注意:请勿改动main()主方法和其他已有语句内容,仅在下划线处填入适当的语句。
程序运行结果如下:
9173546280
public class ex20_2 {
private int[] a=new int[10];
public static void main(String[] args)
ex20_2 obj20_2=new ex20_2 );
obj20_2. method ();
}
public void init () {
for(int i=0;i<a.length;i++) {
a[i] =i;
}
}
public void method() {
int c,i,j;
i=0;
j=a.length-1;
init();
while(i<j){
while((a[i]%2==1)&&i<j)
i++;
while((a[j]%2==0)&&i<j)
j--
if(i<j){
c=a [i];
______________;
a[j]=c;
_______________;
}
}
for(i=0;i<a.length;i++){
System.out.print(Integer.toString(a[i]));
}
}
}
第3题
个文本框,选中文本域中部分文字后,单击按钮“复制”,所选文字将显示在文本框中。 import java.applet.Applet; import java.awt.*; import java.awt.event.*; public class java3 extends Applet implements ActionL- istener { TextArea ta=new TextArea(5,30); TextField tf=new TextField(30); Button button=new Button("复制"); String text="AWT提供基本的GUl组件,\n"+" 具有可以扩展的超类,\n"+"它们的属性是继承的。\ n": public void init { setLayout(new FlowLayout(FlowLayout.left)); ta.setText(text); ta.setEditable(true); add(ta); add(button); add(tf); ta.addActionListener(this); } public void actionPerformed(ActionEvent e) { String S; s=ta.getSelectText; if(e.getSource= =button) tf.setText(s); } }
第4题
ng[]args){ int sum=add(10): System.out.println("1+2+…+9+10="+ sum); } public static int add( ){ if(n= =l){ ; } else ; } }
第5题
如果一个工人可管理多个设备,而一个设备只被一个工人管理,则实体“工人”与实体“设备”之间存在【 】联系。
第6题
下面是关于字符界面基本输入输出的程序,请在程序的每条横线处填写一个语句,使程序的功能完整。
注意:请勿改动main()主方法和其他已有的语句内容,仅在横线处填入适当的语句。
______________________
public class SimpleCharInOut{
public static void main(String args[]){
char c=" ";
System.out.println("Enter a character please: ");
try{
____________________//接受用户键盘输入的字符并保存在变量c中
}
catch(________________________e){}
System.out.println("You've entered character "+c);
}
}
第7题
听力原文:ct_ctjbm_blankf_05755(20092)
将代数式[*]转换成程序设计中的表达式为【 】。
第8题
果将鼠标置于小矩形上,则鼠标光标状态改为小十字,按下鼠标左键可拖曳,双击鼠标左键(或右键)时,小矩形消失。 import java.awt.*; import java.awt.event.*; import java.util.*; import java.awt.geom.*; import javax.swing.*; public class java3 { public static void main(String[]args) { MouseFrame. frame=new MouseFrame: frame.setDefaultCloseOperation(JFrame.EXIT_ oN_CLOSE); frame.show; } } class MouseFrame. extends JFrame { public MouseFrame { setTitle("java3"); setSize(DEFAULT WIDTH, DEFAULT HEIGHT): MousePanel panel=new MousePanel; Container contentPane=getContentPane; contentPane.add(panel); } public static final int DEFAULT_WIDTH=300; public static final int DEFAULT_HEIGHT=200; } class MousePanel extends JPanel { public MousePanel { squares=new ArrayList; current=null: addMouseListener(new MouseHandler); addMouseMotionListener(new MouseMotionHan- dler); } public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2=(Graphics2D)g; for(int i=0;i<squares.size;i++) g2.draw((Rectangle2D)squares.get(i)); } public void find(Point2D p) { for(int i=0;i<squares.size;i++) { Rectangle2D r=(Rectangle2D)squares.get(i); if(r.contains(p))return r; } return null: } public void add(Point2D p) { double x=P.getX; double Y=P.getY: current=new Rectangle2D.Double( x-SIDELENGTH/2. y-SlDELENGTH/2. S1DELENGTH, SIDELENGTH); squares.add(current); repaint; } public void remove(Rectangle2D s) { if(S= =null)return: if(S= =current)current=null; squares.remove(s): repaint; } private static final int SIDELENGTH=10: private ArrayList squares; private Rectangle2D current; private class MouseHandter extends MouseAction- Listener { public void mousePressed(MouseEvent event) { current=find(event.getPoint); if(current= =null) add(event.getPoint); } public void mouseClicked(MouseEvent event) { current=find(event.getPoint); if(current!