「java写计算器的流程图」java写计算器代码
本篇文章给大家谈谈java写计算器的流程图,以及java写计算器代码对应的知识点,希望对各位有所帮助,不要忘了收藏本站喔。
本文目录一览:
- 1、用Java编写一个简单的计算器程序
- 2、怎么用Java写一个计算器。下面有图片
- 3、帮帮忙:Java小计算器代码,及需求分析.流程图.
- 4、怎么用JAVA编程编写一个计算器?
- 5、Java编写计算器的流程图
- 6、Java入门写一个计算器的程序,要求如图
用Java编写一个简单的计算器程序
import java.awt.*;
import java.awt.event.*;
public class CalcAppDemo extends Frame{
private TextField t_result;
private Panel p_main; //主面板
private Panel p_num; //数字面板
private Panel p_oper; //操作符面板
private Panel p_show; //显示面板
private Button b_num[]; //数字按钮
private Button b_oper[]; //操作符面板
public CalcAppDemo(String title){
setTitle(title);
t_result = new TextField("0.0", 21);
p_main = new Panel();
p_num = new Panel();
p_oper = new Panel();
p_show = new Panel();
p_main.setLayout(new BorderLayout());
p_num.setLayout(new GridLayout(4, 3, 1, 1));
p_oper.setLayout(new GridLayout(4, 2, 1, 1));
b_num = new Button[12];
for(int i=0; i9; i++)
{
b_num[i] = new Button(new Integer(i+1).toString());
}
b_num[9] = new Button("0");
b_num[10] = new Button("cls");
b_num[11] = new Button(".");
for(int i=0; i12; i++)
{
p_num.add(b_num[i]);
}
b_oper = new Button[8];
b_oper[0] = new Button("+");
b_oper[1] = new Button("-");
b_oper[2] = new Button("*");
b_oper[3] = new Button("/");
b_oper[4] = new Button("pow");
b_oper[5] = new Button("sqrt");
b_oper[6] = new Button("+/-");
b_oper[7] = new Button("=");
for(int i=0; i8; i++) //
{
p_oper.add(b_oper[i]);
}
t_result.setEditable(false);
p_show.add(t_result, BorderLayout.NORTH);
p_main.add(p_show, BorderLayout.NORTH);
p_main.add(p_num, BorderLayout.WEST);
p_main.add(p_oper, BorderLayout.EAST);
this.add(p_main, BorderLayout.CENTER);
setSize(400, 400);
setResizable(false);
pack();
this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
ButtonListener b1 = new ButtonListener();
for(int i=0; i12; i++)
{
b_num[i].addActionListener(b1);
}
for(int i=0; i8; i++)
{
b_oper[i].addActionListener(b1);
}
}
class ButtonListener implements ActionListener
{
private String lastOp; //存储上一此操作符
private String strVal; //存储数字对应的字符串
private double total; //总数
private double number; //存储新输入的数
private boolean firsttime; //判断是否第一次按下的是操作符按钮
private boolean operatorPressed;//判断是否已经按过操作符按钮
ButtonListener()
{
firsttime = true;
strVal = "";
}
//事件处理器
public void actionPerformed(ActionEvent e)
{
String s = ((Button)e.getSource()).getLabel().trim();
if(Character.isDigit(s.charAt(0)))
{//判断是操作数还是操作符
handleNumber(s);
}
else
{
calculate(s);
}
}
//判断是一元操作符还是二元操作符,并根据操作符类型做计算
void calculate(String op)
{
operatorPressed = true;
if(firsttime! isUnary(op))
{
total = getNumberOnDisplay();
firsttime = false;
}
if(isUnary(op))
{
handleUnaryOp(op);
}
else if(lastOp != null)
{
handleBinaryOp(lastOp);
}
if(! isUnary(op))
{
lastOp = op;
}
}
//判断是否一元操作符
boolean isUnary(String s)
{
return s.equals("=")
||s.equals("cls")||s.equals("sqrt")
||s.equals("+/-")||s.equals(".");
}
//处理一元操作符
void handleUnaryOp(String op)
{
if(op.equals("+/-"))
{//
number = negate(getNumberOnDisplay() + "");
t_result.setText("");
t_result.setText(number + "");
return;
}else if(op.equals("."))
