用java编写简单计算器(用java编写简单计算器两个数运算gui)

概述

Java是一种通用性高的编程语言，适用于各种应用程序的开发，其中包括计算器应用程序。Java编写的简单计算器可以接受用户输入的数字和运算符，并输出计算结果。它可以进行加减乘除运算，还可以进行各种数学运算，如求平方根、计算三角函数等。本文将介绍如何用Java编写简单计算器。

步骤

制作简单计算器的第一步是设计它的界面。界面可以使用Java Swing类库，它是一个Java图形用户界面工具包。通过这个工具包，可以轻松创建按钮、文本框和标签等控件。

接下来是编写计算器的逻辑。计算器的逻辑包括接收用户输入、执行计算和输出结果。Java可以通过Scanner类接收用户输入并将其转换成数字和运算符。通过switch语句可以执行相应的计算，并将结果存储在变量中。最后，可以将结果输出到文本框中。

示例代码

下面是一个用Java编写的简单计算器的示例代码：

```
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class Calculator extends JFrame implements ActionListener {
private JPanel panel;
private JTextField textField;
private JButton button1, button2, button3, button4, button5, button6, button7, button8, button9, button0, buttonAdd, buttonSub, buttonMul, buttonDiv, buttonEqual, buttonClear;
private double number1, number2, result;
private char operator;

public Calculator() {
setTitle("Calculator");
setSize(300, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
panel = new JPanel(new GridLayout(4, 4));
textField = new JTextField();
button1 = new JButton("1");
button2 = new JButton("2");
button3 = new JButton("3");
button4 = new JButton("4");
button5 = new JButton("5");
button6 = new JButton("6");
button7 = new JButton("7");
button8 = new JButton("8");
button9 = new JButton("9");
button0 = new JButton("0");
buttonAdd = new JButton("+");
buttonSub = new JButton("-");
buttonMul = new JButton("*");
buttonDiv = new JButton("/");
buttonEqual = new JButton("=");
buttonClear = new JButton("C");
panel.add(button1);
panel.add(button2);
panel.add(button3);
panel.add(buttonAdd);
panel.add(button4);
panel.add(button5);
panel.add(button6);
panel.add(buttonSub);
panel.add(button7);
panel.add(button8);
panel.add(button9);
panel.add(buttonMul);
panel.add(button0);
panel.add(buttonClear);
panel.add(buttonEqual);
panel.add(buttonDiv);
add(textField, BorderLayout.NORTH);
add(panel, BorderLayout.CENTER);
setVisible(true);
button1.addActionListener(this);
button2.addActionListener(this);
button3.addActionListener(this);
button4.addActionListener(this);
button5.addActionListener(this);
button6.addActionListener(this);
button7.addActionListener(this);
button8.addActionListener(this);
button9.addActionListener(this);
button0.addActionListener(this);
buttonAdd.addActionListener(this);
buttonSub.addActionListener(this);
buttonMul.addActionListener(this);
buttonDiv.addActionListener(this);
buttonEqual.addActionListener(this);
buttonClear.addActionListener(this);
}

public void actionPerformed(ActionEvent event) {
if (event.getSource() == button1) {
textField.setText(textField.getText() + "1");
} else if (event.getSource() == button2) {
textField.setText(textField.getText() + "2");
} else if (event.getSource() == button3) {
textField.setText(textField.getText() + "3");
} else if (event.getSource() == button4) {
textField.setText(textField.getText() + "4");
} else if (event.getSource() == button5) {
textField.setText(textField.getText() + "5");
} else if (event.getSource() == button6) {
textField.setText(textField.getText() + "6");
} else if (event.getSource() == button7) {
textField.setText(textField.getText() + "7");
} else if (event.getSource() == button8) {
textField.setText(textField.getText() + "8");
} else if (event.getSource() == button9) {
textField.setText(textField.getText() + "9");
} else if (event.getSource() == button0) {
textField.setText(textField.getText() + "0");
} else if (event.getSource() == buttonAdd) {
number1 = Double.parseDouble(textField.getText());
operator = '+';
textField.setText("");
} else if (event.getSource() == buttonSub) {
number1 = Double.parseDouble(textField.getText());
operator = '-';
textField.setText("");
} else if (event.getSource() == buttonMul) {
number1 = Double.parseDouble(textField.getText());
operator = '*';
textField.setText("");
} else if (event.getSource() == buttonDiv) {
number1 = Double.parseDouble(textField.getText());
operator = '/';
textField.setText("");
} else if (event.getSource() == buttonEqual) {
number2 = Double.parseDouble(textField.getText());
switch (operator) {
case '+':
result = number1 + number2;
break;
case '-':
result = number1 - number2;
break;
case '*':
result = number1 * number2;
break;
case '/':
result = number1 / number2;
break;
}
textField.setText("" + result);
} else if (event.getSource() == buttonClear) {
textField.setText("");
}
}

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

以上就是用Java编写简单计算器的详细做法，我们只需要了解 Java Swing 类库，接收用户输入的语法，以及 switch 语句等知识点，便可以便捷地建立自己的实用计算器。