java计算器程序代码设计说明

这份Java计算器程序设计报告包含了该计算器程序的源代码和详细的设计说明。该程序实现了基本的四则运算和括号运算，并且具有良好的用户界面和错误提示功能。在设计过程中，作者采用了面向对象的编程思想，将程序分为多个类，每个类负责不同的功能。其中，Calculator类是程序的核心类，负责解析表达式并计算结果。如果你对Java编程感兴趣，这份报告可以作为一个很好的参考资料。

相关问题

java计算器程序代码

以下是一个简单的 Java 计算器程序代码，可以进行加、减、乘、除四种基本运算：

import java.util.Scanner;

public class Calculator {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("请输入第一个数：");
        double num1 = input.nextDouble();
        System.out.print("请输入第二个数：");
        double num2 = input.nextDouble();

        System.out.print("请选择运算符（+、-、*、/）：");
        char operator = input.next().charAt(0);

        double result;
        switch (operator) {
            case '+':
                result = num1 + num2;
                break;
            case '-':
                result = num1 - num2;
                break;
            case '*':
                result = num1 * num2;
                break;
            case '/':
                if (num2 == 0) {
                    System.out.println("除数不能为0！");
                    return;
                }
                result = num1 / num2;
                break;
            default:
                System.out.println("输入的运算符有误！");
                return;
        }

        System.out.println("计算结果为：" + result);
    }
}

你可以在控制台输入两个数和运算符，程序将根据运算符进行相应的计算并输出结果。注意，除法运算时需要判断除数是否为0。

java计算器程序代码gui

以下是一个简单的Java计算器GUI程序代码，它可以通过按钮事件和键盘事件进行运算：

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

public class Calculator extends JFrame implements ActionListener, KeyListener {
    private JTextField display;
    private JButton[] buttons;
    private String[] labels = {"7", "8", "9", "/", "4", "5", "6", "*", "1", "2", "3", "-", "0", ".", "=", "+"};
    private int[] widths = {100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 200, 100, 100, 100};
    private int[] heights = {100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100};

    private double result = 0;
    private String operator = "=";
    private boolean startOfNumber = true;

    public Calculator() {
        super("Calculator");
        display = new JTextField("", 12);
        display.setHorizontalAlignment(JTextField.RIGHT);
        display.setEditable(false);

        JPanel panel = new JPanel();
        panel.setLayout(new GridLayout(4, 4));

        buttons = new JButton[16];
        for (int i = 0; i < 16; i++) {
            buttons[i] = new JButton(labels[i]);
            buttons[i].addActionListener(this);
            buttons[i].addKeyListener(this);
            buttons[i].setPreferredSize(new Dimension(widths[i], heights[i]));
            panel.add(buttons[i]);
        }

        getContentPane().add(display, BorderLayout.NORTH);
        getContentPane().add(panel, BorderLayout.CENTER);

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {
        String command = e.getActionCommand();
        if (command.charAt(0) >= '0' && command.charAt(0) <= '9' || command.equals(".")) {
            if (startOfNumber == true) {
                display.setText(command);
            } else {
                display.setText(display.getText() + command);
            }
            startOfNumber = false;
        } else {
            if (startOfNumber) {
                if (command.equals("-")) {
                    display.setText(command);
                    startOfNumber = false;
                } else {
                    operator = command;
                }
            } else {
                double x = Double.parseDouble(display.getText());
                calculate(x);
                operator = command;
                startOfNumber = true;
            }
        }
    }

    public void keyTyped(KeyEvent e) {
        char keyChar = e.getKeyChar();
        if (keyChar >= '0' && keyChar <= '9' || keyChar == '.') {
            if (startOfNumber == true) {
                display.setText("" + keyChar);
            } else {
                display.setText(display.getText() + keyChar);
            }
            startOfNumber = false;
        } else if (keyChar == '+' || keyChar == '-' || keyChar == '*' || keyChar == '/') {
            if (startOfNumber) {
                if (keyChar == '-') {
                    display.setText("" + keyChar);
                    startOfNumber = false;
                } else {
                    operator = "" + keyChar;
                }
            } else {
                double x = Double.parseDouble(display.getText());
                calculate(x);
                operator = "" + keyChar;
                startOfNumber = true;
            }
        } else if (keyChar == '\n') {
            double x = Double.parseDouble(display.getText());
            calculate(x);
            operator = "=";
            startOfNumber = true;
        } else if (keyChar == '\b') {
            String text = display.getText();
            if (text.length() > 0) {
                text = text.substring(0, text.length() - 1);
                if (text.length() == 0) {
                    display.setText("");
                    startOfNumber = true;
                } else {
                    display.setText(text);
                    startOfNumber = false;
                }
            }
        }
    }

    public void keyPressed(KeyEvent e) {
    }

    public void keyReleased(KeyEvent e) {
    }

    private void calculate(double n) {
        if (operator.equals("+")) {
            result += n;
        } else if (operator.equals("-")) {
            result -= n;
        } else if (operator.equals("*")) {
            result *= n;
        } else if (operator.equals("/")) {
            result /= n;
        } else if (operator.equals("=")) {
            result = n;
        }
        display.setText("" + result);
    }

    public static void main(String[] args) {
        Calculator calculator = new Calculator();
    }
}