3.4. Further Program examples.   

Looping contructs:

       type       dayname = (sunday,monday,...saturday)

                        workday = monday..friday

        var       wday:workday

                :

        wday  monday


        while wday != ? do

                        :     //  some processing

              wday  succ(wday)

        endwhile

                //  CAREFUL WITH OTHER CONSTRUCTS

 algorithm example


 type  sexstatus=(male,female)

       maritalstatus=(single,married,separated,divorced,widowed)


 var   quit,done:boolean

       sex,gender:sexstatus

       mstat1,mstat2:martialstatus


 begin

       /*  Booleans  */

       quit  true        /*  Assignment from a Boolean Constant  */

       done  quit       /*  Assignment from a Boolean Variable  */


       /*  sexstatus  */

       sex  female       /*  Assignment from a Sexstatus Constant  */

       gender  sex       /*  Assignment from a Sexstatus Variable  */


       /*  maritalstatus  */

       mstat1  single    /*  from Maritalstatus constant  */

       mstat2  widowed   /*  from maritalstatus constant  */

       mstat1  mstat2    /*  from VAR of type maritalstatus  */

       for mstat1  single to divorced do

             mstat2  mstat1

       /*   mstat1 single -> married

             married -> separated

             separated -> divorced   */

 endalgorithm  //  of example program.

(1) Comments about the purpose of sections of code:

/*  the following for loop could represent LIFE  */


  

/*  of loop that calculates mortgage interest  */


 

import local.units.sdsu.io.*;

import java.lang.*;

import java.io.*;


class       Sexstatus

{

     static final int MALE   =0;

     static final int FEMALE =1;

     int status;

}


public class Sexy1

{

// Mainline Variable Declarations

static PrintStream output = System.out;

static ASCIIInputStream input = new ASCIIInputStream(System.in);


static final int     max=7;                  //  7 characters only for reply

static Sexstatus sex = new Sexstatus();

static boolean error;

static int i,length;

static char ch;

static char string[] = new char[max];


     public static void main(String argv[]) throws IOException

     {

          do

          {

               error = false;

               Format.print(output,"Sex: ");output.flush();

               do

               {

                    ch = input.readChar();

               } while (ch == ' ');               //  skip blanks.


               i = 0;

               while ( (i<max) && (ch != '\n') )

               {

                    string[i] = Character.toLowerCase(ch);

                    i++;

                    ch = input.readChar();

               }

               if(ch != '\n')

                    input.flushLine();

               ch = string[0];               //  TEMP STORAGE FOR EFFICIENCY.

               //  Assume upper case only

               if ( (ch=='f') || (ch=='m') || (ch=='y') )

                    switch(ch)

                    {

                    case 'm':                //  look for 'ale'

                         if ( ( string[1] != 'a') || (string[2] != 'l') ||

                              (string[3] != 'e') ) error = true;

                         else sex.status = Sexstatus.MALE;

                         break;

                    case 'f':                //  look for 'emale'

                         if ( (string[1] != 'e') || (string[2] != 'm') ||

                              (string[3] != 'a') || (string[4] != 'l') ||

                              (string[5] != 'e') ) error = true;

                         else sex.status = Sexstatus.FEMALE;

                         break;

                    case 'y':                //  Person has typed YES please ...

                         Format.print(output,"Animal- What is your sex -\n");

                         error = true;

                         break;

                    }

               else        error = true;

               if ( error ) Format.print(output," Eh?\n");

          } while ( error);

          if (sex.status==Sexstatus.MALE ) Format.print(output,"I guess you are male.\n");

          else             Format.print(output,"I deduce you are female.\n");

     }

}

import local.units.sdsu.io.*;

import java.lang.*;

import java.io.*;


class       Sexstatus

{

     static final int MALE   =0;

     static final int FEMALE =1;

     int status;

}


public class Sexy2

{

// Mainline Variable Declarations

static PrintStream output = System.out;

static ASCIIInputStream input = new ASCIIInputStream(System.in);


static final int  max = 7;

static final String  SMALE   ="male";

static final String  SFEMALE ="female";

static Sexstatus sex = new Sexstatus();

static boolean error;

static int i,length;

static char ch;

static char string[] = new char[max];

static String response ;


     public static void main(String argv[]) throws IOException

     {

          do

          {

               error = false;

               Format.print(output,"Sex: ");output.flush();

               do

               {

                    ch = input.readChar();

               } while (ch == ' ');               //  skip blanks.


               i = 0;

               while ( (i<max) && (ch != '\n') )

               {

                    string[i] = Character.toLowerCase(ch);

                    i++;

                    ch = input.readChar();

               }

               if(ch != '\n')

                    input.flushLine();

               response = new String(string,0,i);

               if(response.equals(SMALE))        sex.status = Sexstatus.MALE;

               else if(response.equals(SFEMALE)) sex.status = Sexstatus.FEMALE;

               else

               {

                    Format.print(output,"Animal- What is your sex -\n");

                    error = true;

               }

               if ( error ) Format.print(output,"Eh?\n");


          } while ( error);

          if (sex.status==Sexstatus.MALE ) Format.print(output,"I guess you are male.\n");

          else             Format.print(output,"I deduce you are female.\n");

     }

}