// Lab 1 Lecture

// ---------------------------- Data Types ------------------------------------

// We will come across several different types of data while programming.
// The computer uses these data types differently, so it is important to know
// which is appropriate to use.

// There are several basic data types provided by C++ programming language
// called primitive data types (also known as fundamental data types).

// Group           Type Name         Examples
// _________________________________________________________________________
// Integers       - int    - (whole numbers) - 1, 57, 5312
// Floating point - float  - (numbers with a decimal point) - 4.5, 2.123
// Floating point - double - (Numbers with a decimal point) - 4.5, 3.14159
// Character      - char   - (letters, symbols, and numbers) - 'x', '5', '$'
// Boolean        - bool   - (true or false) 1, 0, true, false

// You may have noticed that there are two floating point data types
// 'float' and 'double'. Their only difference is the amount of memory
// they use to store the data. Double type data uses twice the memory
// as float type and thus is more precise when calculating small fractions.


// ---------------------------- Literals ------------------------------------

// A literal is a fixed value that the programmer has written directly
// into the program.

#include <iostream>

using namespace std;

int main(){

	// here the number 5.32 is a floating point literal
	cout << 5.32 << endl;

	// here the number 5 is an integer literal
	cout << 5 << endl;

	// here the character 5 is a character literal. Notice that the single
	// quotes around it indicate that it is a character and not a number.
	cout << '5' << endl;

	// here "hello world" is a string data type. It is not a primitive data
	// type and so we did not cover it earlier. Notice that a string 
	// is indicated with a pair of double quotes (""). The iostream library 
	// provides the string data type for us. 
	cout << "hello world" << endl;


// ---------------------------- Variables ------------------------------------

	// Variables are storage locations or containers that are given a name
	// (identifier) so that they may be easily referenced to in your program.

	// "Type" is the data type that will be stored in the variable and the "name"
	// is the identifier given to reference it. A variable name can only include 
	// alphabet letters, numbers and the underscore character (_). Also,
	// a variable name cannot start with a number. 

	// To declare (create) a variable the following syntax can be used:

//  Type    Name
	int    myint;

	// This creates a variable called "myint" that will hold an integer.
	// We can now assign a value to it using the assignment operator (=).
	myint = 5;

	// we have now put the value 5 into our variable "myint".

	// We can also declare and initialize a variable at the same time using the
	// following syntax :

//  Type   Name    A.O.  Value    (A.O. = Assignment Operator)
	float  myfloat  =   5.34;

	// *Note* the value 5.34 is a literal we are assigning to the variable "myfloat"
	

// ---------------------------- Named Constants -------------------------------

// Sometimes we do not want a variable to change after it has been created.
// A named constant is simply a variable that cannot change after being
// declared and initialized. To make a variable constant simply put the
// identifier 'const' before the variable declaration.

// For example the value of pi will never change and so we want to make sure
// that we never accidentally modify it. Therefore We should make it constant.

	const double PI = 3.14159;

// *note* it is common style for programmers to name a constant in all capital
// letters to remind themselves that the variable is a constant.


// ------------------------------ Example -------------------------------------

// Example of a program printing literals and variables to the screen 
// using cout.

	// declaring two integer variables.
	int birthdayDay = 17;
	int birthdayYear = 1986;

	// declaring a string variable. 
	string birthdayMonth = "June";

	cout << "I was born on " << birthdayMonth << " " << birthdayDay << ", "
		 << birthdayYear << endl;

// ----------------------------------------------------------------------------

	return 0;
}