有一篇作业java基础的（java课后作业）

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);

}