java程序题.docx

1、java程序题.1. /计算两个整数的乘法import javax.swing.JOptionPane;public class Java_1 public static void main( String args ) int x, y, result; String xVal, yVal; xVal = JOptionPane.showInputDialog( 输入第1个整数: ); yVal = JOptionPane.showInputDialog( 输入第2个整数: ); /*Fill*/ x = Integer.parseInt( _xVal_ ); y = Integer.par

2、seInt( yVal ); result = x * y; /*Fill*/ JOptionPane.showMessageDialog( null, 两个数的积: + result ); System.exit( 0 ); 2. import java.io.*;public class Java_1 public static void main(String args) int anArray; /声明一个整数型数组 anArray = new int10; /创建一个整数数组对象s /对数组中每个元素赋值并显示 for (int i = 0; i anArray.length; i+

3、) anArrayi = i; /*Fill*/ System.out.print(_anArrayi_+ ); System.out.println(); 3. class Variable int x=0,y=0,z=0;/类变量 /*Fill*/ void _init_(int x,int y) this.x=x; this.y=y; int z=5; /局部变量 System.out.println(*在初始化中*); System.out.println(x = +x+ y = +y+ z =+z); public class Java_1 public static void ma

4、in (String args) /*Fill*/ Variable v = new _Variable_(); System.out.println(*在初始化之前*); System.out.println(x = +v.x+ y = +v.y+ z =+v.z); /*Fill*/ v.init(20,_30_); System.out.println(*在初始化之后*); System.out.println(x = +v.x+ y = +v.y+ z =+v.z); 4. import javax.swing.*;public class Java_1 public static v

5、oid main( String args ) String strings = started, starting, ended, ending ; String output = ; /*Fill*/ for ( int i = 0; i strings._length_; i+ ) /*Fill*/ if ( strings i .endsWith( _ed_ ) ) output += + strings i + 结束于 edn; JOptionPane.showMessageDialog( null, output,显示字符串类的比较, JOptionPane.INFORMATION

6、_MESSAGE ); System.exit( 0 ); 5. import java.io.*;public class Java_1 public static void main(String args) /*FILL*/ _long_ s; /*FILL*/ _s = 1;_ for ( int i = 1; i b ) /*FILL*/ _m = b ;_ if ( m c ) /*FILL*/ _m = c ;_ System.out.println( min = + m); 7.import java.util.Random;public class Java_2 public

7、 static void main(String args) Random random = new Random(); float x = random.nextFloat();/产生0.0与1.0之间的一个符点数 int n = Math.round(20*x); /构造20以内的一个整数 long f = 1 ; /保存阶乘的结果 int k = 1 ; /循环变量 /*Fill*/ do_f*=k_; k+; /*Fill*/ _while(k=n);_ System.out.println(n+!= +f); 8. import java.io.*;public class Java

8、_2 public static void main(String args) int a = new int55; int i,j,k=1; for(i=0;i5;i+) /*Fill*/ for( j=0; _j5_ ;j+ ) if(i+j)4) aij=0; else /*Fill*/ _aij=k+_; for(i=0;i5;i+) for(j=0;j5;j+) if(aij10) System.out.print(aij+ ); else System.out.print(aij+ ); System.out.println(); 9. public class Java_2 pu

9、blic static void main( String args) int i,j,k; int a = new int2; /*Fill*/ int b_=1,2,3,4,1,2,3,4,1,2,3,4; /*Fill*/ int c= new _int 24_; a0 = new int3; a1 = new int3; for (i=0; i2;i+) for (j=0;j3;j+) aij=(i+1)*(j+2); for (i=0; i2;i+) for (j=0;j4;j+) cij=0; for (k=0; k3; k+) /*Fill*/ cij+=_ aik*bkj_;

10、/ Print Matix C for (i =0; i2; i+) /*Fill*/ for(j=0; _j4_; j+) System.out.print(cij+ ); System.out.println(); 10.public class Java_2 public static void main(String args) int arrayOfInts = 32, 87, 3, 589, 12, 1076, 2000, 8, 622, 127 ; int searchfor = 12; int i = 0; boolean foundIt = false; /*Fill*/ f

11、or ( ; i _arrayOfInts.length_; i+) if (arrayOfIntsi = searchfor) /*Fill*/ foundIt = _true_; break; /*Fill*/ if (_foundIt_) System.out.println(Found + searchfor + at index + i); else System.out.println(searchfor + not in the array); 11.public class Java_2 public int x,y; public Java_2() public Java_2

