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java四则运算,Java四则运算正确率怎么算

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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("");

}

}

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:

  Scanner s = new Scanner(System.in);//接受键盘输入的数值。

  int str = s.next();//将输入的字符串转换为int类型,就可以进行四则运算。

java的四则运算

import java.util.Scanner;

public class SimpleCalc {

    public SimpleCalc() {}

    

    public static void main(String[] args) {

        calc();

    }

    

    public static void calc() {

        Scanner reader = new Scanner(System.in);

        char op;

        double num1, 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;

                    case 0://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) {

                            case 1:

                                result = num1 + num2;

                                break;

                            case 2:

                                result = num1 - num2;

                                break;

                            case 3:

                                result = num1 * num2;

                                break;

                            case 4:

                                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(Exception err) {

                        System.out.println("输入非法!");

                    }

                    if (!isContinue(reader)) {

                        break;

                    }

                }

            }

        }

    }

    

    public static boolean isContinue(Scanner reader) {

        boolean flag = false;

        

        if (reader.hasNext()) {

            char isContinue = reader.next().charAt(0);

            

            if ('N' == isContinue) {

                flag = false;

            } else if ('Y' == isContinue) {

                flag = true;

            } else {

                System.out.println("是否继续?是(Y)/否(N):");

                flag = isContinue(reader);

            }

        }

        

        return flag;

    }

}

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 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简单的四则运算.

public class Arithmetic {

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。