Java程序设计习题集

System.out.println(\}

}

四、写出下列程序完成的功能

1． public class Sum

{ public static void main( String args[ ]) { double sum = 0.0 ;

for ( int i = 1 ; i <= 100 ; i + + ) sum += 1.0/(double) i ;

System.out.println( \ }

}

答： sum=5.18737517639621

2．import java.io.* ;

public class Reverse

{ public static void main(String args[ ]) { int i , n =10 ;

int a[ ] = new int[10]; for ( i = 0 ; i < n ; i ++ ) try {

BufferedReader br = new BufferedReader( new InputStreamReader(System.in));

a[i] = Integer.parseInt(br.readLine( )); // 输入一个整数

} catch ( IOException e ) { } ; for ( i = n－1 ; i >= 0 ; i ―― ) System.out.print(a[i]+\ System.out.println( ); } } 答：

3．import java.awt.*;

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Java程序设计习题集

public class abc

{ public static void main(String args[]) { new FrameOut(); } }

class FrameOut extends Frame // Frame为系统定 { Button btn; // 义的窗框类

FrameOut( )

{ super(\按钮\

btn = new Button(\按下我\ setLayout(new FlowLayout( )); add(btn);

setSize(300,200); show( ); } }

答：

4． import java.io.*; public class Class1 {

public static void main(String args[ ]){ int i , Max , Min ; int a[ ] = { 12,67,8,98,23,56,124,55,99,100 }; Max = Min = a[0];

for ( i = 1 ; i < a.length; i ++ ) { if ( a[i]

if ( a[i]>Max ) Max = a[i]; }

System.out.println( Max+\

System.out.println( ); } }

答：

5． public class ABC

{

public static void main(String args[ ]){ int i , j ;

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Java程序设计习题集

int a[ ] = { 12,67,8,98,23,56,124,55,99,100 }; for ( i = 0 ; i < a.length-1; i ++ ) {

int k = i;

for ( j = i ; j < a.length ; j++ )

if ( a[j]

a[k] = temp; }

for ( i =0 ; i

System.out.print(a[i]+\ System.out.println( ); } }

答

6．import java.io.*;

public class Class1 {

public static void main( String args[] ) {

Fact N = new Fact( 4 ); System.out.println( N.fact( ) ); } }

class Fact { int n ;

Fact( int nn ) { n = nn; } int fact( ) { }

答：

7．import java.awt.*; import java.applet.Applet;

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int i , f = 1;

for ( i=1; i<=n; i++ )

f = f*i;

return f; }

Java程序设计习题集

public class DrawMyImage extends Applet { }

Image myImage; // 定义一个图像类Image的对象myImage public void init( ) { }

myImage = getImage(getDocumentBase( ),\

public void paint(Graphics g) { }

g.drawImage(myImage,0,0,this);

答：

8． import java.io.*; public class Class1 {

public static void main( String args[ ] ) { SubClass a = new SubClass( 10,3 ); System.out.println( a.exp( )); } }

class SuperClass { float x; int n;

SuperClass( float xx , int nn ) { x = xx ; n = nn; } }

class SubClass extends SuperClass {

SubClass( float xx , int nn ) { super( xx , nn ); } float exp( ) { } }

答：

9． import java.awt.*; import java.applet.Applet;

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float s = 1;

for ( int i = 1; i<=n; i++ ) s = s*x; return s;