{
handleDecPoint();
return;
}else if(op.equals("sqrt"))
{
number = Math.sqrt(getNumberOnDisplay());
t_result.setText("");
t_result.setText(number + "");
return;
}else if(op.equals("="))
{//
if(lastOp!= null !isUnary(lastOp))
{
handleBinaryOp(lastOp);
}
lastOp = null;
firsttime = true;
return;
}else
{
clear();
}
}
//处理二元运算符
void handleBinaryOp(String op)
{
if(op.equals("+"))
{
total +=number;
}else if(op.equals("-"))
{
total -=number;
}else if(op.equals("*"))
{
total *=number;
}else if(op.equals("/"))
{
try
{
total /=number;
}catch(ArithmeticException ae){}
}else if(op.equals("pow"))
total = Math.pow(total, number);
//t_result.setText("");
lastOp = null;
// strVal = "";
number = 0;
t_result.setText(total + "");
}
//该方法用于处理数字按钮
void handleNumber(String s)
{
if(!operatorPressed)
{
strVal += s;
}else
{
operatorPressed = false;
strVal = s;
}
//
number = new Double(strVal).doubleValue();
t_result.setText("");
t_result.setText(strVal);
}
//该方法用于按下"."按钮
void handleDecPoint()
{
operatorPressed = false;
//
if(strVal.indexOf(".")0)
{
strVal += ".";
}
t_result.setText("");
t_result.setText(strVal);
}
//该方法用于将一个数求反
double negate(String s)
{
operatorPressed = false;
//如果是一个整数,去掉小数点后面的0
if(number == (int)number)
{
s = s.substring(0,s.indexOf("."));
}
//如果无"-"增加在该数的前面
if(s.indexOf("-")0)
{
strVal = "-" + s;
}
else
{
strVal = s.substring(1);
}
return new Double(strVal).doubleValue();
}
//将显示框中的值转换成Double
double getNumberOnDisplay()
{
return new Double(t_result.getText()).doubleValue();
}
//清除屏幕并设置所有的标识
void clear()
{
firsttime = true;
lastOp = null;
strVal = "";
total = 0;
number = 0;
t_result.setText("0");
}
}
public static void main(String[] args) {
CalcAppDemo c = new CalcAppDemo("简单的计算器程序");
c.setVisible(true);
}
}
怎么用Java写一个计算器。下面有图片
//很简单,用脚本引擎类
import java.util.Scanner;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
public class ScriptEngineDemo
{
public static void main(String args[])
{
ScriptEngine sEngine = new ScriptEngineManager().getEngineByName("js");
Scanner scanner = new Scanner(System.in);
String express = "1+2*3";
System.out.println("请输入算是,按回车结束:");
String script = scanner.nextLine();
try {
Number num1 = (Number) sEngine.eval(express);
System.out.println(num1);
Number num2 = (Number) sEngine.eval(script);
System.out.println(num2);
} catch (ScriptException e) {
e.printStackTrace();
}
scanner.close();
}
}
帮帮忙:Java小计算器代码,及需求分析.流程图.
import java.awt.*;//引入包java.awt中所有的类
import java.awt.event.*;//引入包java.awt.event中所有的类.
public class Calculator extends WindowAdapter implements ActionListener//创建Calculator类,
实现ActionListener接口.
