java实现四则运算

1. 如何让java以传入参数的方法实现简单四则运算

// String str = args[0];
// 模拟输入
// 获取输入的内容
String str = "1.1+2";
if (str.contains("+")) {
String[] strs = str.split("\\+");
double arg1 = Double.valueOf(strs[0]);
double arg2 = Double.valueOf(strs[1]);
System.out.println(arg1 + arg2);
}
str = "1.1-2";
if (str.contains("-")) {
String[] strs = str.split("\\-");
double arg1 = Double.valueOf(strs[0]);
double arg2 = Double.valueOf(strs[1]);
System.out.println(arg1 - arg2);
}
str = "1.1*2";
if (str.contains("*")) {
String[] strs = str.split("\\*");
double arg1 = Double.valueOf(strs[0]);
double arg2 = Double.valueOf(strs[1]);
System.out.println(arg1 * arg2);
}
str = "1.1/2";
if (str.contains("/")) {
String[] strs = str.split("\\/");
double arg1 = Double.valueOf(strs[0]);
double arg2 = Double.valueOf(strs[1]);
System.out.println(arg1 / arg2);
}
写的比较死。不然的话可能需要其他工具类的支持。

2. java实现四则运算

最后一个提示没看懂意思。import java.util.Random;
public class JiS {
public static void main(String[] args)
{
Random r=new Random();
char[]ch=new char[]{'+','-','*','/'};
boolean flag=true;
while(flag){
int a=r.nextInt(10001);
int b=r.nextInt(10001);
char c=ch[r.nextInt(ch.length)];
// System.out.println(a+","+b+","+c);
switch(c)
{
case '+':
if(a+b<=10000){System.out.println(a+"+"+b+"="+(a+b));flag=false;}
break;
case '-':
if(a-b>=0){System.out.println(a+"-"+b+"="+(a-b));flag=false;}
break;
case '*':
if(a*b<=10000){System.out.println(a+"*"+b+"="+a*b);flag=false;}
break;
case '/':
if(b!=0){System.out.println(a+"/"+b+"="+a/b);flag=false;}
break;
}
}
}
}

3. 用java编写四则运算（要求多个类，字节编写）

importjavax.swing.*;
importjava.awt.*;
importjava.awt.event.*;

{
	=1L;
	JTextFieldtext1,text2;
	JButtonbut1,but2,but3,but4;
	JLabellab1;

	publicBuju(){
		super("布局模式");
		setBounds(20,20,500,400);
		ContainercontentPane=getContentPane();
		contentPane.setLayout(newBorderLayout(10,10));
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		JPaneljp1=newJPanel(newFlowLayout());
		JPaneljp2=newJPanel(newFlowLayout());

		text1=newJTextField(5);
		text2=newJTextField(5);
		lab1=newJLabel("输出结");

		jp2.add(text1);
		jp2.add(text2);
		jp2.add(lab1);
		
		but1=newJButton("+");
		but2=newJButton("-");
		but3=newJButton("*");
		but4=newJButton("/");
		but1.addActionListener(this);
		but2.addActionListener(this);
		but3.addActionListener(this);
		but4.addActionListener(this);

		jp1.add(but1);
		jp1.add(but2);
		jp1.add(but3);
		jp1.add(but4);
		
		contentPane.add(jp2,BorderLayout.CENTER);
		contentPane.add(jp1,BorderLayout.SOUTH);
	}

	publicvoidactionPerformed(java.awt.event.ActionEventevt){
		doublex,y,s;
		Stringstr;
		x=Double.valueOf(text1.getText());
		y=Double.valueOf(text2.getText());
		
		if(evt.getSource()==but1){
			s=x+y;
			str=String.valueOf(s);
			lab1.setText(str);	
		}
		if(evt.getSource()==but2){
			s=x-y;
			str=String.valueOf(s);
			lab1.setText(str);	
		}
		if(evt.getSource()==but3){
			s=x*y;
			str=String.valueOf(s);
			lab1.setText(str);	
		}
		if(evt.getSource()==but4){
			s=x/y;
			str=String.valueOf(s);
			lab1.setText(str);	
		}
	}

	publicstaticvoidmain(String[]args){
		Bujubj=newBuju();
		bj.setVisible(true);
	}
}

