java代码编写四则运算 javabean实现四则运算
java简单的四则运算.
public class Arithmetic {
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public static void Ari(){
Scanner scan = new Scanner(System.in);
StringBuffer buffer = new StringBuffer();
DecimalFormat dec = new DecimalFormat("0.00");//格式化结果保留两位小数
String all = "";//所有的计算表达式连在一起
System.out.println("请输入表达式的个数,只能为正整数");
int n = scan.nextInt();
System.out.println("请依次输入要计算的表达式");
for(int i=0;in+1;i++){
buffer = buffer.append(scan.nextLine()+",");
}
all = buffer.substring(0, buffer.lastIndexOf(","));
String allAri[] = all.split(",");
String ari = "";//不同的算法表达式
float add;//加法的计算结果
float subtract;//减肥的计算结果
float multi;//乘法的计算结果
float divison;//除法的计算结果
int model;//模运算的计算结果
for(int j=0;jallAri.length;j++){
ari = allAri[j];
if(ari.contains("+")){
String tempAry[] = ari.split("[+]");
add = Float.valueOf(tempAry[0])+Float.valueOf(tempAry[1]);
System.out.println(dec.format(add));
}else if(ari.contains("-")){
String tempAry[] = ari.split("[-]");
subtract = Float.valueOf(tempAry[0])-Float.valueOf(tempAry[1]);
System.out.println(dec.format(subtract));
}else if(ari.contains("*")){
String tempAry[] = ari.split("[*]");
multi = Float.valueOf(tempAry[0])*Float.valueOf(tempAry[1]);
System.out.println(dec.format(multi));
}else if(ari.contains("/")){
String tempAry[] = ari.split("[/]");
divison = Float.valueOf(tempAry[0])/Float.valueOf(tempAry[1]);
System.out.println(dec.format(divison));
}else if(ari.contains("%")){
String tempAry[] = ari.split("[%]");
model = Integer.valueOf(tempAry[0])%Integer.valueOf(tempAry[1]);
System.out.println(model);
}
}
}
public static void main(String[] args) {
Ari();
}
}
测试结果截图如下:
你的测试用例的输入的表达式的个数是4个,但下面的计算表达式好像少了一个,所以我加了一个除法的计算表达式,若理解有误,还望说明。
编写一个实现四则运算的JAVA程序
import java.text.DecimalFormat;
import java.util.Scanner;
public class Zhidao {
public static void main(String[] args) {
String condition = "";
Zhidao zhidao = new Zhidao();
do{
Scanner scanner = new Scanner(System.in);
try{
System.out.print("请输入第一个数:");
double x = scanner.nextDouble();
System.out.print("请输入第二个数:");
double y = scanner.nextDouble();
System.out.print("请输入运算符:");
String s = scanner.next();
char z = s.charAt(0);
zhidao.yunsuan(x, y, z);
}catch(Exception e){
System.out.println("请输入正确的数据!");
}
System.out.print("是否继续?continue:继续,任意字符:结束");
condition = scanner.next();
}while("continue".equals(condition));
}
public static void yunsuan(double x,double y,Character z){
DecimalFormat r=new DecimalFormat();
r.applyPattern("#0.00");
if(z.equals('+')){
System.out.println(x+"+"+y+"=" + r.format((x+y)));
} else if(z.equals('-')){
System.out.println(x+"-"+y+"=" + r.format((x-y)));
} else if(z.equals('*')){
System.out.println(x+"*"+y+"=" + r.format((x*y)));
} else if(z.equals('/')){
if(y==0){
System.out.println("被除数不能为0");
} else{
System.out.println(x+"/"+y+"=" + r.format((x/y)));
}
}else{
System.out.println("无法识别改运算符");
}
}
}
java四则运算
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class calculator extends JFrame implements ActionListener {
private boolean i=true,clickable = true ;//这里的clickabel 是用来判断小数点的 如果有小数点的话 clickable则为false就不对小数点进行添加了 i在下面有解释
private double value=0; //这个就是显示出来的值了
String operate = "="; //操作数 默认情况下是=号
JFrame jframe=new JFrame("计算机");
JTextField text1=new JTextField("0");
JButton back = new JButton("退格");
JButton daoshu = new JButton("1/x");
JButton remain = new JButton("%");
JButton PI = new JButton("PI"); //显示圆周率小数点后7位
JButton square = new JButton("x^2");
JButton cube = new JButton("x^3");
JButton plu=new JButton("+");
JButton min=new JButton("-");
JButton mul=new JButton("*");
JButton equ=new JButton("=");
JButton div=new JButton("/");
JButton code=new JButton("+/-");
JButton point=new JButton(".");
JButton num1=new JButton("1");
JButton num2=new JButton("2");
