OldSchoolCode

structs can be thought of as a container for multiple variables. Lets say you have to keep track of 10 different people. For each one you need to know their name, age, sex, weight. This would be a ton of variables to keep around. You would need 10 different variables for the name, 10 different for ages, 10 different for sex, etc...

Instead you can declare a struct that holds these variables. (also called member variables because they are members of the struct)

struct Person
{
   char name[ 64 ];
   int age;
   char sex;
   int weight;
};

Then, to use it, you make instances of the struct..

//customer1 is now an instance of the Person struct.
Person customer1;

//access the member variables of the struct with the period (dot)
customer1.age = 45;
customer1.sex = 'M';
customer1.weight = 315;
 
strcpy( customer1.name, "John" );
 
//neat huh? now to print them out you can do...
printf( "age: %d", customer1.age );

now lets say you want to use pointers...

Person *pCustomer = &customer1;

above, pCustomer now points to memory the address of (&) customer 1. You can still access the member variables, but you have to use the -> arrow. (minus sign and greater than sign)

printf( "Age : %d", pCustomer->age );

__________________________________________________________

//This program will allow the user to
//input up to 10 customers and then print them all out.
#define _CRT_SECURE_NO_DEPRECATE

#include <string.h>
#include <stdio.h>
#include <conio.h>
   
struct Person
{
   char name[64];
   int age;
   char sex;
   int weight;
};

void PrintCustomerStruct( Person *pCustomer, int count )
{
   int i;
	
   for ( i = 0; i < count; i++ )
   {
       printf( "\n Name : %s", pCustomer[ i ].name );
       printf( "\n Age : %d", pCustomer[ i ].age );
       printf( "\n Sex: %c", pCustomer[ i ].sex );
       printf( "\n Weight : %d", pCustomer[ i ].weight );
   }
}
      
void main( void )
{
   int count = 0;
   int stop;
	
   Person customer[ 10 ];
	
   do
   {
      Person *pCustomer = &customer[ count ];
		
      printf( "\n Enter name :" );
      scanf( "%s", &pCustomer->name );
      fflush( stdin );
      
      printf( "\n Enter age :" );
      scanf( "%d", &pCustomer->age );
      fflush( stdin );

      printf( "\n Enter sex, M or F :" );
      scanf( "%c", &pCustomer->sex );
      fflush( stdin );
      
      printf( "\n Enter weight :" );
      scanf( "%d", &pCustomer->weight );
      fflush( stdin );

      count++;

      if ( count < 10 )
      {
          printf( "\n Continue? 1=yes or 2=no :" );
          scanf( "%d", &stop );
      }
   }
   while ( stop == 1 && count < 10 );
	
   PrintCustomerStruct( customer, count );

   getch( );
}