#include<iostream>
#include<string>
using namespace std;
//This program demonstrates the basics of structures
/* A structure is a compound variable. Itcan be used to group a number of data
 * elements, possibly of varying types into one unit. 
 * A declaration of a structure serves as a blueprint for the unit and does not
 * actually declare/ allocate space.
 *Ideally, structures are declared in global space, in order to facilitate use
 * throughout the program.
 * This structure can then be used as a programmer defined data type.
 * Since no space is allocated while declaring a structure, we cannot give values
 * to the data on the inside, unless they are consts.
 */
struct Date	//makes a date structure
{
	int day, month, year; //These won't be given values here
	string dayOfWeek;
}d1; //d1 becomes a global varibale of type Date

//We can also declare structure variables in another structure declaration
struct Person
{
	string name;
	double height,weight;
	string eyeColor;
	Date dateOfBirth;
}; //the semicolon is necessary
	
int main()
{
	//In order to allocate space, we need to create variables of the type
	Date today;
	Person me;
	
	//The . (dot) operator is used to access elements within the structure. 
	
	today.day=27;
	today.month=3;
	today.year=2017;
	today.dayOfWeek="Monday";

	//Input and output work the same way as primitives
	cout<<"Enter person info: ";
	cout<<"Name: ";
	getline(cin,me.name);
	cout<<"Height and Weight: ";
	cin>>me.height>>me.weight;
	cout<<"Eye Color: ";
	getline(cin,me.eyeColor);// to get rid of newline
	getline(cin,me.eyeColor);
	cout<<"Date of birth: ";
	//In order to use multiple level structures, we can use the dot operator for each level
	cout<<"Month: ";
	cin>>me.dateOfBirth.month;
	cout<<"Day: ";
	cin>>me.dateOfBirth.day;
	cout<<"Year: ";
	cin>>me.dateOfBirth.year;
 	
	//Output
	cout<<"Personnel Information:\nName: "<<me.name<<"\nDate of Birth: "<<me.dateOfBirth.month<<"-"<<me.dateOfBirth.day<<"-"<<me.dateOfBirth.year<<endl;
	
	return 0;
}