这篇“如何使用java代码实现计算器”文章的知识点大部分人都不太理解，所以小编给大家总结了以下内容，内容详细，步骤清晰，具有一定的借鉴价值，希望大家阅读完这篇文章能有所收获，下面我们一起来看看这篇“如何使用java代码实现计算器”文章吧。
运行环境：win10 Eclipse IDE for Java Developers - 2020-06
下面是计算器的视图：
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
/*
* 计算器
*/
public class CaculatorTest implements ActionListener {
// 初始框架搭建
JFrame frame = new JFrame("计算器");
JTextField area = new JTextField("0");
JPanel panel1 = new JPanel();
JPanel panel2 = new JPanel();
JButton[] buttons = new JButton[20];
String[] buttonsText = { "sqrt", "退格", "C", "/", "7", "8", "9", "*", "4", "5", "6", "-", "1", "2", "3", "+", "0",
".", "+/-", "=" };
boolean point = false; // 用于判断是否输入多位小数点
boolean key = true; // 做完运算("=")后继续输入数字
String sign = " "; // 用于判断和记录运算符号
double temp = 0; // 多次连续运算时，值的寄存处
public CaculatorTest() {
initMenu();
initText();
initExtend();
initFrame();
initBorderLayout();
}
// 初始化菜单
private void initMenu() {
JMenuBar mb = new JMenuBar();
JMenu m1 = new JMenu("选项");
JMenu m2 = new JMenu("编辑");
JMenu m3 = new JMenu("帮助");
JMenuItem m11 = new JMenuItem("普通型计算器");
JMenuItem m12 = new JMenuItem("科学型计算器");
m1.add(m11);
m1.add(m12);
m11.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
boolean flag = false;
panel2.setVisible(flag);
frame.pack();
}
});
m12.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
boolean flag = true;
panel2.setVisible(flag);
frame.pack();
}
});
mb.add(m1);
mb.add(m2);
mb.add(m3);
frame.setJMenuBar(mb);
}
// 初始化输出文本域
private void initText() {
area.setFont(new Font("TimesRoman", Font.PLAIN, 20));
area.setSize(400, 100);
area.setHorizontalAlignment(JTextField.RIGHT); // 向右显示
}
// 初始化拓展功能
private void initExtend() {
panel2.setLayout(new GridLayout(1,4,1,1));
JButton b1 = new JButton("sin");
JButton b2 = new JButton("cos");
JButton b3 = new JButton("exp");
JButton b4 = new JButton("ln");
b1.setFont(new Font("TimesRoman", Font.PLAIN, 20));
b2.setFont(new Font("TimesRoman", Font.PLAIN, 20));
b3.setFont(new Font("TimesRoman", Font.PLAIN, 20));
b4.setFont(new Font("TimesRoman", Font.PLAIN, 20));
b1.setSize(100, 100);
b1.addActionListener(this);
b2.setSize(100, 100);
b2.addActionListener(this);
b3.setSize(100, 100);
b3.addActionListener(this);
b4.setSize(100, 100);
b4.addActionListener(this);
panel2.add(b1);
panel2.add(b2);
panel2.add(b3);
panel2.add(b4);
}
// 初始化计算器基本界面
private void initFrame() {
panel1.setLayout(new GridLayout(5, 4, 1, 1));
for (int i = 0; i < buttonsText.length; i++) {
JButton button = new JButton(buttonsText[i]);
button.setSize(100, 100);
button.setFont(new Font("TimesRoman", Font.PLAIN, 20));
button.addActionListener(this);
panel1.add(button);
}
}
// 初始化计算器总基本界面
private void initBorderLayout() {
frame.setLayout(new BorderLayout());
frame.add(panel1, BorderLayout.SOUTH); // 插入组件
frame.add(area, BorderLayout.NORTH);
frame.add(panel2, BorderLayout.CENTER);
frame.setLocation(700, 400);
frame.setSize(400, 700);
frame.setVisible(true); // 设置可见
panel2.setVisible(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 可以关闭
frame.pack();
}
public static void main(String[] args) {
new CaculatorTest();
}
@Override
// 事件监听
public void actionPerformed(ActionEvent e) {
String str = e.getActionCommand();
String str2 = area.getText();
if (str == "0" || str == "1" || str == "2" || str == "3" || str == "4" || str == "5" || str == "6" || str == "7"
|| str == "8" || str == "9") {
if (key == false) {
area.setText(str2 + str);
} else {
area.setText(str);
key = false;
}
} else if (str == "C") {
area.setText("0");
sign = " ";
key = true;
} else if (str == ".") {
if (point == false) {
area.setText(str2 + str);
point = true;
} else {
area.setText("double poits!press C to update!");
point = false;
}
} else if (str == "+/-") {
double num = Double.valueOf(str2);
num = -num;
area.setText(String.valueOf(num));
} else if (str == "退格") {
if (str2.length() == 0) {
area.setText("can't be deleted!please press C!");
} else {
str2 = str2.substring(0, str2.length() - 1);
area.setText(str2);
}
} else if (str == "sqrt") {
area.setText("");
sign = "s";