JButton num3=new JButton("3");
JButton num4=new JButton("4");
JButton num5=new JButton("5");
JButton num6=new JButton("6");
JButton num7=new JButton("7");
JButton num8=new JButton("8");
JButton num9=new JButton("9");
JButton num0=new JButton("0");
JButton num00=new JButton("00");
JButton clear=new JButton("C");
calculator(){
jframe.setSize(400, 400);
jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel p=new JPanel();
p.setBackground(Color.gray);
p.setLayout(new GridLayout(5, 5)); //采用的布局方式为网格布局
PI.addActionListener(this);
daoshu.addActionListener(this);
remain.addActionListener(this);
square.addActionListener(this);
cube.addActionListener(this);
plu.addActionListener(this);
equ.addActionListener(this);
num1.addActionListener(this);
num2.addActionListener(this);
clear.addActionListener(this);
num3.addActionListener(this);
num4.addActionListener(this);
num5.addActionListener(this);
num6.addActionListener(this);
num7.addActionListener(this);
num8.addActionListener(this);
num9.addActionListener(this);
num0.addActionListener(this);
num00.addActionListener(this);
min.addActionListener(this);
code.addActionListener(this);
div.addActionListener(this);
point.addActionListener(this);
mul.addActionListener(this);
back.addActionListener(this);
jframe.add(p);
p.add(PI);
p.add(code);
p.add(daoshu);
p.add(back);
p.add(clear);
p.add(num7);
p.add(num8);
p.add(num9);
p.add(plu);
p.add(remain);
p.add(num4);
p.add(num5);
p.add(num6);
p.add(min);
p.add(square);
p.add(num1);
p.add(num2);
p.add(num3);
p.add(mul);
p.add(cube);
p.add(num0);
p.add(num00);
p.add(point);
p.add(div);
p.add(equ);
jframe.add(text1,"North");
jframe.setLocation(300, 300);
jframe.setVisible(true);
}
public void actionPerformed(ActionEvent evt)
{
String str1,str2;
Object soc=evt.getSource();
String s = evt.getActionCommand(); //获取按钮的数据
if(soc==back){ //进行退格操作
str1=text1.getText();
int n=str1.length();
text1.setText(str1.substring(0,n-1));
str2 = text1.getText();
}
else if (s.equals("x^2")) {
str1=text1.getText();
double k = Double.parseDouble(str1);
k *=k;
text1.setText(String.valueOf(k));
}
else if (s.equals("x^3")) {
str1=text1.getText();
double k = Double.parseDouble(str1);
k =k*k*k;
text1.setText(String.valueOf(k));
}
else if(s.equals("PI")){ //显示圆周率
double Pi=3.1415926;
String pi=String.valueOf(Pi);
text1.setText(pi);
}
else if(s.equals("+/-")){ //变换正负号
double a = 0;
str1=text1.getText();
a=Double.parseDouble(str1.trim());
a=-1*a;
str1=String.valueOf(a);
text1.setText(str1);
}
else if(s.equals("1/x")){ //求倒
str1=text1.getText();
double i = 1/Double.parseDouble(str1.trim());
String k = String.valueOf(i);
text1.setText(k);
}
else if(s.equals(".")){ //小数点
clickable=true;
for (int i = 0; i text1.getText().length(); i++)
if ('.' == text1.getText().charAt(i))
{
clickable=false;
break;
} //第一层判断是否里面含有小数点;
if(clickable==true) //第二层判断
text1.setText(text1.getText()+".");
i=false;
}
else if(s.equals("C")){ //清零 所有的数据变回初始值
value = 0;
text1.setText("0");
i=true;
operate = "=" ;
}
else if ('0' = s.charAt(0) s.charAt(0) = '9' ) { //若输入的为数字以及小数点的时候执行下面
if (i) { //判断获得的command是否为操作符
text1.setText(s);
}
else {
text1.setText(text1.getText() + s);
}
i = false;
}
else { //若输入运算操作符的话则执行下面的代码
count(Double.parseDouble(text1.getText().trim())); //这里一开始调用 count()方法的话首先执行的是operate.equals("=")
//执行上个操作符的运算
operate = s;
i = true;
}
}
private void count(double a) { //计算区域
if (operate.equals("+")) {
value += a;
}
else if (operate.equals("-")) {
value -= a;
}
else if (operate.equals("*")) {
value *= a;
}
else if (operate.equals("/")) {
value /= a;
}
else if (operate.equals("%")) {
value %= a;
}
else if (operate.equals("=")) {
value = a;
}
text1.setText(Double.toString(value));
}
public static void main(String[] arg)
{
calculator cal=new calculator();
}
}
这是例子 你可以参考下~监听的 部分
如何用Java编写四则运算程序?
