java控制台计算器代码 JAVA计算器代码

Java写一个计算器控制台输入算式可以实现先乘除后加减没有括号功能只有加减乘除

你自己研究下，这个代码，别人写的：

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import java.util.Scanner;

public class T {

public static void main(String[] args) {

Scanner scan = new Scanner(System.in);

//String str = "54151+819*5165+15-48/189+5961";

System.out.println("请输入算式，按回车键结束：");

String str = scan.nextLine();

System.out.println(cacComplex(str));

}

private static double cacComplex(String str) {

if (str.equals(""))

return 0;

System.out.println("CAC:" + str);

str = str.replaceAll("[\\[\\{]", "(").replaceAll("[\\]\\}]", ")");

int cl = str.lastIndexOf('(');

if (cl == -1)

return cac(str);

int cr = str.indexOf(')', cl);

String left = str.substring(0, cl);

String right = str.substring(cr + 1);

String middle = str.substring(cl + 1, cr);

return cacComplex(left + cac(middle) + right);

}

public static double cac(String str) {

if (str.equals(""))

return 0;

int ml = str.indexOf('*');

int dl = str.indexOf('/');

if (ml == -1 dl == -1) {

return cacNoMD(str);

}

int index = ml == -1 ? dl : ml;

// 4+5*6*7+8

String left = str.substring(0, index);// 4+5

String m1 = lastNumber(left);

left = left.substring(0, left.length() - m1.length());

String right = str.substring(index + 1);// 6*7+8

String m2 = firstNumber(right);// m2:6

right = right.substring(m2.length());// *7+8

double d1 = Double.parseDouble(m1);

double d2 = Double.parseDouble(m2);

double tmp = 0;

if (index == ml) {

tmp = d1 * d2;

} else if (index == dl) {

tmp = d1 / d2;

}

return cac(left + tmp + right);

}

private static String lastNumber(String str) {

StringBuilder sb = new StringBuilder();

for (int i = str.length() - 1; i = 0; i--) {

char c = str.charAt(i);

if (!Character.isDigit(c) c != '.')

break;

sb.append(c);

}

return sb.reverse().toString();

}

private static String firstNumber(String str) {

StringBuilder sb = new StringBuilder();

for (char c : str.toCharArray()) {

if (!Character.isDigit(c) c != '.')

break;

sb.append(c);

}

return sb.toString();

}

private static double cacNoMD(String str) {

double ret = 0;

StringBuilder sb = new StringBuilder();

char sign = '+';

for (char c : (str + "+").toCharArray()) {

if (!Character.isDigit(c) c != '.') {

if (sb.length() == 0)

continue;

double tmp = Double.parseDouble(sb.toString());

if (sign == '+') {

ret += tmp;

} else {

ret -= tmp;

}

sb = new StringBuilder();

sign = c;

} else {

sb.append(c);

}

return ret;

}

请输入算式，按回车键结束：

54151+819*5165+15-48/189+5961

CAC:54151+819*5165+15-48/189+5961

4290261.746031746

用JAVA编写一个简单的计算器，要求如下:

然后通过输入显示结果，比如说：

以下是上图计算器的代码:

package Computer;

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.Container;

import java.awt.Font;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.util.Stack;

import javax.swing.JApplet;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.JTextField;

public class Count extends JApplet implements ActionListener

{

/**

private static final long serialVersionUID = 1L;

private JTextField textField = new JTextField("请输入");

String operator = "";//操作

String input = "";//输入的式子

boolean flag = true;

// boolean flag1 = true;

// boolean flag2 = true;

public void init()//覆写Applet里边的init方法

{

Container C = getContentPane();

JButton b[] = new JButton[16];

JPanel panel = new JPanel();

C.add(textField, BorderLayout.NORTH);

C.add(panel,BorderLayout.CENTER);

panel.setLayout(new GridLayout(4, 4,5,5));

String name[]={"7","8","9","+","4","5","6","-","1","2","3","*","0","C","=","/"};//设置按钮

for(int i=0;i16;i++)//添加按钮

{

b[i] = new JButton(name[i]);

b[i].setBackground(new Color(192,192,192));

b[i].setForeground(Color.BLUE);//数字键设置为蓝颜色

if(i%4==3)

b[i].setForeground(Color.RED);

b[i].setFont(new Font("宋体",Font.PLAIN,16));//设置字体格式

panel.add(b[i]);

b[i].addActionListener(this);

}

b[13].setForeground(Color.RED);//非数字键，即运算键设置为红颜色

b[13].setForeground(Color.RED);

}

public void actionPerformed(ActionEvent e)

{

int cnt = 0;

String actionCommand = e.getActionCommand();

if(actionCommand.equals("+")||actionCommand.equals("-")||actionCommand.equals("*") ||actionCommand.equals("/"))

input +=" "+actionCommand+" ";//设置输入，把输入的样式改成需要的样子

else if(actionCommand.equals("C"))

input = "";

else if(actionCommand.equals("="))//当监听到等号时，则处理 input

{

input+= "="+compute(input);

textField.setText(input);

input="";

cnt = 1;

}

else

input += actionCommand;//数字为了避免多位数的输入不需要加空格

if(cnt==0)

textField.setText(input);

}

private String compute(String input)//即1237 的样例

{

String str[];

str = input.split(" ");

StackDouble s = new StackDouble();

double m = Double.parseDouble(str[0]);

s.push(m);

for(int i=1;istr.length;i++)

{

if(i%2==1)

{

if(str[i].compareTo("+")==0)

{

double help = Double.parseDouble(str[i+1]);

s.push(help);

}

if(str[i].compareTo("-")==0)

{

double help = Double.parseDouble(str[i+1]);

s.push(-help);

}

if(str[i].compareTo("*")==0)

{

double help = Double.parseDouble(str[i+1]);

double ans = s.peek();//取出栈顶元素

s.pop();//消栈

ans*=help;

s.push(ans);

}

if(str[i].compareTo("/")==0)

{

double help = Double.parseDouble(str[i+1]);

double ans = s.peek();

s.pop();

ans/=help;

s.push(ans);

}

double ans = 0d;

while(!s.isEmpty())

{

ans+=s.peek();

s.pop();

}

String result = String.valueOf(ans);

return result;

}

public static void main(String args[])

{

JFrame frame = new JFrame("Count");

Count applet = new Count();

frame.getContentPane().add(applet, BorderLayout.CENTER);

applet.init();//applet的init方法

applet.start();//线程开始

frame.setSize(350, 400);//设置窗口大小

frame.setVisible(true);//设置窗口可见

}

使用java实现一个控制台计算器程序。

不太完善，你再加点输入的逻辑判断什么的，这个演示只能输入正确的数据才能运行，否则会报错，仅供参考。（求采纳啊）

public class C {

static Double rs;

public static Double yunsuan(String r,Double a1, Double a2){

Double result;

if(r.equals("+")){

result=a1+a2;