{
private double result=0,data1=0,radixPointDepth=1;//定义变量
private boolean radixPointIndicate=false,resultIndicate=false;
private char prec='+';//创建优先默认字符"+"
private Frame f;//创建窗口
private TextField tf;//创建文本框
private Button b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,b17;//创建按钮
private Panel p;//创建/面板容器
static public void main(String args[])//main方法,创建calGUI(图形用户界面),完成初试化
{
//构造器
Calculator de=new Calculator();//创建构造方法
de.go();
}
public void go()
{
f=new Frame("计算器");
p=new Panel();//运算界面p
p.setLayout(new GridLayout(4,4)); // 设置p的布局为GridLayout,四行四列
tf=new TextField(30);
//实例化按钮
b1=new Button("7");
b2=new Button("8");
b3=new Button("9");
b4=new Button("+");
b5=new Button("4");
b6=new Button("5");
b7=new Button("6");
b8=new Button("-");
b9=new Button("1");
b10=new Button("2");
b11=new Button("3");
b12=new Button("*");
b13=new Button("0");
b14=new Button(".");
b15=new Button("=");
b16=new Button("/");
b17=new Button("清零");
f.add(tf,"North"); //把文本区域添加到框架的上方
f.add(p,"Center"); //把面版添加到框架的中间
f.add(b17,"South"); //把按钮(清零)添加到框架的下方
//把按钮添加到面版上
p.add(b1);
p.add(b2);
p.add(b3);
p.add(b4);
p.add(b5);
p.add(b6);
p.add(b7);
p.add(b8);
p.add(b9);
p.add(b10);
p.add(b11);
p.add(b12);
p.add(b13);
p.add(b14);
p.add(b15);
p.add(b16);
//为按钮添加监听
b1.addActionListener(this);
b2.addActionListener(this);
b3.addActionListener(this);
b4.addActionListener(this);
b5.addActionListener(this);
b6.addActionListener(this);
b7.addActionListener(this);
b8.addActionListener(this);
b9.addActionListener(this);
b10.addActionListener(this);
b11.addActionListener(this);
b12.addActionListener(this);
b13.addActionListener(this);
b14.addActionListener(this);
b15.addActionListener(this);
b16.addActionListener(this);
b17.addActionListener(this);
f.addWindowListener(this); //为框架添加监听
f.setSize(300,190);//设置框架的大小
f.setVisible(true);//设置框架为可见
}
//监听程序
public void actionPerformed(ActionEvent e)
{
String s;
s=e.getActionCommand();
//SWITCH开关
switch(s.charAt(0))
{
case '0': case '1': case '2': case '3': case '4': case '5': case '6': case
'7': case '8': case '9'://按了“0-9”,就执行下面
if(resultIndicate)
{
result=0;
data1=0;
prec='+';
}
Integer Int1=new Integer(s);
if(radixPointIndicate)
{
radixPointDepth=radixPointDepth/10;
data1=data1+(Int1.intValue())*radixPointDepth;
}
else
{
data1=data1*10+(Int1.intValue());
}
Double displayNumber=new Double(data1);
tf.setText(displayNumber.toString());
resultIndicate=false;
break;
case '+': case '-':case '*':case '/':case '='://按了“+、-、*、/”,就
执行下面
if(s.charAt(0)!='='resultIndicate)
{
prec=s.charAt(0);
resultIndicate=false;
}
else
{
//用SWITCH开关运算出执行了“+、-、*、/”的结果
switch(prec)
{
case '+':
result=result+data1;
break;
case '-':
result=result-data1;
break;
case '*':
result=result*data1;
break;
case '/':
result=result/data1;
break;
}
}
radixPointIndicate=false;
radixPointDepth=1;
displayNumber=new Double(result);
tf.setText(displayNumber.toString());
//监听是否按了“=”
if(s.charAt(0)!='=')
{
data1=0;
prec=s.charAt(0);
}
else
{
resultIndicate=true;
}
break;
case '.':
radixPointIndicate=true;
break;
}
//监听是否按了为“清零”,是则对各数据清零
if(s.equals("清零"))
{
result=0;
data1=0;
radixPointDepth=1;
tf.setText("");
}
}
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
}
怎么用JAVA编程编写一个计算器?