(首先建个类,把这些复制粘贴进去)
import java.awt.*;
import javax.swing.*;
public class F {
JFrame frame = new JFrame("计算机");
JPanel pl = new JPanel();
JPanel p2 = new JPanel();
static JTextField show = new JTextField();
static JButton b0 = new JButton("0");
static JButton b1 = new JButton("1");
static JButton b2 = new JButton("2");
static JButton b3 = new JButton("3");
static JButton b4 = new JButton("4");
static JButton b5 = new JButton("5");
static JButton b6 = new JButton("6");
static JButton b7 = new JButton("7");
static JButton b8 = new JButton("8");
static JButton b9 = new JButton("9");
JButton bjia = new JButton("+");
JButton bjian = new JButton("-");
JButton bcheng = new JButton("*");
JButton bchu = new JButton("/");
JButton bdian = new JButton(".");
JButton bdeng = new JButton("=");
JButton bqingchu = new JButton("清除");
public void y() {
pl.setLayout(new GridLayout(1, 1));
pl.add(show);
}
public void p() {
b1.addActionListener(new U());
b2.addActionListener(new U());
b3.addActionListener(new U());
b4.addActionListener(new U());
b5.addActionListener(new U());
b6.addActionListener(new U());
b7.addActionListener(new U());
b8.addActionListener(new U());
b9.addActionListener(new U());
b0.addActionListener(new U());
bjia.addActionListener(new Fu());
bjian.addActionListener(new Fu());
bcheng.addActionListener(new Fu());
bchu.addActionListener(new Fu());
bdeng.addActionListener(new Deng());
bqingchu.addActionListener(new Qing());
p2.setLayout(new GridLayout(6, 3));
p2.add(b1);
p2.add(b2);
p2.add(b3);
p2.add(b4);
p2.add(b5);
p2.add(b6);
p2.add(b7);
p2.add(b8);
p2.add(b9);
p2.add(b0);
p2.add(bjia);
p2.add(bjian);
p2.add(bcheng);
p2.add(bchu);
p2.add(bdian);
p2.add(bqingchu);
p2.add(bdeng);
}
public void o() {
frame.setLayout(new BorderLayout());
frame.add(pl, BorderLayout.NORTH);
frame.add(p2, BorderLayout.CENTER);
frame.setSize(400, 300);
frame.setVisible(true);
}
public static void main(String[] args) {
F f = new F();
f.y();
f.p();
f.o();
}
}
(再新建个类 把这些也复制粘贴进去)
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class U implements ActionListener {
public static String str = "";
public static String a = "";
public static String b = "";
public static String k = "";
public void actionPerformed(ActionEvent e) {
String w = e.getActionCommand();//字
if (k.equals("")) {
a += w;
F.show.setText(a);
} else {
b += w;
F.show.setText(b);
}
}
}
(再新建一个,把下面的复制粘贴)
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Deng implements ActionListener {
public void actionPerformed(ActionEvent e) {
int a = Integer.parseInt(U.a);
int b = Integer.parseInt(U.b);
int c = 0;
if (U.k.equals("+")) {
c = a + b;
} else
if (U.k.equals("-")) {
c = a - b;
} else
if (U.k.equals("*")) {
c = a * b;
} else
if (U.k.equals("/")) {
c = a / b;
} else {
}
String d = String.valueOf(c);
F.show.setText(d);
U.a = d;
U.b = "";
U.k = "";
}
}
(在建一个 复制粘贴)
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Fu implements ActionListener {
public void actionPerformed(ActionEvent e) {
String a = e.getActionCommand();//字
U.k = a;
}
}
(在建一个)
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Qing implements ActionListener {
public void actionPerformed(ActionEvent e) {
U.a = "";
U.b = "";
U.k = "";
F.show.setText("");
}
}
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