java - 如何区分java计算器中的第一个int和第二个int？

Question

我正在使用 MVC 风格制作一个 Java 计算器。我只是无法区分他们输入的第一个数字和第二个数字。我输入了一个 boolean 值，当输入加号或减号时，该 boolean 值变为 true，这会将数字字符串更改回“”，即空白字符串。但是当这个 boolean 值为真时我去获取它时，字符串已经是空白的，所以为时已晚。关于如何获取第一个数字和第二个数字有什么建议吗？这个计算器只是使用加号和减号。带有等于和清除按钮。谢谢

计算类

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;


class Calc extends JFrame implements ActionListener {


    private JTextField numDisplay = new JTextField(10);
    private JButton plusButton = new JButton("+");
    private JButton minusButton = new JButton("-");
    private JButton clearButton = new JButton("Clear");
    private JButton equalsButton = new JButton("=");
    private JButton zeroButton = new JButton("0");
    private JButton oneButton = new JButton("1");
    private JButton twoButton = new JButton("2");
    private JButton threeButton = new JButton("3");
    private JButton fourButton = new JButton("4");
    private JButton fiveButton = new JButton("5");
    private JButton sixButton = new JButton("6");
    private JButton sevenButton = new JButton("7");
    private JButton eightButton = new JButton("8");
    private JButton nineButton = new JButton("9");
    private String number = "";
    private boolean trueFalse;   //plus or minus
    private boolean onOff = false;   //false = 1st int, true = 2nd int
    private int total;
    private boolean isEquals = false;   // false = haven't clicked equals button yet,     true they have
    //private String numberText;

    Calc(){
        JPanel calcPanel = new JPanel();

        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setSize(400, 600);
        calcPanel.add(numDisplay);
        calcPanel.add(plusButton);
        calcPanel.add(minusButton);
        calcPanel.add(clearButton);
        calcPanel.add(equalsButton);
        calcPanel.add(zeroButton);
        calcPanel.add(oneButton);
        calcPanel.add(twoButton);
        calcPanel.add(threeButton);
        calcPanel.add(fourButton);
        calcPanel.add(fiveButton);
        calcPanel.add(sixButton);
        calcPanel.add(sevenButton);
        calcPanel.add(eightButton);
        calcPanel.add(nineButton);

        this.add(calcPanel);

        plusButton.addActionListener(this);
        minusButton.addActionListener(this);
        clearButton.addActionListener(this);
        equalsButton.addActionListener(this);
        zeroButton.addActionListener(this);
        oneButton.addActionListener(this);
        twoButton.addActionListener(this);
        threeButton.addActionListener(this);
        fourButton.addActionListener(this);
        fiveButton.addActionListener(this);
        sixButton.addActionListener(this);
        sevenButton.addActionListener(this);
        eightButton.addActionListener(this);
        nineButton.addActionListener(this);

    }
    public void actionPerformed(ActionEvent event){
        if (event.getSource() instanceof JButton){
            JButton clickedButton = (JButton) event.getSource();
            String buttonText = clickedButton.getText();
            if (clickedButton == zeroButton || clickedButton == oneButton || clickedButton == twoButton || clickedButton == threeButton || clickedButton == fourButton || clickedButton == fiveButton || clickedButton == sixButton || clickedButton == sevenButton || clickedButton == eightButton || clickedButton == nineButton)
            {
                number = number + buttonText;
            }
            if (clickedButton == clearButton){
                number = "";
                onOff = false;
            }
            if (clickedButton == plusButton){
                trueFalse = true;
                onOff = true;
            }
            if (clickedButton == minusButton){
                trueFalse = false;
                onOff = true;
                number = "";
            }
            if (clickedButton == equalsButton){
                isEquals = true;
            }
        }
    }
    public int getNumber(){
        return Integer.parseInt(number);
    }
    public boolean trueFalse(){
        return trueFalse;
    }
    public boolean onOff(){
        return onOff;
    }
    public int total(){
        return total;
    }
    public boolean isEquals(){
        return isEquals;
    }
    public String getNumberString(){
        return number;
    }
}

计算类

public class Calculations
{
    private Calc theView;
    private CalculationModel theModel;
    private boolean onOff = theView.onOff();
    private boolean trueFalse = theView.trueFalse();
    private int number1;

    public Calculations(Calc theView, CalculationModel theModel)
    {
        this.theView = theView;
        this.theModel = theModel;
    }

    public void doesometing() {
        if(trueFalse)     
        {
            number1 = theView.getNumber();
        }
    }   
}

Answer 1

处理用户输入的一种方法是将用户输入的值压入堆栈。这样他的最新值就排在最后。

要进行计算，您需要从堆栈中弹出两个值，运行计算并将结果压入堆栈。输入的下一个值将在最后一个结果之后进入堆栈。

编辑:收集数字以生成数字可以通过将数字附加到字符串末尾并在按下非数字时将字符串转换为数字来完成。请注意，连续的两个点不是有效数字，因此您需要处理它。