1．A，B，D
2． Love:Game
3．13
abc夏日
4．13579
5．9javaHello
6．
public class Xiti6?{
??public static void main (String args[ ]) {
???????String s1,s2,s3,t1="ABCDabcd";
???????System.out.println("字符串原來是這個樣子: "+t1);
???????s1=t1.toUpperCase();
???????System.out.println("字符串中的小寫字母變成大寫是這個樣子: "+s1);
???????s2=t1.toLowerCase();
???????System.out.println("字符串中的大寫字母變成小寫是這個樣子: "+s2);
???????s3=s1.concat(s2);
???????System.out.println("大寫字符串連接小寫字符串是這個樣子: "+s3);
??????}
??????
???}
7．
class Xiti7?
{ public static void main(String args[ ])
??{ String ?s ="中華人民共和國";
????char a=s.charAt(0);
????char b=s.charAt(6);
????System.out.println("第一個字符: ?"+a);
????System.out.println("最后一個字符: ?"+b);
??}
}
8．
import java.util.*;
class Xiti8
{ ?public static void main(String args[]){
?????int year,month;
?????System.out.println("請輸入年份和月份，每輸入一個數(shù)回車確認(rèn)");
?????Scanner reader=new Scanner(System.in);
?????year= reader.nextInt();
?????month= reader.nextInt();
??????String [] day=new String[42];
??????System.out.println(" 日 ?一 ?二 ?三 ?四 ?五 ?六");
???????Calendar rili=Calendar.getInstance();
???????rili.set(year,month-1,1);//將日歷翻到year年month月1日,注意0表示一月...11表示十二月
???????int 星期幾=rili.get(Calendar.DAY_OF_WEEK)-1;
???????int dayAmount=0;
???????if(month==1||month==3||month==5||month==7||month==8||month==10||month==12)
??????????dayAmount=31;
???????if(month==4||month==6||month==9||month==11)
??????????dayAmount=30;
???????if(month==2)
???????????if(((year%4==0)&&(year%100!=0))||(year%400==0))
??????????????dayAmount=29;
???????????else
??????????????dayAmount=28;
???????for(int i=0;i<星期幾;i++)
????????????day[i]="";
???????for(int i=星期幾,n=1;i<星期幾+dayAmount;i++){
????????????if(n<=9)
?????????????????day[i]=String.valueOf(n)+" " ;
????????????else
?????????????????day[i]=String.valueOf(n);
????????????n++;
???????} ?
???????for(int i=星期幾+dayAmount;i<42;i++)
????????????day[i]="";
???????for(int i=0;i<星期幾;i++)
?????????????{ ?day[i]="**";
?????????????}
???????for(int i=0;i<day.length;i++) ??
????????{ if(i%7==0)
??????????{ ?System.out.println("");
??????????}
???????System.out.print(" ?"+day[i]);
?????????
??????}
????}
}
9．
import java.util.*;
class Xiti9
{ ?public static void main(String args[]){
?????int year1,month1,day1,year2,month2,day2;
?????Scanner reader=new Scanner(System.in);
?????System.out.println("請輸入第一個日期的年份 月份 日期 ，每輸入一個數(shù)回車確認(rèn)");
?????year1= reader.nextInt();
?????month1= reader.nextInt();
?????day1= reader.nextInt();
?????System.out.println("請輸入第二個日期的年份 月份 日期 ，每輸入一個數(shù)回車確認(rèn)");
?????year2= reader.nextInt();
?????month2= reader.nextInt();
?????day2= reader.nextInt();
??????Calendar calendar=Calendar.getInstance();
??????calendar.set(year1,month1,day1); ?
??????long timeYear1=calendar.getTimeInMillis();
??????calendar.set(year2,month2,day2); ?