} else if (str == "sin") {
area.setText("");
sign = "sin";
} else if (str == "cos") {
area.setText("");
sign = "cos";
} else if (str == "exp") {
area.setText("");
sign = "exp";
} else if (str == "ln") {
area.setText("");
sign = "ln";
} else {
if (str == "+") {
if (sign == " ") {
sign = "+";
temp = Double.valueOf(str2);
area.setText("");
} else if (sign == "-") {
if (str2.length() == 0) {
sign = "+";
} else {
temp = temp - Double.valueOf(str2);
sign = "+";
area.setText("");
key = true;
}
} else if (sign == "+") {
if (str2.length() == 0) {
sign = "+";
} else {
temp = temp + Double.valueOf(str2);
sign = "+";
area.setText("");
key = true;
}
} else if (sign == "*") {
if (str2.length() == 0) {
sign = "+";
} else {
temp = temp * Double.valueOf(str2);
sign = "+";
area.setText("");
key = true;
}
} else if (sign == "/") {
if (str2.length() == 0) {
sign = "+";
} else if (Double.valueOf(str2) == 0) {
area.setText("除数不能为0哦！按 C");
} else {
temp = temp / Double.valueOf(str2);
area.setText("");
sign = "+";
key = true;
}
} else if (sign == "s") {
if (str2.length() == 0) {
sign = "+";
} else {
temp = Math.sqrt(Double.valueOf(str2));
area.setText("");
sign = "+";
}
} else if (sign == "sin") {
if (str2.length() == 0) {
sign = "+";
} else {
temp = Math.sin(Double.valueOf(str2));
area.setText("");
sign = "+";
}
} else if (sign == "cos") {
if (str2.length() == 0) {
sign = "+";
} else {
temp = Math.cos(Double.valueOf(str2));
area.setText("");
sign = "+";
}
} else if (sign == "exp") {
if (str2.length() == 0) {
sign = "+";
} else {
temp = Math.exp(Double.valueOf(str2));
area.setText("");
sign = "+";
}
} else if (sign == "ln") {
if (str2.length() == 0) {
sign = "+";
} else {
temp = Math.log(Double.valueOf(str2));
area.setText("");
sign = "+";
}
}
} else if (str == "-") {
if (sign == " ") {
sign = "-";
temp = Double.valueOf(str2);
area.setText("");
} else if (sign == "-") {
if (str2.length() == 0) {
sign = "-";
} else {
temp = temp - Double.valueOf(str2);
sign = "-";
area.setText("");
key = true;
}
} else if (sign == "+") {
if (str2.length() == 0) {
sign = "-";
} else {
temp = temp + Double.valueOf(str2);
sign = "-";
area.setText("");
key = true;
}
} else if (sign == "*") {
if (str2.length() == 0) {
sign = "-";
} else {
temp = temp * Double.valueOf(str2);
sign = "-";
area.setText("");
key = true;
}
} else if (sign == "/") {
if (str2.length() == 0) {
sign = "-";
} else if (Double.valueOf(str2) == 0) {
area.setText("除数不能为0哦！按 C");
} else {
temp = temp / Double.valueOf(str2);
area.setText("");
sign = "-";
key = true;
}
} else if (sign == "s") {
if (str2.length() == 0) {
sign = "-";
} else {
temp = Math.sqrt(Double.valueOf(str2));
area.setText("");
sign = "-";
}
} else if (sign == "sin") {
if (str2.length() == 0) {
sign = "-";
} else {
temp = Math.sin(Double.valueOf(str2));
area.setText("");
sign = "-";
}
} else if (sign == "cos") {
if (str2.length() == 0) {
sign = "-";
} else {
temp = Math.cos(Double.valueOf(str2));
area.setText("");
sign = "-";
}
} else if (sign == "exp") {
if (str2.length() == 0) {
sign = "-";
} else {
temp = Math.exp(Double.valueOf(str2));
area.setText("");
sign = "-";
}
} else if (sign == "ln") {
if (str2.length() == 0) {
sign = "-";
} else {
temp = Math.log(Double.valueOf(str2));
area.setText("");
sign = "-";
}
}
} else if (str == "*") {
if (sign == " ") {
sign = "*";
temp = Double.valueOf(str2);
area.setText("");
} else if (sign == "-") {
if (str2.length() == 0) {
sign = "*";
} else {
temp = temp - Double.valueOf(str2);
sign = "*";
area.setText("");
key = true;
}
} else if (sign == "+") {
if (str2.length() == 0) {
sign = "*";
} else {
temp = temp + Double.valueOf(str2);
sign = "*";
area.setText("");
key = true;
}
} else if (sign == "*") {
if (str2.length() == 0) {
sign = "*";
} else {
temp = temp * Double.valueOf(str2);
sign = "*";
area.setText("");
key = true;
}
} else if (sign == "/") {
if (str2.length() == 0) {
sign = "*";
} else if (Double.valueOf(str2) == 0) {
area.setText("除数不能为0哦！按 C");
} else {
temp = temp / Double.valueOf(str2);
