java中运算器的代码 java四则运算代码

java:抽象类和接口实现四则运算器

import java.util.*;

interface yunsuan

{

public int jia();

public int jian();

public int cheng();

public int chu();

}

class Example implements yunsuan

{

int x,y;

public Example(int x,int y)

{

this.x=x;

this.y=y;

}

public int jia()

{

return x+y;

}

public int jian()

{

return x-y;

}

public int cheng()

{

return x*y;

}

public int chu()

{

return x/y;

}

}

public class ag

{

public static void main(String []args)

{

Scanner in=new Scanner(System.in);

System.out.println("输入第一个数");

int a=in.nextInt();

System.out.println("输入第二个数");

int b=in.nextInt();

System.out.println("输入运算符");

String c=in.next();

Example ys=new Example(a,b);

if(c.equals("+"))

{System.out.print(ys.jia());}

else if(c.equals("-"))

{System.out.print(ys.jian());}

else if(c.equals("*"))

{System.out.print(ys.cheng());}

else if(c.equals("/"))

{System.out.print(ys.chu());}

}

}

相关问答

Q1: 稀疏矩阵运算 Java``小问题

只写了相加方法，相减类似，乘法需要另外处理

/**

*

* 表示矩阵的单个元素的三元组，row行号，col列号，val元素值

* compareTo方法比较两个元素位置（按行号优先）返回-1（位置在之前），0（相同位置），1（位置在之后）

*/

class Trituple implements ComparableTrituple

{

int row;

int col;

double val;

public Trituple(int row, int col, double val)

{

this.row = row;

this.col = col;

this.val = val;

}

public Trituple(Trituple t, double val)

{

this(t.row, t.col, val);

}

public Trituple(Trituple t)

{

this(t.row, t.col, t.val);

}

public int compareTo(Trituple t)

{

if (row t.row)

{

return -1;

}

else

{

if (row == t.row)

{

if (col t.col)

{

return -1;

}

else

{

if (col == t.col)

{

return 0;

}

else

{

return 1;

}

}

}

else

{

return 1;

}

}

}

}

/**

*

*表示稀疏矩阵，rowNum行数，colNum列数，trituples三元组的顺序表

*add方法返回一个新的稀疏矩阵，check检查两个相加矩阵的规模是否相同

*

*/

class SparseMatrix

{

int rowNum;

int colNum;

ListTrituple trituples;

public SparseMatrix(ListTrituple list, int row, int col)

{

this.trituples = list;

this.rowNum = row;

this.colNum = col;

}

public SparseMatrix add(SparseMatrix matrix) throws IllegalArgumentException

{

if (check(matrix) == false)

{

throw new IllegalArgumentException("invalid matrix dimentions~");

}

ListTrituple list = new ArrayListTrituple();

int loop = trituples.size() + matrix.trituples.size();

int index = 0, index0 = 0;

while (loop 0)

{

Trituple t = trituples.get(index);

Trituple t0 = matrix.trituples.get(index0);

if (t.compareTo(t0) 0)

{

list.add(new Trituple(t));

index++;

loop--;

}

else

{

if (t.compareTo(t0) == 0)

{

list.add(new Trituple(t, t.val + t0.val));

index++;

index0++;

loop -= 2;

}

else

{

list.add(new Trituple(t0));

index0++;

loop--;

}

}

}

SparseMatrix sm = new SparseMatrix(list, rowNum, colNum);

return sm;

}

private boolean check(SparseMatrix matrix)

{

if (this.rowNum != matrix.rowNum || this.colNum != matrix.colNum)

{

return false;

}

return true;

}

}

Q2: java 加法运算器

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

public class Computer extends JFrame{

private Container contentPane = null;

private JPanel computerPanel = null;

private JPanel buttonPanel = null;

private JTextField sourceField1 = null;

private JTextField sourceField2 = null;

private JTextField resultField = null;

private JLabel addLabel = null;

private JLabel resultLabel = null;

private JButton submitButton = null;

private JButton resetButton = null;

public Computer(){

this.setSize(200,200);

this.setLocation(350,150);

this.init();

this.setVisible(true);

}

public void init(){

contentPane = this.getContentPanel();

contentPane.setLayout(new GridLayout(2,1));

computerPanel = new JPanel(new FlowLayout(20,20));

buttonPanel = new JPanel(new FlowLayout(50,25));

sourceField1 = new JTextField(5);

sourceField2 = new JTextField(5);

resultField = new JTextField(5);

resultField.setEnable(true);

addLabel = new JLabel("+",JLabel.CENTER);

resultLabel = new JLabel("=",JLabel.CENTER);

submitButton = new JButton("确定");

submitButton.addActionListener(new ActionListener(){

public void actionPerform(ActionEvent e){

try{

int source1 = Integer.parseInt(sourceField1.getText());

int source2 =Integer.parseInt(sourceField2.getText());

resultField.setText(String.valueOf(source1+source2));

