本文目录一览：
- 1、java小白，自学中，我做了一道基础的java练习题，不知道正确与否，视频教学中并没有给出解答，求大神检查
- 2、JAVA作业
- 3、谁能帮一下我，java选修课的作业，一题两题都可以，先谢谢了！！
- 4、Java作业求帮助 题一: 编写一个Java程序，在程序中定义一个PersonA类，定义
- 5、请帮我做一道JAVA的作业题，很简单的，我是初学者
- 6、一个java的作业！~
java小白，自学中，我做了一道基础的java练习题，不知道正确与否，视频教学中并没有给出解答，求大神检查
看来你没有运行过啊！！！
main方法写错了，参数丢了
scanner没有实例化，就是没有new
scanner方法错了，in.nextInt（）；
if判断‘=’是赋值，‘==’才是判断是否相等，另外不能连等
a==b b==c 应该这样；
逻辑到是没错的，这样可以实现；如果嵌套的话，可能是让你将判断是否大于1000 写在
else{
if（sum1000）{
}else{
}
}里面
JAVA作业
4 final
5 方法名称、返回值、参数签名
6 public class C extends B implements C
7 class
8 false，true，false
9 private
10 Object
11 编译时类型与运行时类型不一致，重写，重载
12 import
13 抽象方法，final修饰或者private修饰
14 aceg
判断：
1 不一定 protect修饰的 父类与子类在不同包里不能继承
2 错
3 错
4 对
5 错
6 对
更多JAVA问题，请去ITMUCH，IT木虫
谁能帮一下我，java选修课的作业，一题两题都可以，先谢谢了！！
2、类的方法与异常处理：
在一个类的main方法中定义一个长度为8的int型数组，用for循环对数组中的元素1到8的值。随机产生两个整数，将这两个整数作为数组的下标来引用数组中的元素，求出这两个元素的积，并在屏幕上输出这两个元素的值和积。要求在出现数组下标越界时，采用try-catch的方法捕获异常。
import java.util.Random;
public class SecondTest {
public static void main(String[] args) {
//定义一个长度为8的int型数组
int[] ary = {35, 42, 13, 46, 59, 37, 125, 99};
//用for循环对数组中的元素1到8的值
for(int i= 1; i ary.length;i++){
System.out.print(ary[i] + "t");
}
System.out.println();
try{
Random rand = new Random();
//随机产生两个整数
int first = rand.nextInt();
int second = rand.nextInt();
//这两个整数作为数组的下标来引用数组中的元素，求出这两个元素的积
long mul = ary[first] * ary[second];
//屏幕上输出这两个元素的值和积
System.out.println("积为" + mul);
}catch(ArrayIndexOutOfBoundsException exp){
//出现数组下标越界时，采用try-catch的方法捕获异常
System.out.println("数组下标越界! Error!");
}
}
}
、类与对象的基础题：
1）编程实现：设计一个类Simple，有三个成员变量，分别为int型、double型和String型，这三个成员变量分别含有各自的get方法和set方法，可以用toString方法显示这三个成员变量。，
2）声明测试类：在测试类的main 方法中创建Simple类的对象aSimple,此对象调用set方法分别对对象的各个属性设置具体的值，然后调用get方法将aSimple的具体的值输出在屏幕上。
public class TestSimple {//测试类的
public static void main(String[] args) {
//创建Simple类的对象aSimple
Simple aSimple = new Simple();
//set方法分别对对象的各个属性设置具体的值
aSimple.setIntValue(5);
aSimple.setDoubleValue(123.45D);
aSimple.setStrValue("string value for simple");
//get方法将aSimple的具体的值输出在屏幕上
System.out.println("int value for simple is: " + aSimple.getIntValue());
System.out.println("double value for simple is: " + aSimple.getDoubleValue());
System.out.println("String value for simple is: " + aSimple.getStrValue());
}
}
class Simple{//类Simple
private int intValue;//int型成员变量
private double doubleValue;//double型成员变量
private String strValue;//String型成员变量
//用toString方法显示这三个成员变量
public String toString(){
return intValue + ", " + doubleValue + ", " + strValue;
}
public double getDoubleValue() {
return doubleValue;
}
public void setDoubleValue(double doubleValue) {
this.doubleValue = doubleValue;
}
public int getIntValue() {
return intValue;
}
public void setIntValue(int intValue) {
this.intValue = intValue;
}
public String getStrValue() {
return strValue;
}
public void setStrValue(String strValue) {
this.strValue = strValue;
}
}
Java作业求帮助 题一: 编写一个Java程序，在程序中定义一个PersonA类，定义
代码1：extends PersonA
代码2：s1.setName("张三");
代码3：s1.setDepartment("计算机系");
代码4：System.out.println(s1.getName());
代码5：System.out.println(s1.getDepartment());
注意，后四句最后的分号别落下了
请帮我做一道JAVA的作业题，很简单的，我是初学者
package jisuanqi;
import java.awt.BorderLayout;
import java.awt.Dimension;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JButton;
import javax.swing.BorderFactory;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JTextField;
import javax.swing.*;
/**
* pTitle: /p
*
* pDescription: /p
*
* pCopyright: Copyright (c) 2007/p
*
* pCompany: /p
*