area.setText("");
sign = "*";
key = true;
}
} else if (sign == "s") {
if (str2.length() == 0) {
sign = "*";
} else {
temp = Math.sqrt(Double.valueOf(str2));
area.setText("");
sign = "*";
}
} else if (sign == "sin") {
if (str2.length() == 0) {
sign = "*";
} else {
temp = Math.sin(Double.valueOf(str2));
area.setText("");
sign = "*";
}
} else if (sign == "cos") {
if (str2.length() == 0) {
sign = "*";
} else {
temp = Math.cos(Double.valueOf(str2));
area.setText("");
sign = "*";
}
} else if (sign == "exp") {
if (str2.length() == 0) {
sign = "*";
} else {
temp = Math.exp(Double.valueOf(str2));
area.setText("");
sign = "*";
}
} else if (sign == "ln") {
if (str2.length() == 0) {
sign = "*";
} else {
temp = Math.log(Double.valueOf(str2));
area.setText("");
sign = "*";
}
}
} else if (str == "/") {
if (sign == " ") {
sign = "/";
temp = Double.valueOf(str2);
area.setText("");
} else if (sign == "-") {
if (str2.length() == 0) {
sign = "/";
} else {
temp = temp - Double.valueOf(str2);
sign = "/";
area.setText("");
key = true;
}
} else if (sign == "+") {
if (str2.length() == 0) {
sign = "/";
} else {
temp = temp + Double.valueOf(str2);
sign = "/";
area.setText("");
key = true;
}
} else if (sign == "*") {
if (str2.length() == 0) {
sign = "/";
} else {
temp = temp * Double.valueOf(str2);
sign = "/";
area.setText("");
key = true;
}
} else if (sign == "/") {
if (str2.length() == 0) {
sign = "/";
} else if (Double.valueOf(str2) == 0) {
area.setText("除数不能为0哦！按 C");
} else {
temp = temp / Double.valueOf(str2);
area.setText("");
sign = "/";
key = true;
}
} else if (sign == "s") {
if (str2.length() == 0) {
sign = "/";
} else {
temp = Math.sqrt(Double.valueOf(str2));
area.setText("");
sign = "/";
}
} else if (sign == "sin") {
if (str2.length() == 0) {
sign = "/";
} else {
temp = Math.sin(Double.valueOf(str2));
area.setText("");
sign = "/";
}
} else if (sign == "cos") {
if (str2.length() == 0) {
sign = "/";
} else {
temp = Math.cos(Double.valueOf(str2));
area.setText("");
sign = "/";
}
} else if (sign == "exp") {
if (str2.length() == 0) {
sign = "/";
} else {
temp = Math.exp(Double.valueOf(str2));
area.setText("");
sign = "/";
}
} else if (sign == "ln") {
if (str2.length() == 0) {
sign = "/";
} else {
temp = Math.log(Double.valueOf(str2));
area.setText("");
sign = "/";
}
}
} else if (str == "=") {
if (sign == "+") {
if (str2.length() == 0) {
area.setText(String.valueOf(temp));
sign = " ";
} else {
temp = temp + Double.valueOf(str2);
area.setText(String.valueOf(temp));
sign = " ";
}
} else if (sign == "-") {
if (str2.length() == 0) {
area.setText(String.valueOf(temp));
sign = " ";
} else {
temp = temp - Double.valueOf(str2);
area.setText(String.valueOf(temp));
sign = " ";
}
} else if (sign == "*") {
if (str2.length() == 0) {
area.setText(String.valueOf(temp));
sign = " ";
} else {
temp = temp * Double.valueOf(str2);
area.setText(String.valueOf(temp));
sign = " ";
}
} else if (sign == "/") {
if (Double.valueOf(str2) == 0) {
area.setText("除数不能为0哦！按C");
sign = " ";
} else {
temp = temp / Double.valueOf(str2);
area.setText(String.valueOf(temp));
sign = " ";
}
} else if (sign == " ") {
if (str2.length() == 0) {
area.setText(String.valueOf(temp));
} else {
temp = Double.valueOf(str2);
area.setText(String.valueOf(temp));
}
} else if (sign == "s") {
temp = Math.sqrt(Double.valueOf(str2));
area.setText(String.valueOf(temp));
sign = " ";
} else if (sign == "sin") {
temp = Math.sin(Double.valueOf(str2));
area.setText(String.valueOf(temp));
sign = " ";
} else if (sign == "cos") {
temp = Math.cos(Double.valueOf(str2));
area.setText(String.valueOf(temp));
sign = " ";
} else if (sign == "exp") {
temp = Math.exp(Double.valueOf(str2));
area.setText(String.valueOf(temp));
sign = " ";
} else if (sign == "ln") {
temp = Math.log(Double.valueOf(str2));
area.setText(String.valueOf(temp));
sign = " ";
}
key = true;
}
}
}
}以上就是关于“如何使用java代码实现计算器”这篇文章的内容，相信大家都有了一定的了解，希望小编分享的内容对大家有帮助，若想了解更多相关的知识内容，请关注亿速云行业资讯频道。
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