}

catch(NumberFormatException e){

JOptionPane.showMessageDialog(null,"请先输入数字");

}

catch(NullPointException e){

JOptionPane.showMessageDialog(null,"输入为空");

}

}

});

resetButton = new JButton("取消");

resetButton.addActionListener(new ActionListener(){

public void actionPerform(ActionEvent e){

sourceField1.setText("");

sourceField2.setText("");

resultField.setText("");

}

});

computerPanel.add(sourceField1);

computerPanel.add(addLabel);

computerPanel.add(sourceField2);

computerPanel.add(resultLabel);

computerPanel.add(resultField);

buttonPanel.add(submitButton);

buttonPanel.add(resetButton);

contentPanel.add(computerPanel);

contentpanel.add(buttonPanel);

}

public static void main(String args[]){

Computer computer = new Computer();

}

}

有错误啊!! 因为没有编译器!! 有些字母拼写错java中运算器的代码了!

Q3: JAVA稀疏矩阵运算器

2 设计

2.1 用十字链表存储稀疏矩阵

为了能有效存储稀疏矩阵的元素， 本文采用十字链表对数据进行存储， 所设计的十字链表C++语言描述如下： Typedef struct OLNode{

Int　 i , j ;

ElemType e;

Struct OLNode * right, * down;

}OLNode; *OLink;

　

Typedef struct{

OLink * rhead, * chead;

　 Int　 mu,nu,tu;

}CrossList;

2.2 稀疏矩阵相乘主要算法设计

稀疏矩阵乘法运算器的设计主要设计到稀疏矩阵的创建和相乘运算， 下面给出这两个过程的C++语言描述为：

2.2.1 稀疏矩阵的创建 Statue CreateSMatrix_OL (CrossList M){

//创建稀疏矩阵M。

If (M)　 free(M);

Scanf (m,n,t);

M.mu:=m;　 M.nu:=n;　 M.tu:=t;

If　 (! ( M.rhead=(OLink * )malloc( (m+1) * sizeof(OLink) ) ) ) exit (OVERFLOW)

If　 (! ( M.chead=(OLink * )malloc( (n+1) * sizeof(OLink) ) ) ) exit (OVERFLOW)

M.rhead[　 ]+M.chead[　 ]=NULL;

For ( scanf( i, j, e); i!=0 ; scanf ( I, j, e ) ){

　 If(! ( p=(OLNode * )malloc( sizeof (OLNode) ) ) ) exit ( OVERFLOW )

　 P—i = i; p—j=j ; p—e=e;

　 If (M . rhead [ i ] = =NULL)　 M . rhead [ i ] = p;

　 Else{

For ( q = M . rhead [ i ]; ( q—right ) q— right— j j;　 q = q— right;)

p—right =q—right ;　 q—right=p;　 }

Q4: 用JAVA编一个计算器的程序,要里边的注释

package counter;

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

public class Counter implements ActionListener {

JFrame counter = null;

Container cou = null;

JTextField txt = null;

JPanel pan = null;

JButton [] btn = null;

JLabel lblbrand = null,lbltype = null;

String sign = "",sign1 = "0",sign2 = "",sign3 = "";

char operator = ' ', operator1 = '+';

int i = 0;

double resault = 0;

int b = 0;

public Counter() {

counter = new JFrame("计算器");

cou = counter.getContentPane();

cou.setLayout(null);

lblbrand = new JLabel("大象牌");

lblbrand.setForeground(Color.BLUE);

lblbrand.setBounds(15,8,70,20);

cou.add(lblbrand);

lbltype = new JLabel("x-14250");

lbltype.setForeground(Color.GREEN);

lbltype.setBounds(265,8,70,20);

cou.add(lbltype);

txt = new JTextField("0.");

txt.setCaretPosition(2);

txt.setHorizontalAlignment(JTextField.TRAILING);

cou.add(txt);

txt.setBounds(15,28,300,30);

pan = new JPanel(new GridLayout(5,4,10,10));

pan.setBounds(15,68,300,160);

btn = new JButton[20];

String [] btnname = {"Off","Back","C","Exit","7","8","9","+","4","5",

"6","-","1","2","3","*","0",".","=","/"};

for(int i = 0; i 20; i++)

{

btn[i] = new JButton(btnname[i]);

pan.add(btn[i]);

btn[i].addActionListener(this);

