==============================MODULE11=====================================
|                                                                         |
|  The program examples' source codes have been arranged in the same      |
|  order that appeared in the Tutorial. This is unedited and unverified   |
|  compilation. Published as is basis for educational, reacretional and   |
|  brain teaser purposes. All trademarks, copyrights and IPs, wherever    |
|  exist, are the sole property of their respective owner and/or          |
|  holder. Any damage or loss by using the materials presented in this    |
|  tutorial is USER responsibility. Part or full distribution,            |
|  reproduction and modification is granted to any body.                  |
|     Copyright 2003-2005 © Tenouk, Inc. All rights reserved.		  |
|          Distributed through http://www.tenouk.com			        |
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===========================================================================
Originally programs compiled using Borland C++. Examples compiled using
VC++/VC++ .Net and gcc or g++ are given at the end of every Module.
For example if you want to compile C++ codes using VC++/VC++ .Net, change
the header file accordingly.  Just need some modification for the header
files...:

-------------------------------------------------
#include <iostream.h>
//for system()
#include <stdlib.h>

...
{
C++ codes...
}
-------------------------------------------------
should be changed to:
-------------------------------------------------
#include <iostream>
//use C++ wrapper to call C functions from C++ programs...
#include <cstdlib>
using namespace std;

...
{
C++ codes...
}
-------------------------------------------------
In VC++/VC++ .Net the iostream.h (header with .h) is not valid anymore.
It should be C++ header, <iostream> so that it comply to the standard.
In older Borland C++ compiler this still works, but not proper any more...
and for standard C/C++ the portability should be no problem or better
you read Module23 at http://www.tenouk.com/Module23.html to get
the big picture...For C codes, they still C codes :o)
=========================================================================
=========================================================================

//A simple structure program example
#include <stdio.h>
#include <stdlib.h>

struct student{
	char id_num[6];
	char name[11];
	char gender;
	int age;
	};

int main(void)
{
struct student studno_1;

//studno_1.id_num = "A3214";	//Illegal, const char to char[]
//studno_1.name = "Smith";	//Illegal, const char to char[]
printf("Enter student ID num (5 max): ");
scanf("%s", studno_1.id_num);
printf("Enter student name (10 max): ");
scanf("%s", studno_1.name);
studno_1.gender = 'M';
studno_1.age = 30;

printf("\n------------------\n");
printf("ID number: %s\n", studno_1.id_num);
printf("Name     : %s\n", studno_1.name);
printf("Gender   : %c\n", studno_1.gender);
printf("Age      : %d\n", studno_1.age);
printf("------------------\n");
system("pause");
return 0;
}

---------------------------------------------------------------------------

//accessing structure element.  Change the
//header files accordingly for VC++/VC++ .Net
//#include <iostream>
//#include <cstdlib>
//using namespace std;

#include <iostream.h>
#include <stdlib.h>

struct Card
{
   char  *face;  //pointer to char type
   char  *suit;  //pointer to char type
};

void main()
{
     //declare the struct type variables
     struct Card  p;
     struct Card  *SPtr;

 	p.face = "Ace";
 	p.suit = "Spades";
 	SPtr = &p;
       
   cout<<"Accessing structure element:\n";
   cout<<"\n\'SPtr->suit\'  = "<<SPtr->suit<<endl;
   cout<<"\'SPtr->face\'  = "<<SPtr->face<<endl;
   //for Borland... 
   system("pause");
}

-------------------------------------------------------------------------------------------------------

//Using the structure member and structure
//pointer operators – accessing structure
//elements styles...
#include <iostream.h>
#include <stdlib.h>

struct Card
{
	char  *face;
	char  *suit;
};

int main()
{
	struct Card  p;
	struct Card  *SPtr;

	p.face = "Ace";
	p.suit = "Spades";
	SPtr = &p;

cout<<"Accessing structure element styles"<<endl;
cout<<"----------------------------------"<<endl;
cout<<"Style #1-use p.face:       "<<p.face<<" of "<<p.suit<<endl;
cout<<"Style #2-use Sptr->face:   "<<SPtr->face<<" of "<<SPtr->suit<<endl;
cout<<"Style #3-use (*Sptr).face: "<<(*SPtr).face<<" of "<<(*SPtr).suit<<endl;
system("pause");
return 0;
}

-------------------------------------------------------------------------------------------------------