打开IED:打开自己java编程的软件,采用的是eclipse软件。
建立java工程。
编写类。
编写类的详细步骤
1.类的基本结构:
由于这里用到了界面,所以要进行窗口界面的编程,按钮事件的处理,和计算处理界面;
package MyCaculator;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MyCaculator extends JFrame {
private int add=1,sub=2,mul=3,div=4;
private int op=0;
boolean ifOp;
private String output="0";
private Button[] jba=new Button[]{new Button("7"),new Button("8"),
new Button("9"),new Button("+"),
new Button("4"),new Button("5"),new Button("6"),new Button("-"),
new Button("1"),new Button("2"),new Button("3"),new Button("*"),
new Button("0"),new Button("."),new Button("="),new Button("/")};
private JPanel jpt=new JPanel();
private JPanel jpb=new JPanel();
private JTextField jtf=new JTextField("");
private MyCaculator(){
}
private void operate(String x){
}
public String add(String x){
return output;
}
public String subtract(String x){
return output;
}
public String multiply(String x){
return output;
}
public String divide(String x){
return output;
}
public String Equals(String x){
return output;
}
public void opClean(){
}
class setOperate_Act implements ActionListener{
public void actionPerformed(ActionEvent e) {
}
}
class setLabel_Act implements ActionListener{
public void actionPerformed(ActionEvent e) {
}
}
public static void main(String[] args) {
}
}
2.建立构造方法:
所谓构造方法就是,对自己的主类进行初始化,代码如下:
private MyCaculator(){
jpt.setLayout(new BorderLayout());
jpt.add(jtf);
this.add(jpt,BorderLayout.NORTH);
jpb.setLayout(new GridLayout(4,4));
for(int i=0;ijba.length;i++){
jpb.add(jba[i]);
if(i==3||i==7||i==11||i==15||i==14)
jba[i].addActionListener(new setOperate_Act());
else
jba[i].addActionListener(new setLabel_Act());
}
this.add(jpb,BorderLayout.CENTER);
this.setSize(250, 200);
this.setResizable(false);
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
3.建立数据计算方法
这里的数据计算方法有6个,一个是主方法其他几个是加减乘除的处理方法,代码如下:
private void operate(String x){
double x1=Double.valueOf(x);
double y=Double.valueOf(output);
switch(op){
case 0:output=x;break;
case 1:output=String.valueOf(y+x1);break;
case 2:output =String.valueOf(y-x1);break;
case 3:output =String.valueOf(y*x1);break;
case 4:
if(x1!=0) output=String.valueOf(y/x1);
else output="不能为0";
break;
}
}
public String add(String x){
operate(x);
op=add;
return output;
}
public String subtract(String x){
operate(x);
op=sub;
return output;
}
public String multiply(String x){
operate(x);
op=mul;
return output;
}
public String divide(String x){
operate(x);
op=div;
return output;
}
public String Equals(String x){
operate(x);
op=0;
return output;
}
public void opClean(){
op=0;
output ="0";
}
4.事件处理方法
这里的时间处理方法,没有建立一个整体的方法,二是在为了便于处理的方法,将按钮事件分成两个部分,并采用两个子类来实现,这两个类时内部类要写在主类内部的,代码如下:
class setOperate_Act implements ActionListener{
public void actionPerformed(ActionEvent e) {
if(e.getSource()==jba[3]){
jtf.setText(add(jtf.getText()));
ifOp=true;
}
else if(e.getSource()==jba[7]){
jtf.setText(subtract(jtf.getText()));
ifOp=true;
}
else if(e.getSource()==jba[11]){
jtf.setText(multiply(jtf.getText()));
ifOp=true;
}
else if(e.getSource()==jba[15]){
jtf.setText(divide(jtf.getText()));
ifOp=true;
}
else if(e.getSource()==jba[14]){
jtf.setText(Equals(jtf.getText()));
ifOp=true;
}
}
}
class setLabel_Act implements ActionListener{
public void actionPerformed(ActionEvent e) {
Button tempb=(Button)e.getSource();
if(ifOp){
jtf.setText(tempb.getLabel());
ifOp=false;
}else {
jtf.setText(jtf.getText()+tempb.getLabel());
}
}
}
5.建立main方法:
要想实现我们的代码,我们需在main方法中,实例化我们的对象。
public static void main(String[] args) {
new MyCaculator();
}
Java编写计算器的流程图
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Calculator implements ActionListener
{
String s="",s1;
double d1,d2;
JFrame jf = new JFrame("小计算器by Graduate") ;
JTextField tf = new JTextField();
public void init()//实现计算器界面
{
Container c=jf.getContentPane();
