求简单JAVA程序代码，能操作的，简单的计算器有计算功能+-*/就行越简单越好！！！急！！！
class Helloworld
{
public static void main(String[] args)
{
System.out.println("Hello World!");
}
}
这个最简单，记得存为Helloworld.java才行
package wanwa;import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Calculator extends JFrame {
private Container container;
private GridBagLayout layout;
private GridBagConstraints constraints;
private JTextField displayField;
private String lastCommand;
private double result;
private boolean start;
public Calculator() {
super("计算器"); container = getContentPane();
layout = new GridBagLayout();
container.setLayout(layout);
constraints = new GridBagConstraints();
start = true;
result = 0;
lastCommand = "=";
displayField = new JTextField(20);
displayField.setHorizontalAlignment(JTextField.RIGHT);
constraints.gridx = 0;
constraints.gridy = 0;
constraints.gridwidth = 4;
constraints.gridheight = 1;
constraints.fill = GridBagConstraints.BOTH;
constraints.weightx = 100;
constraints.weighty = 100;
layout.setConstraints(displayField, constraints);
container.add(displayField);
ActionListener insert = new InsertAction();
ActionListener command = new CommandAction();
addButton("Backspace", 0, 1, 2, 1, insert);
addButton("CE", 2, 1, 1, 1, insert);
addButton("C", 3, 1, 1, 1, insert);
addButton("7", 0, 2, 1, 1, insert);
addButton("8", 1, 2, 1, 1, insert);
addButton("9", 2, 2, 1, 1, insert);
addButton("/", 3, 2, 1, 1, command);
addButton("4", 0, 3, 1, 1, insert);
addButton("5", 1, 3, 1, 1, insert);
addButton("6", 2, 3, 1, 1, insert);
addButton("*", 3, 3, 1, 1, command);
addButton("1", 0, 4, 1, 1, insert);
addButton("2", 1, 4, 1, 1, insert);
addButton("3", 2, 4, 1, 1, insert);
addButton("-", 3, 4, 1, 1, command);
addButton("0", 0, 5, 1, 1, insert);
addButton(".", 2, 5, 1, 1, insert);
addButton("+", 3, 5, 1, 1, command);
addButton("=", 1, 5, 1, 1, command);
this.setResizable(true);
setSize(180, 200);
setVisible(true);
}
private void addButton(String label, int row, int column, int with, int height, ActionListener listener) {
JButton button = new JButton(label);
constraints.gridx = row;
constraints.gridy = column;
constraints.gridwidth = with;
constraints.gridheight = height;
constraints.fill = GridBagConstraints.BOTH;
button.addActionListener(listener);
layout.setConstraints(button, constraints);
container.add(button);
}
private class InsertAction implements ActionListener { public void actionPerformed(ActionEvent event) {
String input = event.getActionCommand();
if (start) {
displayField.setText("");
start = false;
if (input.equals("+/-"))
displayField.setText(displayField.getText() + "-");
}
if (!input.equals("+/-")) {
if (input.equals("Backspace")) {
String str = displayField.getText();
if (str.length() > 0)
displayField.setText(str.substring(0, str.length() - 1));
}
else if (input.equals("CE") || input.equals("C")) {
displayField.setText("0");
start = true;
} else
displayField.setText(displayField.getText() + input);
}
}
}
private class CommandAction implements ActionListener { public void actionPerformed(ActionEvent evt) {
String command = evt.getActionCommand();
if (start) {
lastCommand = command;
}
else {
calculate(Double.parseDouble(displayField.getText()));
lastCommand = command;
start = true;
}
}
}
public void calculate(double x) { if (lastCommand.equals("+"))
result += x;
else if (lastCommand.equals("-"))
result -= x;
else if (lastCommand.equals("*"))
result *= x;
else if (lastCommand.equals("/"))
result /= x;
else if (lastCommand.equals("="))
result = x;
displayField.setText("" + result);
}
public static void main(String[] args) { Calculator calculator = new Calculator();
calculator.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
String st = "";
计算器 j = new 计算器();
boolean t = true;
while (t) {
System.out.print("请输入计算代码：");
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
try {
