初学者：java练习题

2024-10-03 17:44:230 次浏览 投稿

程序代码：import java.awt.*;public class MenuExample extends Frame {MenuExample(String title) {super(title);//设置框架标题MenuBar mbar = _________________;//创建菜单条//创建菜单对象:文件,编辑,帮助Menu menuFile = new Menu("文件");Menu menuEdit = _________________;Menu menuHelp = _________________;//创建"文件"菜单的菜单项对象MenuItem menuItemFileNew=new MenuItem("新建");MenuItem menuItemFileOpen=_________________;MenuItem menuItemFileSave=new MenuItem("保存");MenuItem menuItemFileSaveAs=_________________;MenuItem menuItemFileQuit=new MenuItem("退出");//创建"编辑"菜单的菜单项对象MenuItem menuItemEditUndo=new MenuItem("撤消");MenuItem menuItemEditCut=_________________;MenuItem menuItemEditCopy=new MenuItem("复制");MenuItem menuItemEditPaste=_________________;//创建"帮助"菜单的菜单项对象MenuItem menuItemHelp=new MenuItem("关于...");//将菜单项添加到对应的菜单中menuFile.add(menuItemFileNew);__________________________________;__________________________________;menuFile.add(menuItemFileSaveAs);__________________________________;//在菜单中增加一条分隔线menuFile.add(menuItemFileQuit);menuEdit.add(menuItemEditUndo);menuEdit.addSeparator();//在菜单中增加一条分隔线__________________________________;menuEdit.add(menuItemEditCopy);menuEdit.add(menuItemEditPaste);menuHelp.add(menuItemHelp);//将菜单添加到菜单条中mbar.add(menuFile);_________________;_________________;//将菜单条加入到框架_________________;}public static void main(String args[]) {MenuExample menu = new MenuExample("简单文本编辑器");menu.pack();menu.setSize(300, 200);menu.setVisible(true);}}

答案为

import java.awt.*;public class MenuExample extends Frame {MenuExample(String title) {super(title);//设置框架标题MenuBar mbar = new MenuBar();//创建菜单条//创建菜单对象:文件,编辑,帮助Menu menuFile = new Menu("文件");Menu menuEdit = new Menu("编辑");Menu menuHelp = new Menu("帮助");//创建"文件"菜单的菜单项对象MenuItem menuItemFileNew=new MenuItem("新建");MenuItem menuItemFileOpen=new MenuItem("打开");MenuItem menuItemFileSave=new MenuItem("保存");MenuItem menuItemFileSaveAs=new MenuItem("另存为");MenuItem menuItemFileQuit=new MenuItem("退出");//创建"编辑"菜单的菜单项对象MenuItem menuItemEditUndo=new MenuItem("撤消");MenuItem menuItemEditCut=new MenuItem("剪切");;MenuItem menuItemEditCopy=new MenuItem("复制");MenuItem menuItemEditPaste=new MenuItem("粘贴");//创建"帮助"菜单的菜单项对象MenuItem menuItemHelp=new MenuItem("关于...");//将菜单项添加到对应的菜单中menuFile.add(menuItemFileNew);menuFile.add(menuItemFileOpen);menuFile.add(menuItemFileSave);menuFile.add(menuItemFileSaveAs);menuEdit.addSeparator();;//在菜单中增加一条分隔线menuFile.add(menuItemFileQuit);menuEdit.add(menuItemEditUndo);menuEdit.addSeparator();//在菜单中增加一条分隔线menuEdit.add(menuItemEditCut);menuEdit.add(menuItemEditCopy);menuEdit.add(menuItemEditPaste);menuHelp.add(menuItemHelp);//将菜单添加到菜单条中mbar.add(menuFile);mbar.add(menuEdit);mbar.add(menuHelp);//将菜单条加入到框架this.setMenuBar(mbar);}public static void main(String args[]) {MenuExample menu = new MenuExample("简单文本编辑器");menu.pack();menu.setSize(300, 200);menu.setVisible(true);}}

运行结果为 答案为

import java.awt.*;public class MenuExample extends Frame {MenuExample(String title) {super(title);//设置框架标题MenuBar mbar = new MenuBar(); //_________________;//创建菜单条//创建菜单对象:编辑 ,查看，帮助Menu menuFile = new Menu("编辑");Menu menuEdit = new Menu("查看");Menu menuHelp = new Menu("帮助");//创建"编辑"菜单的菜单项对象MenuItem fuzhi=new MenuItem("复制");MenuItem zhantie=new MenuItem("粘贴");//创建"查看"菜单的菜单项对象MenuItem biaozhun=new MenuItem("标准型");MenuItem kexue=new MenuItem("科学型");MenuItem fenzhu=new MenuItem("数字分组");//创建"帮助"菜单的菜单项对象MenuItem bangzhu=new MenuItem("帮助主题");MenuItem guanyu=new MenuItem("关于计算机");//将菜单项添加到对应的菜单中menuFile.add(fuzhi);menuFile.add(zhantie);menuEdit.add(biaozhun);menuEdit.add(kexue);menuEdit.addSeparator();//在菜单中增加一条分隔线menuEdit.add(fenzhu);menuHelp.add(bangzhu);menuHelp.addSeparator();//在菜单中增加一条分隔线menuHelp.add(guanyu);//将菜单添加到菜单条中mbar.add(menuFile);mbar.add(menuEdit);//_________________;mbar.add(menuHelp);//_________________;//将菜单条加入到框架this.setMenuBar(mbar);//_________________;}public static void main(String[] args) {MenuExample menuExample = new MenuExample("简单文本编辑器");menuExample.pack();menuExample.setSize(300, 200);menuExample.setLocationByPlatform(true);menuExample.setVisible(true);}}

运行结果为 3、运行下列程序，并回答有关问题：

import java.awt.*;public class LayoutDemo extends Frame {private String name[] = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9",".", "+", "-", "*", "/", "=" };private Button button[] = new Button[name.length];public LayoutDemo() {setTitle("布局管理器");setLayout(new FlowLayout());for (int i = 0; i