tf.setHorizontalAlignment(JTextField.RIGHT);//文本框
c.add(tf,"North");
JPanel pn3 = new JPanel(new BorderLayout());
c.add(pn3,"Center");
JPanel pn2 = new JPanel();//功能键界面(清除键和关闭键)
pn2.setLayout(new BorderLayout());
JPanel pn1 = new JPanel();//运算界面
pn1.setLayout(new GridLayout(4,4));
pn3.add(pn2,"North");
pn3.add(pn1);
//设置按钮
JButton b = new JButton("CLEAR");
b.setToolTipText("请按清除键!");//设置清零键
b.setForeground(Color.RED);//设置字体颜色
b.setBackground(Color.YELLOW);//设置背景色
b.addActionListener(this);
pn2.add(b,"Center");
b = new JButton("OFF");
b.setToolTipText("请按退出键!");//设置off键,点击退出应用程序b.addActionListener(this);
b.setForeground(Color.RED);//字体颜色
b.setBackground(Color.ORANGE);//背景色
pn2.add(b,"East");
b = new JButton("1");//add butten 1
b.addActionListener(this);
pn1.add(b);
b = new JButton("2");//add butten 2
b.addActionListener(this);
pn1.add(b);
b = new JButton("3");//add butten 3
b.addActionListener(this);
pn1.add(b);
b = new JButton("+");//add butten +
b.setForeground(Color.BLUE);//设置字体颜色
b.addActionListener(this);
pn1.add(b);
b = new JButton("4");//add butten 4
b.addActionListener(this);
pn1.add(b);
b = new JButton("5");//add butten 5
b.addActionListener(this);
pn1.add(b);
b = new JButton("6");//add button 6
b.addActionListener(this);
pn1.add(b);
b = new JButton("-");//add button -
b.setForeground(Color.BLUE);//设置字体颜色
b.addActionListener(this);
pn1.add(b);
b = new JButton("7");//add button 7
b.addActionListener(this);
pn1.add(b);
b = new JButton("8");//add button 8
b.addActionListener(this);
pn1.add(b);
b = new JButton("9");//add button 9
b.addActionListener(this);
pn1.add(b);
b = new JButton("*");//add button *
b.setForeground(Color.BLUE);//设置字体颜色
b.addActionListener(this);
pn1.add(b);
b = new JButton("0");//add button 0
b.addActionListener(this);
pn1.add(b);
b = new JButton(".");//add button .
b.addActionListener(this);
pn1.add(b);
b = new JButton("=");//add button =
b.setForeground(Color.RED);//设置字体颜色
b.addActionListener(this);
pn1.add(b);
b = new JButton("\\");//add button \
b.setForeground(Color.BLUE);//设置字体颜色
b.addActionListener(this);
pn1.add(b);
jf.setSize(300,300);//设置大小
jf.setVisible(true);//设置为可视
}
//处理按钮按下时的动作,进行相应的处理
public void actionPerformed(ActionEvent e)
{
String command = e.getActionCommand();
tf.setText(tf.getText()+command);
if(command.equals("CLEAR")) //清零键 按下时返回初始状态
{
s1=null;
s="";
tf.setText("");//记录输入值的变量清空
}
else if(command.equals("OFF")) System.exit(0);//off键 关闭应用程序
else if(!command.equals("*")!command.equals("\\")
!command.equals("+")!command.equals("-")
!command.equals("="))//判断输入是否为数字
{
if(s1==null)//判断输入是否为第一个
s1 = command;
else s1+=command;
d1 = new Double(s1).doubleValue();//字符串型转换为双精度型,还原输入数字
try
{
if(s.equals("+")) d1 = d1+d2;//加法运算
else if(s.equals("-")) d1 = d2-d1;//减法运算
else if(s.equals("*")) d1 = d1*d2;//乘法运算
else if(s.equals("\\"))d1 = d2/d1;//除法运算
}
catch(Exception ex)
{
tf.setText("Error");//错误显示"Error"
System.out.println(ex.getMessage());
}
}
else if(!command.equals("=")) //判断输入是否为+ - * \
{
s = command;
s1 = null;
d2 = d1;
}
else//输入=时,显示运算结果
{
tf.setText(tf.getText()+d1);
}
}
public static void main(String [] args)
{
new Calculator().init();
}
}
Java入门写一个计算器的程序,要求如图
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import java.util.LinkedList; //工具包
import java.text.NumberFormat; //文本包
/**
* java swing计算器
* @author young
*
*/
public class Calculator extends Frame implements ActionListener // 计算器类
{
JTextField result;
NumberButton numberButton[];
OperatorButton operatorButton[];
Button radixpoint, positiveminus, backspace, reciprocal, equal, clear; // 声明成员变量
// 小数点按钮,正负号按钮,退格按钮,求倒数按钮,等号按钮,清零按钮
Panel panel;
String operator[] = { "+", "-", "*", "/" };
LinkedList linklist;
boolean pressequal = false;
public Calculator() // 构造方法
{
super("计算器");
linklist = new LinkedList();
numberButton = new NumberButton[10];
