正文
java键盘代码大全 java中键盘输入语句
小程序：扫一扫查出行【扫一扫了解最新限行尾号】
复制小程序
求Java编程代码
//学生类
public class Student {
private String school;
private String id;
int[] score = new int[3];
private int sum;
private int ava;
public int getSum() {
return sum;
}
public void setSum(int sum) {
this.sum = sum;
}
public int getAva() {
return ava;
}
public void setAva(int ava) {
this.ava = ava;
}
public String getSchool() {
return school;
}
public void setSchool(String school) {
this.school = school;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public Student(){}
public Student(String school,String id,int[] score){
this.id = id;
this.school = school;
this.score = score;
}
public int sum(){
sum = 0;
for(int i = 0; i score.length;i++){
sum += score[i];
}
return sum;
}
public int ava(){
ava = sum/3;
return ava;
}
public String introduce(){
return "我就读的学校是："+ school +",学号："+ id + ",语数外总分："+ sum + ",语数外平均分：" + ava ;
}
}
//测试类
import java.util.Scanner;
public class TestStudent {
public static void main(String[] args) {
//数组存放从控制台输入的学生信息进行封装
Student[] stu = new Student[5];
//声明从控制台获取输入
Scanner sc = new Scanner(System.in);
System.out.println("请输入学生信息：");
for(int i = 0;i stu.length;i++){
Student s = new Student();
if(sc.hasNextLine()){
s.setSchool(sc.next());
s.setId(sc.next());
s.score[0] = sc.nextInt();
s.score[1] = sc.nextInt();
s.score[2] = sc.nextInt();
}
stu[i] = s;
s.setSum(s.sum());
s.setAva(s.ava());
}
//按总分排序
for(int i = 0; i stu.length; i++){
for(int j = i+1;j stu.length; j++){
Student temp;
if(stu[i].sum() stu[j].sum()){
temp = stu[i];
stu[i] = stu[j];
stu[j] = temp;
}
}
}
//利用introduce方法打印排序后的学生信息
for(Student student: stu){
System.out.println(student.introduce());
}
}
}
求JAVA用Eclipse写个的计算器实现键盘功能代码。
以前写的，自己改下吧
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class CalculatorJFrame extends JFrame implements ActionListener
{
private boolean clickBeforeOperator; //点击"+,-,*,/"等数学运算符和清除回车时 clickBeforeOperator = true
private int firstInputChar; //判断是否是第一次输入字符,firstInputChar = 0时是第一次输入
private double answer; //文本框中结果
private int Operator;
private DisplayPanel displaypanel = new DisplayPanel();
private ButtonPanel buttonpanel = new ButtonPanel();
private class DisplayPanel extends JPanel
{
private JTextField text;
public DisplayPanel()
{
text = new JTextField("",30);
text.setBackground(Color.white); //设置文本颜色
text.setHorizontalAlignment(JTextField.RIGHT); //设置右对齐
text.setEditable(false); //设置不可编辑
this.setLayout(new BorderLayout()); //面板设置为边布局
this.add(text,BorderLayout.CENTER); //text文本行放在面板DisplayPanel
}
}
public class ButtonPanel extends JPanel
{
private String button_str[] = { "7","8","9","sqrt","sin","Clear","退格","*", //字符串数组
"4","5","6",".","cos","倒数","/","-", //做JButton的标签
"1","2","3","0","tan","n!","=","+" } ;
private JButton button[] = new JButton[button_str.length]; //创建JButton按钮
public ButtonPanel()
{
this.setLayout(new GridLayout(3,8,5,5)); //面板布局管理器设置为网格布局管理器
this.setBackground(Color.pink);
for(int i = 0; i button_str.length; i++)
{
button[i] = new JButton(button_str[i]);
this.add(button[i]); //在面板上添加button组件
}
//设置button颜色
for(int a1 = 0; a1 = 2; a1++){
button[a1].setBackground(Color.yellow); //设置数字7~9的颜色
}
button[3].setBackground(Color.green);
button[4].setBackground(Color.green);
button[5].setBackground(Color.ORANGE);
button[6].setBackground(Color.ORANGE);
// button[7].setBackground(Color.magenta);
for(int b1 = 8; b1 = 11; b1++){
button[b1].setBackground(Color.yellow); //设置数字4~5的颜色
}
button[12].setBackground(Color.green);
button[13].setBackground(Color.green);
