用java编写计算器用了什么技术(能够用Java编写一个计算器是什么水平了)

编程之家2023-10-1289次浏览

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JAVA 编写计算器要代码最简单的

学java的时候自己编的，很简单，能够连续输入计算式后进行计算

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.FlowLayout;

import java.awt.Font;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.text.NumberFormat;

import java.util.ArrayList;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.JTextField;

/**简易计算器，能够进行简单的计算

*@see 2008.12.9

public class CalculatorA

implements ActionListener{

private JFrame frame;

private JTextField field;

private JButton[] allButtons;

private JButton clearButton;

// private JButton backButton;

String result="";//保存结果

StringBuilder sb= new StringBuilder();//保存要进行的计算式

int x= 0;//用来判断上一次的事件类型

String str="123+456-789*0.=/";

ArrayList<String> arrayList= new ArrayList<String>();//保存计算式，通过方法进行运算

public CalculatorA(){

frame= new JFrame("我的计算器v1.1");

frame.setLocation(300,300);

field= new JTextField(25);

allButtons= new JButton[16];

for(int i=0;i<allButtons.length;i++){

allButtons[i]= new JButton(str.substring(i,i+1));

}

clearButton= new JButton("CLEAR");

// backButton= new JButton("<——");

init();

setFondAndColor();

addEventHander();

}

public void init(){

frame.setLayout(new BorderLayout());

JPanel northPanel= new JPanel();

JPanel centerPanel= new JPanel();

JPanel southPanel= new JPanel();

northPanel.setLayout(new FlowLayout());

centerPanel.setLayout(new GridLayout(4,4));

southPanel.setLayout(new FlowLayout());

northPanel.add(field);

for(int i=0;i<allButtons.length;i++){

centerPanel.add(allButtons[i]);

}

southPanel.add(clearButton);

//southPanel.add(backButton);

frame.add(northPanel,BorderLayout.NORTH);

frame.add(centerPanel,BorderLayout.CENTER);

frame.add(southPanel,BorderLayout.SOUTH);

}

//设置输入字体

public void setFondAndColor(){

field.setFont(new Font("宋体",Font.BOLD,24));

field.setBackground(new Color(100,200,200));

field.setForeground(Color.RED);

//设置字体从右起始

field.setHorizontalAlignment(JTextField.RIGHT);

}

public void showMi(){

frame.pack();

frame.setResizable(false);

frame.setVisible(true);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

public void addEventHander(){

for(int i=0;i<allButtons.length;i++){

allButtons[i].addActionListener(this);

}

clearButton.addActionListener(this);

// backButton.addActionListener(this);

}

@Override

public void actionPerformed(ActionEvent e){

String str= e.getActionCommand();//取得当前事件返回的值

if("0123456789.".indexOf(str)!=-1){

if(x== 0){//当x为0时表示还没有进行输入

result=str;

sb.append(str);

field.setText(str);

x= 1;

}

else if(x== 1){

result= result+str;

sb.append(str);

field.setText(result);

x= 1;

}

else if(x== 2){

sb.delete(0,sb.length());

result= result+str;

sb.append(str);

field.setText(result);

x= 1;

}

else if(x== 3){

result= str;

sb.delete(0,sb.length());

arrayList.clear();

field.setText(str);

sb.append(str);

field.setText(str);

x= 1;

}

else if(x== 4){

result="";

sb.delete(0,sb.length());

arrayList.clear();

result= str;

sb.append(str);

field.setText(str);

x= 1;

}

else{

result= result+str;

sb.append(str);

field.setText(result);

x= 1;

}

else if("+*-/".indexOf(str)!=-1){

if(x== 0){

field.setText("");

x= 2;

}

else if(x== 1){

result= result+ str;

arrayList.add(sb.toString());

arrayList.add(str);

sb.append(str);

field.setText(result);

x= 2;

}

else if(x== 2){

x= 2;

}

else if(x== 3){

field.setText(result+str);

arrayList.add(result);

arrayList.add(str);

result= result+str;

x= 2;