for (int i = 0; i = 9; i++) {
numberButton[i] = new NumberButton(i);
numberButton[i].addActionListener(this);
}
operatorButton = new OperatorButton[4];
for (int i = 0; i 4; i++) {
operatorButton[i] = new OperatorButton(operator[i]);
operatorButton[i].addActionListener(this);
}
radixpoint = new Button(".");
positiveminus = new Button("+/-");
backspace = new Button("CE");
reciprocal = new Button("1/x");
equal = new Button("=");
clear = new Button("C");
radixpoint.setForeground(Color.red);
positiveminus.setForeground(Color.red);
backspace.setForeground(Color.red);
reciprocal.setForeground(Color.red);
equal.setForeground(Color.red);
clear.setForeground(Color.red);
radixpoint.addActionListener(this);
positiveminus.addActionListener(this);
backspace.addActionListener(this);
reciprocal.addActionListener(this);
equal.addActionListener(this);
clear.addActionListener(this);
result = new JTextField(10);
result.setHorizontalAlignment(JTextField.RIGHT);
result.setForeground(Color.black);
result.setBackground(Color.white);
result.setFont(new Font("TimesRoman", Font.PLAIN, 14));
result.setBorder(new SoftBevelBorder(BevelBorder.LOWERED));
result.setEditable(false);
panel = new Panel();
panel.setLayout(new GridLayout(4, 5));
panel.add(numberButton[1]);
panel.add(numberButton[2]);
panel.add(numberButton[3]);
panel.add(backspace);
panel.add(clear);
panel.add(numberButton[4]);
panel.add(numberButton[5]);
panel.add(numberButton[6]);
panel.add(operatorButton[0]);
panel.add(operatorButton[2]);
panel.add(numberButton[7]);
panel.add(numberButton[8]);
panel.add(numberButton[9]);
panel.add(operatorButton[1]);
panel.add(operatorButton[3]);
panel.add(numberButton[0]);
panel.add(positiveminus);
panel.add(reciprocal);
panel.add(radixpoint);
panel.add(equal);
add(result, "North");
add(panel, "Center");
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
setSize(270, 200);
setLocation(300, 230);
setVisible(true);
}
public void actionPerformed(ActionEvent e) // 按钮的单击事件处理方法
{
if (e.getSource() instanceof NumberButton) // 数字按钮
{
NumberButton b = (NumberButton) e.getSource();
if (linklist.size() == 0) {
int number = b.getNumber();
linklist.add("" + number);
result.setText("" + number);
pressequal = false;
}
else if (linklist.size() == 1 pressequal == false) {
int number = b.getNumber();
String num = (String) linklist.getFirst();
String s = num.concat("" + number);
linklist.set(0, s);
result.setText(s);
} else if (linklist.size() == 1 pressequal == true) {
int number = b.getNumber();
linklist.removeFirst();
linklist.add("" + number);
pressequal = false;
result.setText("" + number);
} else if (linklist.size() == 2) {
int number = b.getNumber();
linklist.add("" + number);
result.setText("" + number);
} else if (linklist.size() == 3) {
int number = b.getNumber();
String num = (String) linklist.getLast();
String s = num.concat("" + number);
linklist.set(2, s);
result.setText(s);
}
} else if (e.getSource() instanceof OperatorButton) // 操作按钮
{
OperatorButton b = (OperatorButton) e.getSource();
if (linklist.size() == 1) {
String fuhao = b.getOperator();
linklist.add(fuhao);
} else if (linklist.size() == 2) {
String fuhao = b.getOperator();
linklist.set(1, fuhao);
} else if (linklist.size() == 3) {
String fuhao = b.getOperator();
String number1 = (String) linklist.getFirst();
String number2 = (String) linklist.getLast();
String operator = (String) linklist.get(1);
try {
double n1 = Double.parseDouble(number1);
double n2 = Double.parseDouble(number2);
double n = 0;
if (operator.equals("+")) {
n = n1 + n2;
} else if (operator.equals("-")) {
n = n1 - n2;
} else if (operator.equals("*")) {
n = n1 * n2;
} else if (operator.equals("/")) {
n = n1 / n2;
}
linklist.clear();
linklist.add("" + n);
linklist.add(fuhao);
result.setText("" + n);
} catch (Exception ee) {