* @author not attributable
* @version 1.0
*/
public class Jisuan extends JFrame {
JPanel contentPane;
JButton btnmultiply = new JButton();
JButton btn3 = new JButton();
JButton btndivide = new JButton();
JButton btn2 = new JButton();
JButton btn5 = new JButton();
JButton btn0 = new JButton();
JButton btnclear = new JButton();
JButton btnequal = new JButton();
JButton btn1 = new JButton();
JButton btn6 = new JButton();
JButton bntplus = new JButton();
JButton btnminus = new JButton();
JButton btn4 = new JButton();
JButton btn9 = new JButton();
JButton btn8 = new JButton();
JButton btn7 = new JButton();
JPanel jPanel1 = new JPanel();
JTextField txt = new JTextField();
boolean flag=false;
String operand1;
String operand2;
double result;
String action;
public Jisuan() {
try {
setDefaultCloseOperation(EXIT_ON_CLOSE);
jbInit();
} catch (Exception exception) {
exception.printStackTrace();
}
}
/**
* Component initialization.
*
* @throws java.lang.Exception
*/
private void jbInit() throws Exception {
contentPane = (JPanel) getContentPane();
contentPane.setLayout(null);
setSize(new Dimension(300, 400));
setTitle("Frame Title");
btnmultiply.setBounds(new Rectangle(227, 322, 42, 35));
btnmultiply.setText("+");
btnmultiply.addActionListener(new Jisuan_jButton1_actionAdapter(this));
contentPane.setBorder(BorderFactory.createEtchedBorder());
contentPane.setToolTipText("");
btn3.setBounds(new Rectangle(160, 263, 42, 35));
btn3.setText("3");
btn3.addActionListener(new Jisuan_btn3_actionAdapter(this));
btndivide.setBounds(new Rectangle(227, 263, 42, 35));
btndivide.setText("-");
btndivide.addActionListener(new Jisuan_jButton3_actionAdapter(this));
btn2.setBounds(new Rectangle(93, 263, 42, 35));
btn2.setText("2");
btn2.addActionListener(new Jisuan_btn2_actionAdapter(this));
btn5.setBounds(new Rectangle(93, 201, 42, 35));
btn5.setText("5");
btn5.addActionListener(new Jisuan_btn5_actionAdapter(this));
btn0.setBounds(new Rectangle(25, 322, 42, 35));
btn0.setText("0");
btn0.addActionListener(new Jisuan_btn0_actionAdapter(this));
btnclear.setBounds(new Rectangle(93, 322, 42, 35));
btnclear.setText("c");
btnclear.addActionListener(new Jisuan_jButton7_actionAdapter(this));
btnequal.setBounds(new Rectangle(160, 322, 42, 35));
btnequal.setText("=");
btnequal.addActionListener(new Jisuan_btnequal_actionAdapter(this));
btn1.setBounds(new Rectangle(25, 263, 42, 35));
btn1.setText("1");
btn1.addActionListener(new Jisuan_btn1_actionAdapter(this));
btn6.setBounds(new Rectangle(160, 201, 42, 35));
btn6.setText("6");
btn6.addActionListener(new Jisuan_btn6_actionAdapter(this));
bntplus.setBounds(new Rectangle(227, 201, 42, 35));
bntplus.setText("*");
bntplus.addActionListener(new Jisuan_btnminus_actionAdapter(this));
btnminus.setBounds(new Rectangle(227, 137, 42, 35));
btnminus.setText("/");
btnminus.addActionListener(new Jisuan_bntplus_actionAdapter(this));
btn4.setBounds(new Rectangle(25, 201, 42, 35));
btn4.setText("4");
btn4.addActionListener(new Jisuan_btn4_actionAdapter(this));
btn9.setBounds(new Rectangle(160, 137, 42, 35));
btn9.setText("9");
btn9.addActionListener(new Jisuan_btn9_actionAdapter(this));
btn8.setBounds(new Rectangle(93, 137, 42, 35));
btn8.setText("8");
btn8.addActionListener(new Jisuan_btn8_actionAdapter(this));
btn7.setBounds(new Rectangle(25, 137, 42, 35));
btn7.setText("7");
btn7.addActionListener(new Jisuan_btn7_actionAdapter(this));
jPanel1.setBorder(BorderFactory.createEtchedBorder());