}

else if(x== 4){

result="";

sb.delete(0,sb.length());

arrayList.clear();

x= 2;

}

else{

field.setText(result+str);

arrayList.add(result);

arrayList.add(str);

result= result+str;

x= 2;

}

else if("=".equals(str)){

if(x== 0){

field.setText("0");

arrayList.clear();

result="0";

x= 3;

}

else if(x== 1){

try{

arrayList.add(sb.toString());

arrayList= getResult(arrayList);

result= arrayList.get(0);

field.setText(result);

arrayList.clear();

x= 3;

}catch(Exception e1){

field.setText("数据格式异常");

x= 0;

}

else if(x== 2){

field.setText("数据格式错误.....");

arrayList.clear();

x= 0;

}

else if(x== 3){

field.setText(result);

x= 3;

}

else if(x== 4){

result="";

sb.delete(0,sb.length());

arrayList.clear();

x= 3;

}

else{

try{

arrayList.add(sb.toString());

arrayList= getResult(arrayList);

result= arrayList.get(0);

field.setText(result);

arrayList.clear();

x= 3;

}catch(Exception e1){

field.setText("数据格式异常");

x= 0;

}

else if("CLEAR".equals(str)){

arrayList.clear();

field.setText("0");

arrayList.add("0");

x= 4;

}

else{

if(result.length()>1){

result= result.substring(0,result.length()-1);

if(sb.length()>0){

sb.delete(sb.length()-1,sb.length());

}

else{

sb.delete(0,1);

}

field.setText(result);

x= 5;

}

else{

result="";

sb.delete(0,sb.length());

arrayList.clear();

field.setText("0");

x= 0;

}

public static ArrayList<String> getResult(ArrayList<String> list){

String res= null;

String[] s={"/","*","-","+"};

int i=0;

if(list.size()>1){

for(;i<s.length;){

if(s[i].equals("/")){

for(int j=0;j<list.size();j++){

if(list.get(j).equals(s[i])){

res= Double.toString(Double.parseDouble(list.get(j-1))/Double.parseDouble(list.get(j+1)));

//本地的数据格式

NumberFormat nf= NumberFormat.getInstance();

res= nf.format(Double.parseDouble(res));

res= getChange(res);

list.set(j-1,res);

list.remove(j);

getResult(list);

}

i++;

}

else if(s[i].equals("*")){

for(int j=0;j<list.size();j++){

if(list.get(j).equals(s[i])){

res= Double.toString(Double.parseDouble(list.get(j-1))*Double.parseDouble(list.get(j+1)));

NumberFormat nf= NumberFormat.getInstance();

res= nf.format(Double.parseDouble(res));

res= getChange(res);

list.set(j-1,res);

list.remove(j);

getResult(list);

}

i++;

}

else if(s[i].equals("-")){

for(int j=0;j<list.size();j++){

if(list.get(j).equals(s[i])){

res= Double.toString(Double.parseDouble(list.get(j-1))-Double.parseDouble(list.get(j+1)));

NumberFormat nf= NumberFormat.getNumberInstance();

res= nf.format(Double.parseDouble(res));

res= getChange(res);

list.set(j-1,res);

list.remove(j);

getResult(list);

}

i++;

}

else{

for(int j=0;j<list.size();j++){

if(list.get(j).equals(s[i])){

res= Double.toString(Double.parseDouble(list.get(j-1))+Double.parseDouble(list.get(j+1)));

NumberFormat nf= NumberFormat.getInstance();

res= nf.format(Double.parseDouble(res));

res= getChange(res);

list.set(j-1,res);

list.remove(j);

getResult(list);

}

i++;

}

return list;

}

//对数字字符串进行排除不必要符号

public static String getChange(String res){

String s_temp="";

char[] c= new char[res.length()];

for(int k=0;k<c.length;k++){

c[k]= res.charAt(k);

}

for(int k=0;k<c.length;k++){

if((c[k]>='0'&& c[k]<='9')|| c[k]=='.'){

s_temp+= c[k];

}

return s_temp;

}

public static void main(String[] args){

new CalculatorA().showMi();