}

btn[7].setFont(new java.awt.Font("宋体", Font.PLAIN, 16));

btn[11].setFont(new java.awt.Font("宋体", Font.PLAIN, 16));

btn[15].setFont(new java.awt.Font("宋体", Font.PLAIN, 16));

btn[17].setFont(new java.awt.Font("宋体", Font.PLAIN, 16));

btn[18].setFont(new java.awt.Font("宋体", Font.PLAIN, 16));

btn[19].setFont(new java.awt.Font("宋体", Font.PLAIN, 16));

cou.add(pan);

counter.setSize(335,280);

counter.setVisible(true);

}

public void actionPerformed(ActionEvent e) {

operator = e.getActionCommand().charAt(0);

annal();

if(!sign.equals(""))

opinion(sign);

else

showresault(sign1);

if(i % 2 != 0)

txt.setText("");

}

private void annal(){

int l = 0;

switch (operator) {

case '1':

case '2':

case '3':

case '4':

case '5':

case '6':

case '7':

case '8':

case '9':

if (!sign.equals("0"))

sign = sign + Character.toString(operator);

else

sign = sign.concat(Character.toString(operator)).substring(1);

break;

case '0':

if (!sign.equals("") !sign.equals("0"))

sign = sign + Character.toString(operator);

else

sign = "0";

break;

case 'B':

if (sign.length() 1 sign.charAt(txt.getText().length() - 1) != '.') {

sign = (sign.substring(0,sign.length() - 1));

} else if (sign.length() 2) {

sign = (sign.substring(0,sign.length() - 2));

} else {

sign = "0";

}

break;

case 'C':

sign = "";

sign2 = "";

sign1 = "0";

operator = ' ';

break;

case 'E':

System.exit(0);

break;

case 'O':

sign = "";

sign2 = "";

sign1 = "0";

operator = ' ';

i++;

break;

case '+':

case '-':

case '*':

case '/':

count();

break;

case '=':

count();

operator1 = ' ';

sign3 = "-1";

break;

case '.':

if (sign.equals("")) {

sign = "0".concat(Character.toString(operator));

} else {

for (int i = 0; i sign.length(); i++) {

if (sign.charAt(i) == '.') {

l++;

}

}

if (l == 0) {

sign = sign + Character.toString(operator);

}

}

break;

}

}

private void count(){

double number1 = 0,number2 = 0;

if (!sign.equals(""))

sign2 = sign;

else

sign2 = "0";

sign = "";

if (!sign3.equals("-1"))

sign3 = sign1;

else

sign3 = "0";

number1 = Double.valueOf(sign3).doubleValue();

number2 = Double.valueOf(sign2).doubleValue();

switch(operator1){

case '+':

resault = number1 + number2;

break;

case '-':

resault = number1 - number2;

break;

case '*':

resault = number1 * number2;

break;

case '/':

resault = number1 / number2;

break;

case ' ':

resault = Double.valueOf(sign2).doubleValue();

}

operator1 = operator;

sign1 = Double.toString(resault);

}

private void showresault(String sign) {

int j = sign.length() - 1;

String subsign = "";

for (int i = 0; i = j; i++) {

if (sign.charAt(i) == '.')

{

j = i;

break;

}

}

if (j != sign.length() - 1) {

subsign = sign.substring(j+1);

if (Double.valueOf(subsign).doubleValue() 0)

txt.setText(sign);

else

txt.setText(sign.substring(0, j));

}

else

txt.setText(sign);

}

private void opinion(String sign){

txt.setText(sign);

}

public static void main(String[] args) {

Counter counter = new Counter();

}

}

这个是以前自己做的一个计算器,可能不是很完善,注释没写,但代码相对简单,应该可以看明白

Q5: 关于Java编程的习题，不会做求高人指导（应该只是入门课题，我才上大一）

package desc;

import java.util.List;

import java.util.ArrayList;

import java.util.Scanner;

/**

* 键盘输入两个数，求和

*

* 附赠：java程序 ：求给出的任意两数(a,b)之间的所有素数，输出结果每行按指定个数(c)输出

*

* 素数：指在一个大于1的自然数中，除了1和此整数自身外，没法被其他自然数整除的数。

*

* @author javaBrid

* @since 2011-10-14

*/

public class TestPrimeNumber {

/**

* 键盘输入两个数，求和

*/

public static int toAdd()

{

int sum = 0;

//控制台输入

Scanner sc = new Scanner(System.in);

//提示信息

String[] message = {"请输入第一个值(回车确定)：",

"请输入第二个值(回车确定)："};

//根据index选择message

int index = 0;

//保存输入的值

String str;

String str2;