??????long timeYear2=calendar.getTimeInMillis();
??????long 相隔天數(shù)=Math.abs((timeYear1-timeYear2)/(1000*60*60*24));
??????System.out.println(""+year1+"年"+month1+"月"+day1+"日和"+
????????????????????????????year2+"年"+month2+"月"+day2+"日相隔"+相隔天數(shù)+"天");
???} ?
}
10．
public class Xiti10
{ ?public static void main(String args[])
???{ ?double a=0,b=0,c=0;
??????a=12;
??????b=24;
??????c=Math.max(a,b);
??????System.out.println(c);
??????c=Math.min(a,b);
??????System.out.println(c);
?????c=Math.pow(2,3);
??????System.out.println(c);
??????c=Math.abs(-0.123);
??????System.out.println(c);
??????c=Math.asin(0.56);
??????System.out.println(c);
??????c=Math.cos(3.14);
??????System.out.println(c);
??????c=Math.exp(1);
??????System.out.println(c);
??????c=Math.log(8);
??????System.out.println(c);
???}
}
1．BorderLayout布局。
2．不可以。
3．A,C。
4．
import java.util.StringTokenizer;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Xiti4
{ ?public static void main(String args[])
???{ ComputerFrame fr=new ComputerFrame();
?????fr.setTitle("計算的窗口");
???}
}
class ComputerFrame extends JFrame implements TextListener
{ ??TextArea text1,text2;
????int count=1;
????double sum=0,aver=0;
??public ComputerFrame()
??{ setLayout(new FlowLayout());
??????text1=new TextArea(6,20);
??????text2=new TextArea(6,20);
??????add(text1);
??????add(text2);
??????text2.setEditable(false);
??????text1.addTextListener(this);
??????setSize(300,320);
??????setVisible(true);
??????addWindowListener(new WindowAdapter()
????????????{ ?public void windowClosing(WindowEvent e)
???????????????{ ?System.exit(0);
???????????????}
????????????});
??????validate();
?}
?public void textValueChanged(TextEvent e)
?{ ?String s=text1.getText();
??????sum=0;
??????aver=0; ?
??????StringTokenizer fenxi=new StringTokenizer(s," ,'\n'");
?????int n=fenxi.countTokens();
?????count=n;
?????double a[]=new double[n];
?????for(int i=0;i<=n-1;i++)
?????{ ?String temp=fenxi.nextToken(); ?
????????try { a[i]=Double.parseDouble(temp);
?????????????sum=sum+a[i];
???????????}
????????catch(Exception ee)
???????????{ count--;
???????????}
?????}
?????aver=sum/count;
?????text2.setText(null);
?????text2.append("\n和:"+sum);
?????text2.append("\n平均值:"+aver);
???}
}
5．
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class Xiti5
{ ?public static void main(String args[])
???{ ComputerFrame fr=new ComputerFrame();
?????fr.setTitle("計算");
???}
}
class ComputerFrame extends Frame implements ActionListener
{ TextField text1,text2,text3;
??Button button1,button2,button3,button4;
??Label label;
??public ComputerFrame()
??{setLayout(new FlowLayout());
???text1=new TextField(10);
???text2=new TextField(10);
???text3=new TextField(10);
???label=new Label(" ",Label.CENTER);
???label.setBackground(Color.green);
???add(text1);
???add(label);
???add(text2);
???add(text3);
???button1=new Button("加"); ???
???button2=new Button("減");
???button3=new Button("乘");
???button4=new Button("除");
???add(button1);
???add(button2);
???add(button3);
???add(button4);
???button1.addActionListener(this);
???button2.addActionListener(this);
???button3.addActionListener(this); ?
???button4.addActionListener(this);
???setSize(300,320);
???setVisible(true);
???addWindowListener(new WindowAdapter()
????????????{ ?public void windowClosing(WindowEvent e)
???????????????{ ?System.exit(0);
???????????????}
????????????});
???validate();
??} ??
??public void actionPerformed(ActionEvent e)
??{ double n;
????if(e.getSource()==button1)
????{ ?double n1,n2; ?