}

求"用JAVA编写的计算器程序代码"

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

import javax.swing.event.*;

public class jsq

{

public static void main(String[] str)

{

jisuanqi jsq=new jisuanqi();

jsq.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

jsq.setVisible(true);jsq.setSize(300,300);

}

class jisuanqi extends JFrame implements ActionListener

{

double a=0,b=0,c=0,fuhao=5;

Boolean has=false;

Container A;

JTextField tf1;

JButton bt1,bt2,bt3,bt4,bt5,bt6,bt7,bt8,bt9,bt0,bt_dian;

JButton bt_jia,bt_jian,bt_cheng,bt_chu,bt_fuhao;

JButton bt_clear,bt_jisuan;

public jisuanqi()

{

setTitle("简单计算器");

A=getContentPane();

GridBagLayout f=new GridBagLayout();

A.setLayout(f);

GridBagConstraints g=new GridBagConstraints();

g.fill=GridBagConstraints.BOTH;

g.gridwidth=1;

g.gridheight=1;

//面板的实例化

//显示框的实例化

tf1=new JTextField(10);tf1.setEditable(false);

//数字键的实例化

bt1=new JButton("1");bt2=new JButton("2");bt3=new JButton("3");

bt4=new JButton("4");bt5=new JButton("5");bt6=new JButton("6");

bt7=new JButton("7");bt8=new JButton("8");bt9=new JButton("9");

bt0=new JButton("0");bt_dian=new JButton(".");bt_fuhao=new JButton("+/-");

//计算符号的实例化

bt_jia=new JButton("+");bt_jian=new JButton("-");

bt_cheng=new JButton("*");bt_chu=new JButton("/");

//清空和计算按钮的实例化

bt_clear=new JButton("clear");bt_jisuan=new JButton("=");

//布局

g.gridx=1;g.gridy=0;A.add(tf1,g);

g.gridx=0;g.gridy=1;A.add(bt_clear,g);

g.gridx=3;g.gridy=1;A.add(bt_jisuan,g);

g.gridx=0;g.gridy=2;A.add(bt7,g);

g.gridx=1;g.gridy=2;A.add(bt8,g);

g.gridx=2;g.gridy=2;A.add(bt9,g);

g.gridx=3;g.gridy=2;A.add(bt_jia,g);

g.gridx=0;g.gridy=3;A.add(bt4,g);

g.gridx=1;g.gridy=3;A.add(bt5,g);

g.gridx=2;g.gridy=3;A.add(bt6,g);

g.gridx=3;g.gridy=3;A.add(bt_jian,g);

g.gridx=0;g.gridy=4;A.add(bt1,g);

g.gridx=1;g.gridy=4;A.add(bt2,g);

g.gridx=2;g.gridy=4;A.add(bt3,g);

g.gridx=3;g.gridy=4;A.add(bt_cheng,g);

g.gridx=0;g.gridy=5;A.add(bt0,g);

g.gridx=1;g.gridy=5;A.add(bt_fuhao,g);

g.gridx=2;g.gridy=5;A.add(bt_dian,g);

g.gridx=3;g.gridy=5;A.add(bt_chu,g);

//添加监听

bt1.addActionListener(this);

bt2.addActionListener(this);

bt3.addActionListener(this);

bt4.addActionListener(this);

bt5.addActionListener(this);

bt6.addActionListener(this);

bt7.addActionListener(this);

bt8.addActionListener(this);

bt9.addActionListener(this);

bt0.addActionListener(this);

//清除、小数点、符号添加监听

bt_clear.addActionListener(this);

bt_dian.addActionListener(this);

bt_fuhao.addActionListener(this);

//符号添加监听

bt_jia.addActionListener(this);

bt_jian.addActionListener(this);

bt_cheng.addActionListener(this);

bt_chu.addActionListener(this);

//计算符号添加监听

bt_jisuan.addActionListener(this);

}

public void actionPerformed(ActionEvent e)

{

//数字键

if(e.getSource()==bt1)

{tf1.setText(tf1.getText()+"1");}

else if(e.getSource()==bt2)

{