jPanel1.setBounds(new Rectangle(13, 128, 270, 244));
txt.setHorizontalAlignment(SwingConstants.RIGHT);
txt.setBounds(new Rectangle(13, 61, 270, 46));
contentPane.add(btndivide);
contentPane.add(btn3);
contentPane.add(btn2);
contentPane.add(btnclear);
contentPane.add(btnmultiply, null);
contentPane.add(btnequal);
contentPane.add(btn1);
contentPane.add(btn0);
contentPane.add(btn5);
contentPane.add(btn6);
contentPane.add(bntplus);
contentPane.add(btn4);
contentPane.add(btn7);
contentPane.add(btn8);
contentPane.add(btn9);
contentPane.add(btnminus);
contentPane.add(jPanel1);
contentPane.add(txt);
}
public void jButton1_actionPerformed(ActionEvent e) {
action="plus";
operand1=txt.getText();
txt.setText("");
flag=true;
}
public void jButton3_actionPerformed(ActionEvent e) {
action="minus";
operand1=txt.getText();
txt.setText("");
flag=true;
}
public void btn1_actionPerformed(ActionEvent e) {
if(flag){
txt.setText(btn1.getActionCommand());
flag=false;
}
else{
txt.setText(txt.getText()+btn1.getActionCommand());
}
}
public void btn6_actionPerformed(ActionEvent e) {
if(flag){
txt.setText(btn6.getActionCommand());
flag=false;
}
else{
txt.setText(txt.getText()+btn6.getActionCommand());
}
}
public void btn2_actionPerformed(ActionEvent e) {
if(flag){
txt.setText(btn2.getActionCommand());
flag=false;
}
else{
txt.setText(txt.getText()+btn2.getActionCommand());
}
}
public void btn3_actionPerformed(ActionEvent e) {
if(flag){
txt.setText(btn3.getActionCommand());
flag=false;
}
else{
txt.setText(txt.getText()+btn3.getActionCommand());
}
}
public void btn4_actionPerformed(ActionEvent e) {
if(flag){
txt.setText(btn4.getActionCommand());
flag=false;
}
else{
txt.setText(txt.getText()+btn4.getActionCommand());
}
}
public void btn5_actionPerformed(ActionEvent e) {
if(flag){
txt.setText(btn5.getActionCommand());
flag=false;
}
else{
txt.setText(txt.getText()+btn5.getActionCommand());
}
}
public void btn7_actionPerformed(ActionEvent e) {
if(flag){
txt.setText(btn7.getActionCommand());
flag=false;
}
else{
txt.setText(txt.getText()+btn7.getActionCommand());
}
}
public void btn8_actionPerformed(ActionEvent e) {
if(flag){
txt.setText(btn8.getActionCommand());
flag=false;
}
else{
txt.setText(txt.getText()+btn8.getActionCommand());
}
}
public void btn9_actionPerformed(ActionEvent e) {
if(flag){
txt.setText(btn9.getActionCommand());
flag=false;
}
else{
txt.setText(txt.getText()+btn9.getActionCommand());
}
}
public void btn0_actionPerformed(ActionEvent e) {
if(flag){
txt.setText(btn0.getActionCommand());
flag=false;
}
else{
txt.setText(txt.getText()+btn0.getActionCommand());
}
}
public void jButton7_actionPerformed(ActionEvent e) {
txt.setText("");
}
public void bntplus_actionPerformed(ActionEvent e) {
/*
operand1=Integer.parseInt(txt.getText());
action="plus";
flag=true;
*/
action="divide";
operand1=txt.getText();
txt.setText("");
flag=true;
}
public void btnminus_actionPerformed(ActionEvent e) {
action="multiply";
operand1=txt.getText();
txt.setText("");
flag=true;
}
public void btnequal_actionPerformed(ActionEvent e) {
double digit1;
double digit2;
operand2=txt.getText();
if(flag==false){
if(action.equals("divide")){
digit1=Integer.parseInt(operand1);
digit2=Integer.parseInt(operand2);
result=digit1 / digit2;
txt.setText(new Double(result).toString());
flag=true;
}else if(action.equals("plus")){
digit1=Integer.parseInt(operand1);
digit2=Integer.parseInt(operand2);
result=digit1 + digit2;
txt.setText(""+(int)result);
flag=true;
