    double seconds = transferTime(totesSize, totesSpeed);
    double minutes = seconds / 60;
    double realsec = seconds % 60;

    JOptionPane.showMessageDialog(null, "You will be paying: " + totesPrice + "\nRequired Storage is: " + totesSize + "Required time for transfer is: " + wholeDigits.format(minutes) + " minutes, and " + wholeDigits.format(realsec) + " seconds.");

  }

  public static double transferTime(double totalStorage, double netSpeed) {
    double bits, seconds;
    bits = (totalStorage * 8);
    seconds = (bits / netSpeed);
    return seconds;
    };
}
4

4 回答 4

3

class是一个关键字 - 您不能将其用作变量名。

此外，您在这里有一个奇怪的构造：

for(int i=0; cont.equals("Y") ; i++)
{
    ...
} while {continue.equalsIgnoreCase(Y)};

没有“for/while”循环之类的东西 - 有一个普通for循环、一个while循环和一个do/while循环。

所以你实际上有一个for循环，后面跟着一个无效while循环。它没有条件。

你需要弄清楚你想要什么。（可能是一个包含do/while 循环的 for 循环，尽管我会将内部循环提取到一个单独的方法中。通常，您的代码会从分解为多个方法中受益匪浅。

您稍后会执行类似的操作，尽管这次使用do/ while：

do
{
    ...
} while {bitps > 0 && bitps < 99999999};

while循环的条件放在圆括号中，而不是大括号中：

do
{
    ...
} while (bitps > 0 && bitps < 99999999);

基本上，您应该阅读可用于循环的语法选项。

于 2012-04-30T05:21:48.870 回答
1

问题很可能是您的阵列的名称。该词class是 Java 语言中的关键字，因此不能用于命名变量。你也可以ArrayLists像这样使用：

List<DigitalPhoto> photoes = new ArrayList<DigitalPhoto>(); 
do
    {
    DigitalPhoto photo = new DigitalPhoto();
    heightString = JOptionPane.showInputDialog('Please enter height');
    photo .setHeight = double.parseDouble(heightString);
    heightString = JOptionPane.showInputDialog('Please enter width');
    photo .setWidth = double.parseDouble(widthtString);
    photos.add(photo)
    continueQuestion = JOptionPane.showInputDialog('Height: ' + class[i].getHeight + '\n\lWidth: ' + class[i].getWidth + '\n\l Resolution: ' + class[i].getResolution + '\n\lCompression Ratio: ' + class[i].getCompression + '\n\lRequired Storage: ' + class[i].calcStorage() + '\n\lPrice of Scanned Photo: ' + class[i].getCost() + 'Please enter "Y" to try again or anything but "Y" to accept values.')
    } while {cont.equals("Y")};
于 2012-04-30T05:24:37.463 回答
1

您正在使用什么样的循环。

for(...)
{
...
}while();

没有for-while循环。

而且你的for循环条件永远不会变成假的。为您的 for 循环设置适当的条件。您的循环
中也存在语法错误。for-whileIE。最后声明

continueQuestion = JOptionPane.showInputDialog('Height: ' + class[i].getHeight + '\n\lWidth: ' + class[i].getWidth + '\n\l Resolution: ' + class[i].getResolution + '\n\lCompression Ratio: ' + class[i].getCompression + '\n\lRequired Storage: ' + class[i].calcStorage() + '\n\lPrice of Scanned Photo: ' + class[i].getCost() + 'Please enter "Y" to try again or anything but "Y" to accept values.') // you miss the ;
于 2012-04-30T05:38:42.943 回答
0

变量命名有一些规则 

 You cannot use any of the following(in list of keywords) as identifiers in your
 programs.The keywords const and goto are reserved, even though they are not 
 currently used. true, false, and null might seem like keywords, but they 
 are actually literals;      you cannot use them as identifiers in your programs.

关键字列表

for(int i=0; cont.equals("Y") ; i++)
 {
   class[i] = new DigitalPhoto();
   heightString = JOptionPane.showInputDialog('Please enter height');
   class[i].setHeight = double.parseDouble(heightString);
   heightString = JOptionPane.showInputDialog('Please enter width');
   class[i].setWidth = double.parseDouble(widthtString);
   continueQuestion = JOptionPane.showInputDialog('Height: ' + 
   class[i].getHeight + '\n\lWidth: ' + class[i].getWidth + '\n\l Resolution: ' +
   class[i].getResolution + '\n\lCompression Ratio: ' +  class[i].getCompression +
  '\n\lRequired Storage: ' + class[i].calcStorage() + '\n\lPrice of Scanned Photo: ' + 
    class[i].getCost() + 'Please enter "Y" to 
   try again or anything but "Y" to accept values.')
} while {continue.equalsIgnoreCase(Y)};

在这里我不知道任何循环for-while..只需检查一些基础知识..
java 中的循环

于 2012-04-30T05:43:49.933 回答