//正则判断是否是数字,

String regex = "[+|-]?[0-9]+";

int a=0;

int b=0;

while(true)

{

if(index == 2)//两个数都输入后退出输入

{

break;

}

//提示信息

System.out.println(message[index]);

//获取输入值

str2 = str = sc.next();

//如果有"+"或"-"，去掉

str = (str.startsWith("+")||str.startsWith("-"))?str.substring(1):str;

//如果是数字

if(str.matches(regex))

{

switch(index)

{

case 0: //a的值

a = str2.startsWith("-")?(- Integer.parseInt(str)):Integer.parseInt(str);

index++;

break;

case 1: //b的值

b = str2.startsWith("-")?(- Integer.parseInt(str)):Integer.parseInt(str);

index++;

break;

default:;

}

}

else

{

System.out.println("输入错误：非数字【"+str+"】，请输入数字");

}

}

sum = a+b;

System.out.println("结果是：("+a+") + ("+b+") = " +sum);

return sum;

}

/**

* 求a和b之间的所有素数

* a b要求 a1b1 ab或ba

* @param a 起始点

* @param b 结束点

* @param c 每行的显示个数

*/

public static void showPrimeNumber(int a,int b,int c)

{

if(a1 b1 c0)

{

//保证list中的元素顺序

int index = 0;

//当i%j==0时，说明这个i不是素数flag = false

boolean flag;

//初始化数据

int m = Math.min(a, b);

int n = Math.max(a, b);

//保存m和n中的素数

List primes = new ArrayList();

for(int i=m;i=n;i++)

{

flag = true;

for(int j=2;ji;j++)

{

if(i%j == 0)

{

flag = false;

break;

}

}

//flag=true时,记录下这个素数

if(flag)

{

primes.add(index++, i);

}

}

//按要求输出结果

System.out.println(m+"和"+n+"之间的所有素数共有【"+primes.size()+"】个(每行显示"+c+"个)：");

for(int i=0;iprimes.size();i++)

{

//(i%c==0)?"\n":"") 控制换行,如果这一行是c或c的倍数则换行

System.out.print(((i%c==0 i0)?"\n":"") + primes.get(i)+(i==primes.size()-1?" \n\n":" "));

}

}

else

{

System.out.println("输入有误，检查a和b是否大于1,c是否大于0！");

}

}

/**

* 求a和b之间的所有素数

* a b要求 a1b1 ab或ba

* a,b,c用键盘输入

*

*/

public static void showPrimeAsYours()

{

//控制台输入

Scanner sc = new Scanner(System.in);

//提示信息

String[] message = {"请输入a的值(要求a1，回车确定)：",

"请输入b的值(要求b1，回车确定)：",

"请输入c的值(要求c0，回车确定)："};

//根据index选择message

int index = 0;

String str;

//正则判断是否是数字,

String regex = "[+]?[0-9]+";

int a=0;

int b=0;

int c=0;

while(true)

{

if(index == 3)

{

break;

}

//提示信息

System.out.println(message[index]);

//获取输入值

str = sc.next();

//如果有"+"号，去掉

str = str.startsWith("+")?str.substring(1):str;

//如果是数字

if(str.matches(regex))

{

switch(index)

{

case 0: //a的值

if(Integer.parseInt(str)1)//确保a1

{

a = Integer.parseInt(str);

index++;

}

else

{

System.out.println("a值输入错误：【"+str+"】，要求a1");

}

break;

case 1: //b的值

if(Integer.parseInt(str)1)//确保b1

{

b = Integer.parseInt(str);

index++;

}

else

{

System.out.println("b值输入错误：【"+str+"】，要求b1");

}

break;

case 2: //c的值

if(Integer.parseInt(str)0)//确保c0

{

c = Integer.parseInt(str);

index++;

}

else

{

System.out.println("c值输入错误：【"+str+"】，要求c1");

}

break;

default:;

}

}

else

{

switch(index)

{

case 0: //a输入错误

System.out.println("a值输入错误：【"+str+"】，要求a1");

break;

case 1: //b输入错误

System.out.println("b值输入错误：【"+str+"】，要求b1");

break;

case 2: //c输入错误

System.out.println("c值输入错误：【"+str+"】，要求c1");

break;

default:;

}

}

}

//输入完毕后，查找素数

TestPrimeNumber.showPrimeNumber(a, b, c);

}

/**

* @param args

*/

public static void main(String[] args)

{

//求输入的两个数字的和

TestPrimeNumber.toAdd();

//输出2和100间的所有素数,每行显示5个

//TestPrimeNumber.showPrimeNumber(2,100,5);

//使用键盘输入a,b,c

//TestPrimeNumber.showPrimeAsYours();

}

}

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