尝试在for循环和失败中实例化对象 [英] Trying to instantiate objects within for loop and failing

问题描述

基本上我试图创建一个新的类，只要继续变量等于Y。我遇到的问题是

  DigitalMain.java:18：不是语句
 DigitalPhoto [] class = new DigitalPhoto [9]; 
  

编译。我曾经看过ArrayLists，但是我不太确定他们是否会像我试图实现的那样实例化类。在理想的情况下，我将拥有名为class+ i的对象，并通过其内置的set方法为每个对象创建不同的值。

  //导入类$ b $的类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; 
字符串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（请输入高度）; 
 picc [i] .setHeight = Double.parseDouble（heightString）; 
 heightString = JOptionPane.showInputDialog（请输入宽度）; 
 picc [i] .setWidth = Double.parseDouble（widthString）; 
 continueQuestion = JOptionPane.showInputDialog（Height：+ picc [i] .getHeight +\\\
 Width：+ picc [i] .getWidth +\\\
 Resolution：+ picc [i]。 getResolution +\ n Compression Ratio：+ picc [i] .getCompression +\\\
 Required Storage：+ picc [i] .calcStorage（）+\\\
扫描照片的价格：+ picc [i ] .getCost（）+请输入'Y'再试一次或者'Y'来接受值。 
}; 
 
 
 
 {
 bitpsString = JOptionPane.showInputDialog（请输入您的网络连接速度，必须是1到99999999之间的整数）; 
 bitps = Double.parseDouble（bitpsString）; 
} while（bitps> 0& bitps< 99999999）; 
 picc0.setSpeed（bitps）; （y = 0; 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，您将付款：+ totesPrice +\ nRequired存储是：+ totesSize +传输所需的时间是：+ wholeDigits.format（minutes） +分钟和+ wholeDigits.format（realsec）+秒。 
 
 
 
 public static double transferTime（double totalStorage，double netSpeed）{
 double bits，seconds; 
 bits =（totalStorage * 8）; 
秒=（bits / netSpeed）; 
返回秒; 
}; 
 
  

解决方案

数组的名称。单词 class 是Java语言中的关键字，因此不能用于命名变量。您也可以像这样使用 ArrayLists ：
$ b $ pre $ List $< DigitalPhoto> photoes = new ArrayList< DigitalPhoto>（）;
做
{
DigitalPhoto photo = new DigitalPhoto（）;
heightString = JOptionPane.showInputDialog（'请输入高度'）;
photo .setHeight = double.parseDouble（heightString）;
heightString = JOptionPane.showInputDialog（'请输入宽度'）;
photo .setWidth = double.parseDouble（widthtString）;
photos.add（photo）
continueQuestion = JOptionPane.showInputDialog（'Height：'+ class [i] .getHeight +'\\\
\lWidth：'+ class [i] .getWidth +' \\\
\l分辨率：'+ class [i] .getResolution +'\\\
'\\lCompression Ratio：'+ class [i] .getCompression +'\\\
\lRequired Storage：'+ class [i] .calcStorage（）+'\\\
\l扫描照片的价格：'+ class [i] .getCost（）+'请输入Y再次尝试，或者选择Y来接受值。 $ b} while {cont.equals（Y）};

Basically I am trying to create a new class as long as the continue variable equals "Y". The problem I am having is

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

upon compile. I have looked at ArrayLists but I am not quite sure if they would instantiate classes the same way as what I am trying to achieve. In an ideal situation I would have objects with the name "class"+i, and different values for every object via their built in set methods.

// 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;
    };
}

解决方案

The issue is most likely the name of your array. The word class is a keyword in the Java language and hence cannot be used to name variables. You can also use ArrayLists like so:

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")};

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