// button[14].setBackground(Color.magenta);
// button[15].setBackground(Color.magenta);
for(int c1 = 16; c1 = 19; c1++){
button[c1].setBackground(Color.yellow); //设置数字1~3的颜色
}
button[20].setBackground(Color.green);
button[21].setBackground(Color.green);
// button[22].setBackground(Color.magenta);
// button[23].setBackground(Color.magenta);
}
}
public CalculatorJFrame(){ //构造方法
super("颜氏计算器3代");
answer = 0;
clickBeforeOperator = false; //指示器
firstInputChar = 0;
Operator = -1;
Dimension dim = getToolkit().getScreenSize();
this.setBounds(dim.width/8, dim.height/8, dim.width/2, dim.height/2); //窗口居中
this.setBackground(Color.LIGHT_GRAY);
//this.setResizable(false);
this.setDefaultCloseOperation(EXIT_ON_CLOSE); //(水平间距hgap = 0,垂直间距vgap =10)
this.getContentPane().setLayout(new BorderLayout(0,10)); // 框架默认变布局管理器，可省略
this.getContentPane().add(displaypanel,"North"); //框架"北"放置文本行text
this.getContentPane().add(buttonpanel,"Center"); //框架"中"放置面板组件
for(int i = 0; i buttonpanel.button_str.length; i++)
{
buttonpanel.button[i].addActionListener(this);
}
// this.pack();
this.setVisible(true);
}
public void actionPerformed(ActionEvent e){
String button_label = e.getActionCommand();
//******************************输入double型数据********************************
if((button_label.charAt(0) = '0' button_label.charAt(0) = '9') || button_label == "."){
if(clickBeforeOperator == true || firstInputChar == 0){ //如果点击了运算符，清除回车等按键，再点击数字键
displaypanel.text.setText("" + button_label);
clickBeforeOperator = false;
firstInputChar = 1;
}
else{
if(!(button_label == ".")) //如果输入数字
{
displaypanel.text.setText(displaypanel.text.getText()+button_label);
}
if(button_label == "."){ //如果输入点
boolean isContainerPoint = false; //判断逻辑量
if(displaypanel.text.getText().equals("")) //如果文本行中字符串为空
{
isContainerPoint = true;
displaypanel.text.setText("0.");
}
for(int i = 0; i displaypanel.text.getText().length(); i++) //判断文本行中字符串是否已含小数点
{
if(displaypanel.text.getText().charAt(i) == '.'){
isContainerPoint =true;
}
}
if(isContainerPoint == false)
{
displaypanel.text.setText(displaypanel.text.getText() + ".");
}
}
}
}
//******************************开根号运算*************************************
try{
if(button_label == "sqrt" ){
if(displaypanel.text.getText().charAt(0) == '-')
{
// displaypanel.text.setText("负数不能开根号");
JOptionPane.showMessageDialog(this, "负数不能开根号");
}
else{
clickBeforeOperator = true;
firstInputChar = 0;
double sqrtX = Math.sqrt(Double.parseDouble(displaypanel.text.getText()));
displaypanel.text.setText(""+sqrtX);
}
}
}
catch(StringIndexOutOfBoundsException sioobe)
{
JOptionPane.showMessageDialog(this, "已空，无法进行开根号操作");
}
finally
{
}
//*******************************三角函数运算**************************************
try{
if(button_label == "sin"){
clickBeforeOperator = true;
firstInputChar = 0;
double sinX = Math.sin(Double.parseDouble(displaypanel.text.getText()));
displaypanel.text.setText(""+sinX);
}
if(button_label == "cos"){
clickBeforeOperator = true;
firstInputChar = 0;
double cosX = Math.cos(Double.parseDouble(displaypanel.text.getText()));
displaypanel.text.setText(""+cosX);
}
if(button_label == "tan"){
clickBeforeOperator = true;
firstInputChar = 0;
double tanX = Math.tan(Double.parseDouble(displaypanel.text.getText()));
displaypanel.text.setText(""+tanX);
}
//***********************************求倒数******************************************
if(button_label == "倒数"){
if(Double.parseDouble(displaypanel.text.getText()) == 0)
{
// displaypanel.text.setText("零没有倒数");