???????try{ n1=Double.parseDouble(text1.getText());
????????????n2=Double.parseDouble(text2.getText());
????????????n=n1+n2;
????????????text3.setText(String.valueOf(n));
????????????label.setText("+");
??????????}
???????catch(NumberFormatException ee)
??????????{ text3.setText("請輸入數(shù)字字符");
??????????}
?????}
????else if(e.getSource()==button2)
????{ ?double n1,n2; ?
???????try{??n1=Double.parseDouble(text1.getText());
????????????n2=Double.parseDouble(text2.getText());
????????????n=n1-n2;
????????????text3.setText(String.valueOf(n));
????????????label.setText("-");
??????????}
???????catch(NumberFormatException ee)
??????????{ text3.setText("請輸入數(shù)字字符");
??????????}
?????}
?????else if(e.getSource()==button3)
??????{double n1,n2; ?
???????try{ n1=Double.parseDouble(text1.getText());
????????????n2=Double.parseDouble(text2.getText());
????????????n=n1*n2;
????????????text3.setText(String.valueOf(n));
????????????label.setText("*");
??????????}
???????catch(NumberFormatException ee)
??????????{ text3.setText("請輸入數(shù)字字符");
??????????}
??????}
??????else if(e.getSource()==button4)
??????{double n1,n2; ?
???????try{ n1=Double.parseDouble(text1.getText());
????????????n2=Double.parseDouble(text2.getText());
????????????n=n1/n2;
????????????text3.setText(String.valueOf(n));
????????????label.setText("/");
??????????}
???????catch(NumberFormatException ee)
??????????{ text3.setText("請輸入數(shù)字字符");
??????????}
??????}
?????validate();
??}
}
6．
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Xiti6
{ ??public static void main(String args[])
????{ ?new WindowPanel();
????}
}
class Mypanel extends JPanel implements ActionListener
{ ?Button button; ??
???TextField text;
???Mypanel() ?
???{ ?button=new Button(" ");
??????text=new TextField(12);
??????add(button);
??????add(text);
??????button.addActionListener(this);
???}
???public void actionPerformed(ActionEvent e)
???{ ?String name=text.getText();
??????if(name.length()>0)
????????button.setLabel(name);
??????validate();
???}
}
class WindowPanel extends Frame
{ ??Mypanel panel1,panel2;
????WindowPanel()
????{ panel1=new Mypanel();
??????panel2=new Mypanel();
??????panel1.setBackground(Color.red);
??????panel2.setBackground(Color.blue);
??????add(panel1,BorderLayout.SOUTH);
??????add(panel2,BorderLayout.NORTH);
??????setSize(300,320);
??????setVisible(true);
??????addWindowListener(new WindowAdapter()
????????????{ ?public void windowClosing(WindowEvent e)
???????????????{ ?System.exit(0);
???????????????}
????????????});
??????validate();
????}
}
7．參見10.13, 參照本章例子10.21。
8．
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Xiti8
{ public static void main(String args[])
???{ ??MoveFrame f=new MoveFrame();
???????f.setBounds(12,12,300,300);
???????f.setVisible(true);
???????f.setTitle("移動"); ?
???????f.validate();
???????f. addWindowListener(new WindowAdapter() ???
??????????????????????{ ??public void windowClosing(WindowEvent e)
???????????????????????????{ ?System.exit(0);
???????????????????????????}
??????????????????????}
???????????????????);
????}
}
class MoveFrame extends JFrame implements ActionListener
{ ?JButton controlButton,movedButton; ??