//an array structure of student information
#include <iostream.h>
#include <stdlib.h>
//for C++ replace to the following header
//#include <iostream>
//#include <cstdlib>
//using namespace std;

struct student
{
	char id[6];      //student id number, max. 5 integer number
	char name[50];   //student name, max 49 characters
	char gender;     //student gender Male or Female
	int  age;        //student age
};

void main()
{
	//declaring array of 10 element of structure type
	//and some of the element also are arrays
	struct student stud[10];
	int i = 0;

	cout<<"Keying in student data and then display\n";
	cout<<"---------------------------------------\n";
	cout<<"Enter student data\n";

	for(i=0; i<2; i++)
	{
		//Storing the data
		cout<<"\nID number (4 integer number) student #"<<i<<": ";
		cin>>stud[i].id;
		cout<<"First name student #"<<i<<": ";
		cin>>stud[i].name;
		cout<<"Gender (M or F) student #"<<i<<": ";
		cin>>stud[i].gender;
		cout<<"Age student #"<<i<<": ";
		cin>>stud[i].age;
}

	cout<<"\n----------Display the data---------\n";
	cout<<"You can see that the data storage\n";
	cout<<"has been reserved for the structure!\n";
	cout<<"------------------------------------\n";
	for(i=0; i<2; i++)
	{
	//Displaying the stored data
	cout<<"\nID number student  # "<<i<<": "<<stud[i].id;
	cout<<"\nFirst name student # "<<i<<": "<<stud[i].name;
	cout<<"\nGender student     # "<<i<<": "<<stud[i].gender;
	cout<<"\nAge student        # "<<i<<": "<<stud[i].age<<"\n";
	}
	system("pause");
}

-----------------------------------------------------------------------------------------------------------

//passing structures to functions and
//a function returning a structure
#include <iostream.h>
#include <stdlib.h>
#include <stdio.h>


//--------structure part--------
struct vegetable
{
	char   name[30];
	float  price;
};

//--------main program---------
int main()
{
	//declare 2 structure variables
	struct vegetable veg1, veg2;
	//function prototype of type struct
	struct vegetable  addname();
	//another function prototype
	int list_func(vegetable);

	//functions call for user input...
	veg1  =  addname();
	veg2  =  addname();
	cout<<"\nVegetables for sale\n";
	
	//function call for data display...
	list_func(veg1);
	list_func(veg2);
	cout<<endl;
    //for Borland
	system("pause");
	return  0;
}
//-------------function----------------
//This functions returns a structure
struct vegetable addname()
{
	char  tmp[20];
	//declare a structure variable
	struct vegetable vege;

	cout<<"\nEnter name of vegetable:  ";
	gets(vege.name);
	cout<<"Enter price (per 100gm):  $ ";
	gets(tmp);
	//converts a string to float
	vege.price = atof(tmp);
	return (vege);
}

//structure passed from main()
int list_func(vegetable list)
{
	cout<<"\nVegetable name:  "<<list.name;
	cout<<"\nVegetable price:  $"<<list.price;
	return 0;
}

---------------------------------------------------------------------------------------------------------

//typedef and struct program example
#include <stdio.h>
#include <stdlib.h>

typedef struct TestStruct
{
   int    p;
   char   q;
   double r;
} mine;

void main()
{
  mine testvar; //the declaration becomes simpler
  testvar.p = 200;
  testvar.q = 'T';
  testvar.r = 1.234;
  printf("%d\n%c\n%.4f\n", testvar.p, testvar.q,testvar.r);
  system("pause");
}

-------------------------------------------------------------------------------------------------------

//typedef specifier
#include <stdio.h>

typedef struct mystructtag 
{
   int    x;
   double y;
   char*  z; 
} mystruct;

int main() 
{
   mystruct Test1, *Test2;
   Test1.x = 111;
   Test1.y = 1.111;
   printf("Test1.x = %d\nTest1.y = %f\n", Test1.x, Test1.y);
   
   Test1.z = "This is a string";
   Test2 = &Test1;
   printf("Test1->z = %s\n", Test2->z);
   return 0;
}

-----------------------------------------------------------------------------------------------------------

#include <iostream.h>
#include <stdlib.h>

enum days {mon = 1,tue,wed,thu,fri,sat,sun};

void main()
{
	//declaraing enum data type
	enum days day_count;

	cout<<" Simple day count\n";
	cout<<"    using enum\n";

	for(day_count=mon;day_count<=sun;day_count++)
	cout<<"  "<<day_count<<"\n";
	system("pause");
}