JOptionPane.showMessageDialog(this, "零没有倒数");
}
else
{
clickBeforeOperator = true;
firstInputChar = 0;
double daoshuX = 1.0/(Double.parseDouble(displaypanel.text.getText()));
displaypanel.text.setText(""+daoshuX);
}
}
//************************************求阶乘**************************************
if(button_label == "n!"){
int i = Integer.parseInt(displaypanel.text.getText());
int sum = 1;
for(int k = 1; k= i; k++)
sum *= k;
displaypanel.text.setText(""+sum);
clickBeforeOperator = true;
firstInputChar = 0;
}
}
catch(NumberFormatException nfe)
{
JOptionPane.showMessageDialog(this, "已空，无法进行相应操作");
}
finally
{
}
//**************************************清除键*************************************
if(button_label == "Clear"){
displaypanel.text.setText("");
clickBeforeOperator = true;
firstInputChar = 0;
213 }
//**************************************回车键*************************************
try //异常处理
{
if(button_label == "退格"){
String str = displaypanel.text.getText();
displaypanel.text.setText(str.substring(0,str.length()-1)); //最初此语句无效？？？？why，当把回车键标签名设置为BackSpace时，此语句失效
clickBeforeOperator = true;
firstInputChar = 0; //BackSpace字符串长度过长,导致界面上无法显示全部字符串，故无法实现此功能
// if(displaypanel.text.getText() == "")
// throw new Exception("NullException");
}
}
catch(StringIndexOutOfBoundsException sioobe)
{
JOptionPane.showMessageDialog(this, "已空，无法继续删除");
}
// catch(Exception ex)
// {
// if(ex.getMessage() == "NullException")
// JOptionPane.showMessageDialog(this, "已空，无法继续删除");
// }
finally
{
}
/* for(int i = 0; i str.length() - 1; i++){
char a = str.charAt(i);
text.setText(text.getText() + a);
} */
//***************************************加减乘除运算*****************************************
if(button_label == "+" || button_label == "-" || button_label == "*" || button_label =="/")
{
if(button_label == "+"){
clickBeforeOperator = true;
firstInputChar = 0;
answer = Double.parseDouble(displaypanel.text.getText());
Operator = 0;
}
if(button_label == "-"){
clickBeforeOperator = true;
firstInputChar = 0;
answer = Double.parseDouble(displaypanel.text.getText());
Operator = 1;
}
if(button_label == "*"){
clickBeforeOperator = true;
firstInputChar = 0;
answer = Double.parseDouble(displaypanel.text.getText());
Operator = 2;
}
if(button_label == "/"){
clickBeforeOperator = true;
firstInputChar = 0;
answer = Double.parseDouble(displaypanel.text.getText());
Operator = 3;
}
}
if(button_label == "="){
switch(Operator)
{
case 0:
answer += Double.parseDouble(displaypanel.text.getText());
displaypanel.text.setText(""+answer);
firstInputChar = 0;
break;
case 1:
answer -= Double.parseDouble(displaypanel.text.getText());
displaypanel.text.setText(""+answer);
firstInputChar = 0;
break;
case 2:
answer *= Double.parseDouble(displaypanel.text.getText());
displaypanel.text.setText(""+answer);
288 firstInputChar = 0;
break;
case 3:
if(Double.parseDouble(displaypanel.text.getText()) == 0){
// displaypanel.text.setText("除数不能为零");
JOptionPane.showMessageDialog(this, "除数不能为零");
}
else
{
answer /= Double.parseDouble(displaypanel.text.getText());
displaypanel.text.setText(""+answer);
firstInputChar = 0;
}
break;
}
}
}
public static void main(String args[]){
new CalculatorJFrame();
}
}
java script键盘上的按键所对应的代码是什么？
如下所示：
script
function keyDown() {
var value= event.keyCode
var key = String.fromCharCode(event.keyCode)
alert " 键: " + key + "值: " + value )
}
document.onkeydown = keyDown
/script
js跳转页面方法：
1.按钮式:
INPUT name="pclog" type="button" value="GO" onClick="location.href='website'"
2.链接式:
a href="javascript:history.go(-1)"返回上一步/a
a href="%=Request.ServerVariables("HTTP_REFERER")%"返回上一步/a
3.直接跳转式:
scriptwindow.location.href='website';/script
在java中用键盘输入数据的代码是什么？
1.根据你输出的语句java键盘代码大全：首行为文件名java键盘代码大全，"+"其余内容为文件内容java键盘代码大全，以空行结尾。按Ctrl+c组合键结束输入"，你是想按Ctrl+c就退出程序结束输入，但是你的程序并没有定义当按下Ctrl+c键的响应。所以你一直输入内容是没办法结束程序的。你只有手动停止编译器停止程序。
2.你没有指定fileName文件的类型，也没生成位置，那么在你对应的工程路径下生成一个缺省的文件，名字为你第一次输入的fileName，内容为第二次输入的内容，你可以用记事本打开，看到输入的内容。
程序没有错，只是没有完成你想要的功能而已！
java 键盘输入语句怎么写
第一种：
public class ShuRu{
public static void main(String arg[]){
System.out.println(arg[1]);
}
}
第二种：
import java.util.Scanner;
public class ShuRu{
public static void main(String arg[]){
Scanner in=new Scanner(System.in);
String str=in.next();
System.out.println(str);
}
}
直接输入 a,b
输出为 a,bstem.in.read();
扩展资料：
有输入就有输出，输出语句为
Java中的输出语句有以下四种：
1、System.out.println(1111);//换行打印
2、System.out.print(1111);//不换行打印
3、System.out.write(2222);//字节输出
4、System.out.printf("%+8.3f\n", 3.14);//按格式输出
注：
System.out.println(); 是最常用的输出语句，它会把括号里的内容转换成字符串输出到输出窗口（控制台），并且换行，当输出的是一个基本数据类型时，会自动转换成字符串，如果输出的是一个对象，会自动调用对象的toString();方法，将返回值输出到控制台
System.out.print(); 与第一个很相似，区别就是上一个输出后会换行，而这个命令输出后并不换行。
System.out.printf(); 这个方法延续了C语言的输出方式，通过格式化文本和参数列表输出。
求一个java 计算器，支持键盘输入的代码，最好有注释
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
public class Test {
public static void main(String[] args) {
//while(true){
Scanner sc = new Scanner(System.in);
System.out.println(jisuan(sc.next()));
}
private static float jisuan(String cont){
List arryList = new ArrayList();
char[] str = cont.toCharArray();
Character astr;
String s = "";
for(int i=0;istr.length;i++){
astr = str[i];
if(astr=='+'||astr=='-'||astr=='*'||astr=='/'||astr=='=')
{
arryList.add(s);
s="";
if(astr!='='){
arryList.add(astr.toString());
}
}else{
s += astr;
}
}
float count = 0;
List jjlist = chengchuModel(arryList);
String ssf = "";
String var1 = "";
String var2 = "";
if(jjlist.size()=3){
for(int i=1;ijjlist.size();i=i+2){ //jjlist中就只有加减法了
ssf = (String)jjlist.get(i); // 获得jjlist中的加法或减法字符进行判断
var2 = (String)jjlist.get(i+1);
if(i==1){ //判断第一个运算符是加号还是减号java键盘代码大全，两个情况下的运行也是不同的
var1 = (String)jjlist.get(i-1); //只有第一次加减的时候才会去取前一个数字进行运算
if(ssf.trim().equals("-")){
count = Float.parseFloat(var1) - Float.parseFloat(var2);
}else{
count = Float.parseFloat(var1) + Float.parseFloat(var2);
}
}else{
if(ssf.trim().equals("-")){
count = count - Float.parseFloat(var2);
}else{
count = count + Float.parseFloat(var2);
}
}
}
}else{
count = Float.parseFloat(jjlist.get(0).toString());
}
return count;
}
private static boolean checkstr(String str){
if(!str.trim().equals("*")!str.trim().equals("/"))
return true;
return false;
}
private static boolean cheng(String str){
if(str.trim().equals("*"))
return true;
return false;
}
private static boolean chu(String str){
if(str.trim().equals("/"))
return true;
return false;
}
private static List chengchuModel(List list){ //将输入的算术的所有乘除法算出来只剩下加减法
String var1 ="";
String var2 ="";
String var3 ="";
for(int i=1;ilist.size();i=i+2){
var1 = (String)list.get(i-1);
var2 = (String)list.get(i);
var3 = (String)list.get(i+1);
if(!checkstr(var2)){
if(cheng(var2)){
list.set(i-1, String.valueOf((Float.parseFloat(var1)*Float.parseFloat(var3))));
list.remove(i);
list.remove(i);
i = i-2;
//
}else if(chu(var2)){
list.set(i-1, String.valueOf((Float.parseFloat(var1)/Float.parseFloat(var3))));
list.remove(i);
list.remove(i);
i = i-2;
}
}
}
return list;
}
}
测试java键盘代码大全：
输入：33-6*5+7/4=
结果：4.75
关于java键盘代码大全和java中键盘输入语句的介绍到此就结束了，不知道你从中找到你需要的信息了吗 ？如果你还想了解更多这方面的信息，记得收藏关注本站。