st = br.readLine();
} catch (IOException ex) {
Logger.getLogger(计算器.class.getName()).log(Level.SEVERE, null, ex);
}
if (st.equals("end")) {
t = false;
} else if (!st.equals("")) {
j.处理(st);
}
}
}
public void 处理(String st) {
if (st.indexOf("+") != -1) {
加(符号处理(st, "+"));
} else if (st.indexOf("-") != -1) {
减(符号处理(st, "-"));
} else if (st.indexOf("*") != -1) {
乘(符号处理(st, "*"));
} else if (st.indexOf("/") != -1) {
除(符号处理(st, "/"));
}
}
public int[] 符号处理(String st, String s) {
int[] i = new int[2];
i[0] = Integer.parseInt(st.substring(0, st.indexOf(s)));
i[1] = Integer.parseInt(st.substring(st.indexOf(s) + 1));
return i;
}
public void 加(int x[]) {
System.out.println(x[0] + "+" + x[1] + "=" + (x[0] + x[1]));
}
public void 减(int[] x) {
System.out.println(x[0] + "-" + x[1] + "=" + (x[0] - x[1]));
}
public void 乘(int[] x) {
System.out.println(x[0] + "*" + x[1] + "=" + x[0] * x[1]);
}
public void 除(int x[]) {
if (x[1] == 0) {
System.out.print("除数不能为零");
return;
}
System.out.println(x[0] + "/" + x[1] + "=" + x[0] / x[1]);
}
可以运行：输入示例：55+62
请留下Email地址 ，代码仅供参考 希望自己多练习
public class Calculator {
double sum=0;
public double ope(int op,int num1,int num2){
switch(op){
case 1:
sum=num1+num2;
break;
case 2:
sum=num1-num2;
break;
case 3:
sum=num1/num2;
break;
case 4:
sum=num1*num2;
break;
default:
System.out.println("请输入正确的运算符");
}
return sum;
}
}
import java.util.*;
public class test1 {
public static void main(String[]args){
Scanner input=new Scanner(System.in);
Calculator c=new Calculator();
System.out.println("请选择运算符：1.加法 2.减法 3.除法 4.乘法");
int op=input.nextInt();
System.out.println("请输入第一个数：");
int num1=input.nextInt();
System.out.println("请输入第二个数：");
int num2=input.nextInt();
double sum=c.ope(op, num1, num2);
System.out.println("***运算结果为："+sum);
}
}
我也是初学JAVA的 见笑
public class calculator{
//加法
public int add(int number1,int number2){
return (number1+number2);
}
//减法
public int subtract(int number1,int number2){
return (number1-number2);
}
//乘法
public int multiplicat(int number1,int number2){
return (number1*number2);
}
//除法
public int div(int number1,int number2){
return (number1/number2);
}
public static void main(String[] args) {
int number1=6;
int number2=3;
System.out.println("6+3="+add(number1,number2));
System.out.println("6-3="+subtract(number1,number2));
System.out.println("6*3="+multiplicat(number1,number2));
System.out.println("6/3="+div(number1,number2));
}
}
纯手打，不知道能不能运行，你可以直接复制下来试试。
我觉得是不是可以把算式写成字符串通过args[]传入（方便cmd里 用java Yunsuan 1+2*3-4之类的使用），然后把字符串用split按照运算优先顺序通过运算符进行逐层分割，分解成一个一个的数组，最后通过switch 运算符的办法进行一步一步的化简，直到得到最终结果呢？刚开始学，希望讨论下
好吧，我自己写了个简单的，还不能用括号和三角函数等等，以后加上动态数组的知识应该可以简化下代码，我还没学到呢……这也相当于一个简单的eval了：cmd里编译以后，运行java后边跟上算式即可。例如 java Jisuan 1+2*3-5/2
import java.lang.Number;
class Jisuan
{
static String s="";
public static void main(String[] args)
{
for (int i=0;i<args.length ;i++ )
{s=s+args[i];}
s="0+"+s;//s=算式
String shuzi[]=s.split("\\+|\\-|\\*|\\/");//分隔得到数字
char youxian[]={'*','/','-','+'};
char fuhao[]=new char[shuzi.length];
int sum=0;
for (int i=0;i<shuzi.length-1 ;i++ )
{
sum=sum+shuzi[i].length();
fuhao[i]=s.charAt(sum+i);//取位得到运算符号
}
for (int i=0;i<youxian.length ;i++ )//化简算式
{
for (int j=1;j<=fuhao.length-1;j++ )
{
if (fuhao[j]==youxian[i])
{
shuzi[j+1]=js(shuzi[j],fuhao[j],shuzi[j+1]);//求结果
for (int l=j;l>=1;l-- )
{
fuhao[l]=fuhao[l-1];
shuzi[l]=shuzi[l-1];
}
}
}
}
System.out.println("="+shuzi[shuzi.length-1]);
}
public static String js(String a,char b,String c)
{
Double e=0.0;
switch (b)
{
case '+':
e=Double.valueOf(a)+Double.valueOf(c);break;
case '-':
e=Double.valueOf(a)-Double.valueOf(c);break;
case '*':
e=Double.valueOf(a)*Double.valueOf(c);break;
case '/':
e=Double.valueOf(a)/Double.valueOf(c);break;
}
return Double.toString(e);
}
}
http://hi.baidu.com/shy2850/blog/item/707e0f1365e6fad5c3fd78c1.html
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