计算器加减乘除取余等的实现k1

calculator.java

@@ -1,48 +1,155 @@
-import java.util.Scanner;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import javax.swing.*;
 
-public class calculator {
-    public static void main(String[] args) {
-        Scanner scanner = new Scanner(System.in);
-
-        System.out.print("请输入第一个数:");
-        double num1 = scanner.nextDouble();
-
-        System.out.print("请输入第二个数:");
-        double num2 = scanner.nextDouble();
-
-        System.out.print("请选择操作符 (+, -, *, /, %):");
-        String operation = scanner.next();
-
-        double result;
-        switch (operation) {
-            case "+":
-                result = num1 + num2;
-                break;
-            case "-":
-                result = num1 - num2;
-                break;
-            case "*":
-                result = num1 * num2;
-                break;
-            case "/":
-                if (num2 == 0) {
-                    System.out.println("错误：除数不能为0");
-                    return;
-                }
-                result = num1 / num2;
-                break;
-            case "%":
-                if (num2 == 0) {
-                    System.out.println("错误：除数不能为0");
-                    return;
+public class calculator extends JFrame implements ActionListener {
+
+    private JTextField display;
+    private String equation = "";
+    private boolean newNumber = true;
+
+    public calculator() {
+        setTitle("简易计算器");
+        setSize(300, 400);
+        setDefaultCloseOperation(EXIT_ON_CLOSE);
+        setLayout(new BorderLayout());
+
+        // 增加结果显示区域的高度
+        display = new JTextField("0");
+        display.setEditable(false);
+        display.setHorizontalAlignment(JTextField.RIGHT);
+        display.setFont(new Font("Arial", Font.BOLD, 24));
+        display.setPreferredSize(new Dimension(300, 60));
+        add(display, BorderLayout.NORTH);
+
+        JPanel panel = new JPanel();
+        panel.setLayout(new GridLayout(5, 4)); // 增加一行用于放置清除按钮
+
+        String[] buttons = {
+                "7", "8", "9", "/",
+                "4", "5", "6", "*",
+                "1", "2", "3", "-",
+                "0", ".", "=", "+",
+                "C" // 清除按钮
+        };
+
+        for (String label : buttons) {
+            JButton button = new JButton(label);
+            button.setFont(new Font("Arial", Font.BOLD, 18));
+            button.addActionListener(this);
+            panel.add(button);
+        }
+
+        add(panel, BorderLayout.CENTER);
+        setLocationRelativeTo(null); // 居中显示
+    }
+
+    @Override
+    public void actionPerformed(ActionEvent e) {
+        String command = e.getActionCommand();
+
+        if ("0123456789.".indexOf(command) >= 0) {
+            if (newNumber) {
+                display.setText(command);
+                newNumber = false;
+            } else {
+                display.setText(display.getText() + command);
+            }
+        } else if ("+-*/%".indexOf(command) >= 0) {
+            equation = display.getText() + command;
+            display.setText("0");
+            newNumber = true;
+        } else if (command.equals("=")) {
+            try {
+                equation += display.getText();
+                double result = eval(equation);
+                // 检查结果是否为整数
+                if (result == (long) result) {
+                    display.setText(String.valueOf((long) result));
+                } else {
+                    display.setText(String.valueOf(result));
                 }
-                result = num1 % num2;
-                break;
-            default:
-                System.out.println("无效的操作符");
-                return;
+                newNumber = true;
+            } catch (Exception ex) {
+                display.setText("Error");
+            }
+        } else if (command.equals("C")) {
+            display.setText("0");
+            equation = "";
+            newNumber = true;
         }
+    }
+
+    private double eval(final String str) {
+        return new Object() {
+            int pos = -1, ch;
 
-        System.out.printf("结果是: %.2f\n", result);
+            void nextChar() {
+                ch = (++pos < str.length()) ? str.charAt(pos) : -1;
+            }
+
+            boolean eat(int charToEat) {
+                while (ch == ' ') nextChar();
+                if (ch == charToEat) {
+                    nextChar();
+                    return true;
+                }
+                return false;
+            }
+
+            double parse() {
+                nextChar();
+                double x = parseExpression();
+                if (pos < str.length()) throw new RuntimeException("Unexpected: " + (char)ch);
+                return x;
+            }
+
+            double parseExpression() {
+                double x = parseTerm();
+                for (;;) {
+                    if      (eat('+')) x += parseTerm(); // addition
+                    else if (eat('-')) x -= parseTerm(); // subtraction
+                    else return x;
+                }
+            }
+
+            double parseTerm() {
+                double x = parseFactor();
+                for (;;) {
+                    if      (eat('*')) x *= parseFactor(); // multiplication
+                    else if (eat('/')) x /= parseFactor(); // division
+                    else return x;
+                }
+            }
+
+            double parseFactor() {
+                if (eat('+')) return parseFactor(); // unary plus
+                if (eat('-')) return -parseFactor(); // unary minus
+
+                double x;
+                int startPos = this.pos;
+                if (eat('(')) { // parentheses
+                    x = parseExpression();
+                    eat(')');
+                } else if ((ch >= '0' && ch <= '9') || ch == '.') { // numbers
+                    while ((ch >= '0' && ch <= '9') || ch == '.') nextChar();
+                    x = Double.parseDouble(str.substring(startPos, this.pos));
+                } else {
+                    throw new RuntimeException("Unexpected: " + (char)ch);
+                }
+
+                if (eat('^')) x = Math.pow(x, parseFactor()); // exponentiation
+                return x;
+            }
+        }.parse();
+    }
+
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(() -> {
+            calculator calc = new calculator();
+            calc.setVisible(true);
+        });
     }
 }
+