}else if(action.equals("multiply")){
digit1=Integer.parseInt(operand1);
digit2=Integer.parseInt(operand2);
result=digit1 * digit2;
txt.setText(""+(int)result);
flag=true;
}else if(action.equals("minus")){
digit1=Integer.parseInt(operand1);
digit2=Integer.parseInt(operand2);
result=digit1-digit2;
txt.setText(""+(int)result);
flag=true;
}
}
}
}
class Jisuan_btnminus_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_btnminus_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.btnminus_actionPerformed(e);
}
}
class Jisuan_bntplus_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_bntplus_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.bntplus_actionPerformed(e);
}
}
class Jisuan_jButton7_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_jButton7_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.jButton7_actionPerformed(e);
}
}
class Jisuan_btn0_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_btn0_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.btn0_actionPerformed(e);
}
}
class Jisuan_btn9_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_btn9_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.btn9_actionPerformed(e);
}
}
class Jisuan_btn8_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_btn8_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.btn8_actionPerformed(e);
}
}
class Jisuan_btn7_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_btn7_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.btn7_actionPerformed(e);
}
}
class Jisuan_btn6_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_btn6_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.btn6_actionPerformed(e);
}
}
class Jisuan_btn5_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_btn5_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.btn5_actionPerformed(e);
}
}
class Jisuan_btn4_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_btn4_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.btn4_actionPerformed(e);
}
}
class Jisuan_btn3_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_btn3_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.btn3_actionPerformed(e);
}
}
class Jisuan_btn2_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_btn2_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.btn2_actionPerformed(e);
}
}
class Jisuan_btn1_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_btn1_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.btn1_actionPerformed(e);
}
}
class Jisuan_jButton3_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_jButton3_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.jButton3_actionPerformed(e);
}
}
class Jisuan_jButton1_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_jButton1_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.jButton1_actionPerformed(e);
}
}
class Jisuan_btnequal_actionAdapter implements ActionListener {
private Jisuan adaptee;
Jisuan_btnequal_actionAdapter(Jisuan adaptee) {
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e) {
adaptee.btnequal_actionPerformed(e);
}
}
这个是实现的方法，按钮的名字不一定一样，最主要是这个要一样 action="minus";
一点都不简单 很长啊
一个java的作业！~
import java.lang.Math;
//a+bx+cx^2=y
public class func(double a1,double b1,double c1,double x1){
double a=a1;idouble b=b1;double c=c1;double x=x1;idouble y=0;
public void function(double a,double b,double x)
{
if((b^2-4*a*c)0.0)
printf("没有实根");
double x1=-(b/2a)+Math.sqrt(b^2-4*a*c)/2a;
double x2=-(b/2a)-Math.sqrt(b^2-4*a*c)/2a;
printf("根为x1=%d,x2=%d",x1,x2);
}