=nullevent.getClickCount >=2) remove(current); } } private class MouseMotionHandler implements Mouse- MotionListener { public void mouseMoved(MouseEvent event) { if(find(event.getPoint)= =null) setCursor(Cursor.getDefaultCursor); else setCursor(Cursor.getPredefinedCursor (Cursor.CROSSHAIR_CURSOR)); } public void mouseDragged(MouseEvent event) { if(current!=null) { int x=event.getX: int Y=event.getY; 、 current.setFrame( x-SIDELENGTH/2, Y-SlDELENGTH/2. SIDELENGTH, SIDELENGTH); repaint; } } } }
第9题
static void main(String[]args){ InputStreamReader ir; BufferedReader in; ir=new InputStreamReader(System.in); in=new BufferedReader(ir); int year=1900; System.out.print("请输入年份:"); try{ String s=in.readLine; ; } (Exception e){ } if( ) System.OUt.println(year+"是闰年"); else System.out.println(year+"不是闰年"); } }
第10题
单击各个选项的文字标签后,所选中的选项将为当前选项。“系统”选项上有3个复选按钮,分别控制“声卡”、“显卡”和“网卡”三个选项,选中某个按钮后,它所指示的选项就可用,否则不可用。 import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.*; public class java3 extends JFrame{ JTabbedPane config=new JTabbedPane: public java3{ super("java3"); setSize(500,300); setDefaultCloseoperation(EXIT_ON_CLOSE); JPanel configPane=new JPanel; configPane.setLayout(new BoxLayout(config- Pane,BoxLayout.Y_AXIS)); JTextArea question=new JTextArea("下面的哪 个选项\n"+"你想设置?"); question.setEditable(false); question.setMaximumSize(new Dimension(300, 50)); question.setAlignmentX(0.Of); question.setBackground(configPane.getBack- ground); JCheckBox audioCB=new JCheckBox ("声卡", true); JCheckBox nicCB=new JCheckBox("网卡", true); JCheckBox tvCB=new JCheckBox("显示卡", false); configPane.add(Box.createVerticalGlue); configPane.add(question); configPane.add(audioCB); configPane.add(nicCB); configPane.add(tvCB); configPane.add(Box.ereateVerticalGlue); JLabel audioPane=new JLabel("声卡页面"); JLabel niePane=new JLabel("网卡页面"); JLabel tvPane=new JLabel("显示卡页面"); JLabel helpPane=new JLabel("帮助信息"); audioCB.addItemListener(new TabManager(au- dioPane)); nicCB.addItemListener(new TabManager (nicPane)); tvCB.addItemListener(new TabManager (tvPane)): config.addTab("系统",null,configPane," Choose Installed Options”); config.addTab("声卡",null,audioPane,"Audio system configuration”); config.addTab("网卡",null,nicPane;"Netwot- king configuration"); config.addTab("显示卡",null,tvPane,"Video system configuration"); config.addTab("帮助",null,helpPane,"How Do I…"); getContentPane.add(config,BorderLayout. CENTER); } class TabManger implements ActionListener{ Component tab; public TabManager(Component tabToManage){ tab=tabToManage; } public void ItemStateChanged(ItemEvent ie){ int index=config.indexOfComponent(tab); if(index!=-l){ config.setEnabledAt(index,ie.getStateChange = =ItemEvent.SELECTED); } this.repaint; } } public static void main(String args[]){ java3 SC=new java3; se.setVisible(true); } }
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