12、(int x,int y) this.x=x;this.y=y; /*FILL*/ public Java_2(_Java_2_ p) x=p.x;y=p.y; public Java_2 getLocation() Java_2 p=new Java_2(x,y); return p; public int getX() return x; public int getY() return y; public void move(int x,int y) this.x=x; this.y=y; public void setLocation(Java_2 p) x=p.x; y=p.y; p

13、ublic String toString() return(+Integer.toString(x)+,+Integer.toString(y)+); public void translate(int x,int y) this.x+=x; this.y+=y; public static void main(String args)/*FILL*/ Java_2 p=new _Java_2_(5,5); System.out.println(x=+p.x+ y=+p.y);/*FILL*/ System.out.println(点的坐标是+_p.toString_(); p.transl

14、ate(3,4); System.out.println(x=+p.x+ y=+p.y);/*FILL*/ System.out.println(点的坐标是+_p.toString_(); 12.import java.text.*;public class Java_2 public static void main(String args) Person people = new Person2; people0 = new Worker(老张, 30000); people1 = new Student(小王, 计算机科学); for (int i = 0; i people.lengt

15、h; i+) Person p = peoplei; /*FILL*/ System.out.println(_p.getName_() + , + p.getDescription(); /*FILL*/_abstract_ class Person public Person(String n) name = n; /*FILL*/ public _abstract_ String getDescription(); public String getName() return name; private String name;/*FILL*/class Worker _extends_

16、 Person public Worker(String n, double s) super(n); salary = s; public String getDescription() NumberFormat formatter = NumberFormat.getCurrencyInstance(); return 工人，年薪是 + formatter.format(salary) + 。; private double salary;/*FILL*/class Student _extends_ Person public Student(String n, String m) su

17、per(n); major = m; public String getDescription() return 学生，专业是 + major + 。; private String major;13. /DoubleArray.javaimport java.awt.*;import javax.swing.*;public class Java_3 extends JApplet int grades = 77, 68, 86, 73 , 96, 87, 89, 81 , 70, 90, 86, 81 ; int students, exams; String output; JTextA

18、rea outputArea; /对实例变量初始化 public void init() students = grades.length; exams = grades 0 .length; /*FILL*/ outputArea = new _JTextArea_(); Container c = getContentPane(); c.add( outputArea ); /输出 output = 数组是:; buildString(); output += nn最低分: + minimum() + n最高分: + maximum() + n; for ( int i = 0; i st

19、udents; i+ ) output += n学生的平均分 + i + 组是 + average( grades i ); outputArea.setFont( new Font( Courier, Font.PLAIN, 12 ) ); outputArea.setText( output ); /找最底分 public int minimum() int lowGrade = 100; for ( int i = 0; i students; i+ ) for ( int j = 0; j exams; j+ ) if ( grades i j lowGrade ) lowGrade

20、= grades i j ; /*FILL*/ return _lowGrade_; /找最高分 public int maximum() int highGrade = 0; for ( int i = 0; i students; i+ ) for ( int j = 0; j highGrade ) highGrade = grades i j ; return highGrade; /对各组学生确定平均分 public double average( int setOfGrades ) int total = 0; for ( int i = 0; i setOfGrades.leng

21、th; i+ ) total += setOfGrades i ; /*FILL*/ return ( double ) total / _setOfGrades.length_; /输出格式 public void buildString() output += ; for ( int i = 0; i exams; i+ ) output += + i + ; for ( int i = 0; i students; i+ ) output += ngrades + i + ; for ( int j = 0; j exams; j+ ) output += grades i j + ;

22、14.import javax.swing.JOptionPane;public class Java_3 public static void main( String args ) String firstNumber, /存储第1个输入数据 secondNumber, /存储第2个输入数据 /*FILL*/ _result_; /字符串输出 int number1, /用来比较的第1个int型数据 number2; /用来比较的第2个int型数据 /以字符串格式读输入数据 firstNumber = JOptionPane.showInputDialog( 请输入第1个整数: ); secondNumber = JOptionPane.showInputDialog( 请输入第2个整数: ); /将字符串转换为int整数 /*FILL*/ number1 = Integer.parseInt( _firstNumber_ ); /*FILL*/ number2 = Integer.parseInt( _secondNumber_ ); /用空字符串初始化结果变量 result = ; if ( number1 = number2 ) result = number1