}
}
} else if (e.getSource() == equal) // 等号按钮
{
pressequal = true;
if (linklist.size() == 1 || linklist.size() == 2) {
String num = (String) linklist.getFirst();
result.setText("" + num);
} else if (linklist.size() == 3) {
String number1 = (String) linklist.getFirst();
String number2 = (String) linklist.getLast();
String operator = (String) linklist.get(1);
try {
double n1 = Double.parseDouble(number1);
double n2 = Double.parseDouble(number2);
double n = 0;
if (operator.equals("+")) {
n = n1 + n2;
} else if (operator.equals("-")) {
n = n1 - n2;
} else if (operator.equals("*")) {
n = n1 * n2;
} else if (operator.equals("/")) {
n = n1 / n2;
}
result.setText("" + n);
linklist.set(0, "" + n);
linklist.removeLast();
linklist.removeLast();
} catch (Exception ee) {
}
}
} else if (e.getSource() == radixpoint) // 小数点按钮
{
if (linklist.size() == 0) {
pressequal = false;
} else if (linklist.size() == 1) {
String dot = radixpoint.getLabel();
String num = (String) linklist.getFirst();
String s = null;
if (num.indexOf(dot) == -1) {
s = num.concat(dot);
linklist.set(0, s);
} else {
s = num;
}
linklist.set(0, s);
result.setText(s);
}
else if (linklist.size() == 3) {
String dot = radixpoint.getLabel();
String num = (String) linklist.getLast();
String s = null;
if (num.indexOf(dot) == -1) {
s = num.concat(dot);
linklist.set(2, s);
} else {
s = num;
}
result.setText(s);
}
} else if (e.getSource() == backspace) // 退格按钮
{
if (linklist.size() == 1) {
String num = (String) linklist.getFirst();
if (num.length() = 1) {
num = num.substring(0, num.length() - 1);
linklist.set(0, num);
result.setText(num);
} else {
linklist.removeLast();
result.setText("0");
}
} else if (linklist.size() == 3) {
String num = (String) linklist.getLast();
if (num.length() = 1) {
num = num.substring(0, num.length() - 1);
linklist.set(2, num);
result.setText(num);
} else {
linklist.removeLast();
result.setText("0");
}
}
} else if (e.getSource() == positiveminus) // 正负号按钮
{
if (linklist.size() == 1) {
String number1 = (String) linklist.getFirst();
try {
double d = Double.parseDouble(number1);
d = -1 * d;
String str = String.valueOf(d);
linklist.set(0, str);
result.setText(str);
} catch (Exception ee) {
}
} else if (linklist.size() == 3) {
String number2 = (String) linklist.getLast();
try {
double d = Double.parseDouble(number2);
d = -1 * d;
String str = String.valueOf(d);
linklist.set(2, str);
result.setText(str);
} catch (Exception ee) {
}
}
} else if (e.getSource() == reciprocal) // 求倒数按钮
{
if (linklist.size() == 1 || linklist.size() == 2) {
String number1 = (String) linklist.getFirst();
try {
double d = Double.parseDouble(number1);
d = 1.0 / d;
String str = String.valueOf(d);
linklist.set(0, str);
result.setText(str);
} catch (Exception ee) {
}
} else if (linklist.size() == 3) {
String number2 = (String) linklist.getLast();
try {
double d = Double.parseDouble(number2);
d = 1.0 / d;
String str = String.valueOf(d);
linklist.set(0, str);
result.setText(str);
} catch (Exception ee) {
}
}
} else if (e.getSource() == clear) // 清零按钮
{
pressequal = false;
result.setText("0");
linklist.clear();
}
}
public static void main(String args[]) {
new Calculator();
}
}
class NumberButton extends Button // 数字按钮类
{
int number;
public NumberButton(int number) // 构造方法
{
super("" + number);
this.number = number;
setForeground(Color.blue);
}
public int getNumber() {
return number;
}
}
class OperatorButton extends Button // 运算符号按钮类
{
String operator;
public OperatorButton(String operator) // 构造方法
{
super(operator);
this.operator = operator;
setForeground(Color.red);
}
public String getOperator() {
return operator;
}
}
这就是代码了。
java写计算器的流程图的介绍就聊到这里吧,感谢你花时间阅读本站内容,更多关于java写计算器代码、java写计算器的流程图的信息别忘了在本站进行查找喔。
发布于:2022-11-26,除非注明,否则均为
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