结果运行：

4. 请用java编写一个计算四则运算的方法

计算器的最好的算法将中缀表达式转换为后缀表达式，楼主可以搜索以下相关资料 ，
也可以 char[] c = xString.toCharArray(); 然后通过 asc 码来比较，不果逻辑不好控制

5. java的四则运算

importjava.util.Scanner;

publicclassSimpleCalc{
publicSimpleCalc(){}

publicstaticvoidmain(String[]args){
calc();
}

publicstaticvoidcalc(){
Scannerreader=newScanner(System.in);
charop;
doublenum1,num2,result;

while(true){
System.out.println("请选择运算符:1、+;2、-;3、*;4、/");
if(reader.hasNext()){
op=reader.nextChar();
switch(op){
case'1':
op=1;
break;
case'2':
op=2;
break;
case'3':
op=3;
break;
case'4':
op=4;
break;
case0://EOF
default:
System.out.println("输入非法！");
op=0;
break;
}
if(0!=op){
try{
System.out.println("请输入第一个运算数:");
if(reader.hasNext()){
num1=reader.nextDouble();
}
System.out.println("请输入第二个运算数:");
if(reader.hasNext()){
num2=reader.nextDouble();
}
switch(op){
case1:
result=num1+num2;
break;
case2:
result=num1-num2;
break;
case3:
result=num1*num2;
break;
case4:
result=num1/num2;
break;
}
System.out.println("运算结果为:"+result);
System.out.println("是否继续？是(Y)/否(N):");
}catch(Exceptionerr){
System.out.println("输入非法！");
}
if(!isContinue(reader)){
break;
}
}
}
}
}

publicstaticbooleanisContinue(Scannerreader){
booleanflag=false;

if(reader.hasNext()){
charisContinue=reader.next().charAt(0);

if('N'==isContinue){
flag=false;
}elseif('Y'==isContinue){
flag=true;
}else{
System.out.println("是否继续？是(Y)/否(N):");
flag=isContinue(reader);
}
}

returnflag;
}
}

6. java用按钮实现四则运算

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

public class TestResult extends JFrame implements ActionListener{
JTextField jfforward,jfcenter,jfbehind;
JButton jequals;
JComboBox list;
TestResult(){
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setLayout(new FlowLayout());
jfforward = new JTextField(8);
jfcenter = new JTextField(8);
jfbehind = new JTextField(8);
jequals = new JButton("=");
list = new JComboBox();
setTitle("四则运算");
list.addItem("+");
list.addItem("-");
list.addItem("*");
list.addItem("/");
add(jfforward);
add(list);
add(jfcenter);
add(jequals);
add(jfbehind);
jequals.addActionListener(this);
this.setResizable(false);
this.setSize(500, 500);
this.setVisible(true);

}

public static void main(String[] args) {
new TestResult();
}

public void actionPerformed(ActionEvent e) {
if(e.getSource()==jequals){
switch(list.getSelectedIndex()){
case 0:{
int n = Integer.parseInt(jfforward.getText());
int m = Integer.parseInt(jfcenter.getText());
int sum=n+m;
jfbehind.setText(""+sum);
}
break;
case 1:{
int n = Integer.parseInt(jfforward.getText());
int m = Integer.parseInt(jfcenter.getText());
int sum=n-m;
jfbehind.setText(""+sum);
}
break;
case 2:{
int n = Integer.parseInt(jfforward.getText());
int m = Integer.parseInt(jfcenter.getText());
int sum=n*m;
jfbehind.setText(""+sum);
}
break;
case 3:{
int n = Integer.parseInt(jfforward.getText());
int m = Integer.parseInt(jfcenter.getText());
int sum=n/m;
jfbehind.setText(""+sum);
}
break;
}
}

}

}
基本符合要求,我也不，就是照着书再加上自己的一点思路做的，其实你也可以
不够健壮

7. 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("");

}

}

8. 定义一个方法，实现四则运算的功能。java

import java.text.DecimalFormat;
import java.util.Scanner;

public class Zhi {

public static void main(String[] args) {
String condition = "";
Zhi = new Zhi();
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);
.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");
}
}

}

9. Java中怎么能实现从键盘输入几个数字后进行四则运算

Java中提供了一个Scanner类，接受用户从键盘敲入的数值，具体 使用例子如下：

Scanners=newScanner(System.in);//接受键盘输入的数值。
intstr=s.next();//将输入的字符串转换为int类型，就可以进行四则运算。