---------------------------------------------------------------------------------------------------------------

//enum declarations
#include <iostream>
using namespace std;

//Declare enum data type Days
enum Days               
{
	monday,		//monday = 0 by default 		              
	tuesday = 0,	//tuesday = 0 also			            
	wednesday,	//wednesday = 1 		          
	thursday,	//thursday = 2 		
	friday,		//an so on.
	saturday,
	sunday
};

int main() 
{
	//try changing the tuesday constant,
	//recompile and re run this program
	enum Days WhatDay = tuesday;
	switch (WhatDay)
	{
		case 0:
		cout<<"It's Monday"<<endl;
		break;
		default:
		cout<<"Other day"<<endl;
	}
return 0;
}

----------------------------------------------------------------------------------------------------------

//enum definition
#include <iostream>
using namespace std;

enum FileOpenFlags
{
	//defined here...
	OpenReadOnly  = 1,
	//using OpenReadOnly as the next initializer
	//and so on...
	OpenReadWrite = OpenReadOnly,
	OpenBinary = OpenReadWrite,
	OpenText = OpenBinary,
	OpenShareable = OpenText
};

int main()
{
	return 0;
}
//No output

-------------------------------------------------------------------------------------------------------------

//enumeration data type
#include <iostream>
using namespace std;

enum Days
{
    
    Tuesday,
    Wednesday,
    Thursday,
    Friday,
    Saturday,
           Sunday,
    Monday
};

int  i;
Days d = Thursday;
int main()
{
//Converted by integral promotion.
i = d;
cout<<"i = "<<i<<"\n";
return 0;
}

-------------------------------------------------------------------------------------------------------------

#include <stdio.h>
#include <stdlib.h>

typedef enum {
	FailOpenDisk = 1,
	PathNotFound,
	FolderCannotBeFound,
	FileCannotBeFound,
	FailOpenFile,
	FileCannotBeRead,
	DataCorrupted
} ErrorCode;

int main(void)
{
ErrorCode MyErrorCode;

for(MyErrorCode=FailOpenDisk; MyErrorCode<=DataCorrupted; MyErrorCode++)
	printf(" %d", MyErrorCode);
   printf("\n");
system("pause");
return 0;
}

---------------------------------------------------------------------------------------------------------------

#include <iostream.h>
#include <stdlib.h>

union  sample
{
	int  p;
	float q;
	double r;
};

void main()
{
	//union data type
	union sample content;

	content.p = 37;
	content.q = 1.2765;

	cout<<"Display the union storage content\n";
	cout<<"      ONLY one at a time!\n";
	cout<<"---------------------------------\n";
	cout<<"Integer: "<<content.p<<"\n";
	cout<<"Float  : "<<content.q<<"\n";
	cout<<"Double : "<<content.r<<"\n";
	cout<<"See, some of the contents are rubbish!\n";

	content.q=33.40;
	content.r=123.94;

	cout<<"\nInteger: "<<content.p<<"\n";
	cout<<"Float  : "<<content.q<<"\n";
	cout<<"Double : "<<content.r<<"\n";
	cout<<"See another inactive contents, rubbish!\n";
	cout<<"\nBetter use struct data type!!\n";
	system("pause");
}

------------------------------------------VC++/VC++ .Net------------------------------------------------------

//typedef specifier
#include <cstdio>

//typedef oldname newname
typedef struct mystructtag 
{
   int   x;
   double y;
   char* z; 
} mystruct;

int main() 
{
   mystruct Test1, *Test2;
   Test1.x = 111;
   Test1.y = 1.111;
   printf("Test1.x = %d\nTest1.y = %f\n", Test1.x, Test1.y);
   
   Test1.z = "This is a string";
   Test2 = &Test1;
   printf("Test1->z = %s\n",Test2->z);
   return 0;
}

----------------------------------------G++ on Linux/Fedora------------------------------------------------

///////typestruct.cpp///////////
//typedef specifier
#include <cstdio>
using namespace std;

//typedef oldname newname
typedef struct mystructtag
{
   int   x;
   double y;
   char* z;
} mystruct;

int main()
{
   mystruct Test1, *Test2;
   Test1.x = 111;
   Test1.y = 1.111;
   printf("Test1.x = %d\nTest1.y = %f\n", Test1.x, Test1.y);

   Test1.z = "This is a string";
   Test2 = &Test1;
   printf("Test1->z = %s\n", Test2->z);
   return 0;
}

============================================================================================================