???public MoveFrame()
???{ ?controlButton=new JButton("單擊我運動另一個按鈕");
??????controlButton.addActionListener(this);
??????movedButton=new JButton();
??????movedButton.setBackground(new Color(12,200,34));
??????setLayout(null);
??????add(controlButton);
??????add(movedButton);
??????controlButton.setBounds(10,30,130,30);
??????movedButton.setBounds(100,100,10,10);
???}
??public void actionPerformed(ActionEvent e)
???{ ?int x=movedButton.getBounds().x;
??????int y=movedButton.getBounds().y;
??????x=x+5;
??????y=y+1;
??????movedButton.setLocation(x,y);
??????if(x>200)
??????{ x=100;
????????y=100;
??????}
???}
}
?
9．
import java.awt.*;
import java.awt.event.*;
public class Xiti9
{ ?public static void main(String args[])
????{ ?Win win=new Win();
????}
}
class Win extends Frame implements KeyListener
{ ??Button b[]=new Button[8];
????int x,y;
????Win()
????{ setLayout(new FlowLayout());
??????for(int i=0;i<8;i++)
?????????{ ?b[i]=new Button(""+i);
????????????b[i].addKeyListener(this);
????????????add(b[i]);
?????????}
??????addWindowListener(new WindowAdapter() { ??
??????????????????????????public void windowClosing(WindowEvent e){
?????????????????????????????System.exit(0);
???????????????????????????}
???????????????????????});
??????setBounds(10,10,300,300);
??????setVisible(true);
??????validate();
????}
public void keyPressed(KeyEvent e)
{ ????int moveDistance=1;
??????Component com=(Component)e.getSource();
??????int x=(int)com.getBounds().x;
??????int y=(int)com.getBounds().y;
??????Component component[]=this.getComponents();
??????if(e.getKeyCode()==KeyEvent.VK_UP)
????????{ ?y=y-moveDistance;
???????????com.setLocation(x,y);
???????????Rectangle comRect=com.getBounds();
???????????for(int k=0;k<component.length;k++)
???????????{ ?Rectangle orthRect=component[k].getBounds();
??????????????if(comRect.intersects(orthRect)&&com!=component[k])
??????????????{ ?y=y+moveDistance;
?????????????????com.setLocation(x,y);
?????????????????break;
??????????????}
???????????}
??????????if(y<=0) y=10;
????????}
??????else if(e.getKeyCode()==KeyEvent.VK_DOWN)
???????{ ??y=y+moveDistance;
???????????com.setLocation(x,y);
???????????Rectangle comRect=com.getBounds();
???????????for(int k=0;k<component.length;k++)
???????????{ ?Rectangle orthRect=component[k].getBounds();
??????????????if(comRect.intersects(orthRect)&&com!=component[k])
??????????????{ ?y=y-moveDistance;
?????????????????com.setLocation(x,y);
?????????????????break;
??????????????}
???????????}
??????????if(y>=300) y=300;
????????}
??????else if(e.getKeyCode()==KeyEvent.VK_LEFT)
????????{ ?x=x-moveDistance;
???????????com.setLocation(x,y);
???????????Rectangle comRect=com.getBounds();
???????????for(int k=0;k<component.length;k++)
???????????{ ?Rectangle orthRect=component[k].getBounds();
??????????????if(comRect.intersects(orthRect)&&com!=component[k])
??????????????{ ?x=x+moveDistance;
?????????????????com.setLocation(x,y);
?????????????????break;
??????????????}
???????????}
??????????if(x<=0) x=0;
????????}
??????else if(e.getKeyCode()==KeyEvent.VK_RIGHT)
????????{ ?x=x+moveDistance;
???????????com.setLocation(x,y);
???????????Rectangle comRect=com.getBounds();
???????????for(int k=0;k<component.length;k++)
???????????{ ?Rectangle orthRect=component[k].getBounds();
??????????????if(comRect.intersects(orthRect)&&com!=component[k])
??????????????{ ?x=x-moveDistance;
?????????????????com.setLocation(x,y);
?????????????????break;
??????????????}
???????????}
??????????if(x>=300) x=300;
????????}
????}
????public void keyTyped(KeyEvent e) {}
????public void keyReleased(KeyEvent e) {}
}?
