This tutorial will show you how to use class in C++.  This is the class standard format :

class name_of_class

{

private:

// write private variables or function here

public:

// write public variables or function here

};

The difference between class and struct is the visibility. Struct declaration is always public while class can be set into private or public. To understand more about class in C++, we will make a simple class to create Point3D data type just like what we do in constructor section. Suppose we want to create a constructor to handle 3D data type which contain coordinate X, Y and Z.

Add this to your header in .cpp file

#include <math.h>

Write this code in your .cpp.

// create a class to handle coordinates 3D
class Point3D
{
public:

// declare public variable coordinate X, Y and Z
float X;
float Y;
float Z;
float Magnitude;
// create an empty constructor
Point3D() { };
// create a constructor to fill Point3D data type
Point3D(float x, float y, float z)
{

X = x;
Y = y;
Z = z;
calcMagnitude();

};
// check if constructor is empty
bool isEmpty()
{

if (X != NULL && Y != NULL && Z != NULL)

return false;

return true;

};
// create a desctructor to destroy Point3D data type
~Point3D() { };

private:

// calculate magnitude from this point3D
void calcMagnitude()
{

Magnitude = isEmpty() ? 0 : sqrt(pow(X, 2) + pow(Y, 2) + pow(Z, 2));

}

};

// main function
int main(int argc, char** argv)
{

int key;
// create a Point3D data type named point
// insert X = 2.2, Y = 3.1 and Z = 4.5
Point3D point(2.2, 3.1, 4.5);
// read the value
cout << “The coordinate is P(“ << point.X << “,” << point.Y << “,” << point.Z << “)\n”;
cout << “The magnitude is “ << point.Magnitude << “\n”;

cout << “\nArray\n”;

// create an array of Point3D data type
Point3D* arrayPoint = new Point3D[10];
// fill the array of point using for loop
for (int i=0; i<10; i++)
{

arrayPoint[i] = Point3D(i, i, i);
cout << “The coordinate in P” << i << ” is (“ << arrayPoint[i].X << “,” << arrayPoint[i].Y << “,” << arrayPoint[i].Z << “)\n”;

}
// don’t forget to destroy the array if it is not used
delete[] arrayPoint;

cout << “\nVector\n”;

// create vector of Point3D data type
vector<Point3D> listPoint;
// fill the vector of point using for loop
for (int i=0; i<10; i++)
{

listPoint.push_back(Point3D(i, i, i));
cout << “The coordinate in P” << i << ” is (“ << listPoint[i].X << “,” << listPoint[i].Y << “,” << listPoint[i].Z << “)\n”;

}
// don’t forget to empty the vector if it is not used
listPoint.clear();

cin >> key;

return 0;

}

This is the result :

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This tutorial will show you how to use function in C++. We will make a simple function to write text in our console. This is the function standard format :

output function_name(input1, input2, …)

{

// write your code here

return output

}

Now we will create function to write a string in a specific coordinate in our console.

Add this to your .cpp header

#include <Windows.h>

Now write this in your .cpp

// A function to go to point (x, y) on console
void goTo(int xLine, int yLine)
{

COORD coord = {xLine, yLine};
SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), coord);

}

// A function to write a text on specific point on console
void writeText(int xLine, int yLine, string text)
{

goTo(xLine, yLine);
cout << text << flush;

}

// main function
int main(int argc, char** argv)
{

int key;
string text = “Hello World!”;
writeText(20, 10, text); // write text in point (20, 10)
writeText(40, 30, “Hello World!!”); // write text in point (40, 30)

cin >> key;

return 0;

}

This is the result

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This tutorial will show you how to use struct to create a constructor in C++. We assume that you have already done the previous tutorial.

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Constructor

You can use class or struct to create a constructor. The general format is :

struct name_of_constructor

{

// declare the variables here

name_of_constructor() { } // create empty constructor

~name_of_constructor() { } // create destructor

};

Suppose we want to create a constructor to handle 2D data type which contain coordinate X and Y. Write this code in your .cpp.

// create a constructor to handle coordinates 2D
struct Point2D
{

// declare local variable coordinate X and Y
int X;
int Y;
// create an empty constructor
Point2D() { }
// create a constructor to fill Point2D data type
Point2D(int x, int y)
{

X = x;
Y = y;

}
// create a desctructor to destroy Point2D data type
~Point2D() { };

};

// main function
int main(int argc, char** argv)
{

int key;
// create a Point2D data type named point
// insert X = 2 and Y = 3
Point2D point(2, 3);
// read the value
cout << “The coordinate is P(“ << point.X << “,” << point.Y << “)\n”;

cout << “\nArray\n”;

// create an array of Point2D data type
Point2D* arrayPoint = new Point2D[10];
// fill the array of point using for loop
for (int i=0; i<10; i++)
{

arrayPoint[i] = Point2D(i, i);
cout << “The coordinate in P” << i << “is (“ << arrayPoint[i].X << “,” << arrayPoint[i].Y << “)\n”;

}
// don’t forget to destroy the array if it is not used
delete[] arrayPoint;

cout << “\nVector\n”;

// create vector of Point2D data type
vector<Point2D> listPoint;
// fill the vector of point using for loop
for (int i=0; i<10; i++)
{

listPoint.push_back(Point2D(i, i));
cout << “The coordinate in P” << i << “is (“ << listPoint[i].X << “,” << listPoint[i].Y << “)\n”;

}
// don’t forget to empty the vector if it is not used
listPoint.clear();

cin >> key;

return 0;

}

The result is :

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This tutorial will show you how to use array and vector in C++. We assume that you have already done the previous tutorial.

---

Array

The general array declaration format is :

 type_array_data_with_pointer name_of_array = new type_array_data[number_of_array_allocation];

This code will show how to initialize an array and allocate array with for loop. In your main function :

// main function
int main(int argc, char** argv)
{

int key;
// array declaration
int* data = new int[10];
// use for loop to fill the array one by one
for (int i=0; i<10; i++)
{

// fill the i-th data with a value
data[i] = i;
// show the value inside i-th data
cout << “value inside “ << i << “-th data is “ << data[i] << “\n”;

}

cin >> key;

return 0;

}

The result is :

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Vector

The general vector declaration format is :

// this declaration will create dynamic vector

vector<type_vector_data> name_of_vector;

// this declaration will create static vector

vector<type_vector_data> name_of_vector(number_of_vector_allocation);

This code will show how to initialize dynamic vector and allocate vector with for loop. In your main function :

// main function
int main(int argc, char** argv)
{

int key;
// dynamic vector declaration
vector<int> data;
// use for loop to fill the vector one by one
for (int i=0; i<10; i++)
{

// fill the i-th data with a value
data.push_back(i);
// show the value inside i-th data
cout << “value inside “ << i << “-th data is ” << data[i] << “\n”;

}

cin >> key;

return 0;

}

The result is :

This code will show how to initialize static vector and allocate vector with for loop. In your main function :

// main function
int main(int argc, char** argv)
{

int key;
// static vector declaration
vector<int> data(10);
// use for loop to fill the vector one by one
for (int i=0; i<10; i++)
{

// fill the i-th data with a value
// you can use this
data.at(i) = i;
// or this
data[i] = i;
// show the value inside i-th data
cout << “value inside “ << i << “-th data is “ << data[i] << “\n”;

}

cin >> key;

return 0;

}

The result is :

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This tutorial will show you how to use iteration in C++. We only cover iteration which most used in programming. We assume that you have already done the previous tutorial.

---

For Loop

The general format is :

for (initial condition; stopping condition; increment)

{

// write your code here

}

In your main function :

// main function
int main(int argc, char** argv)
{

int key;
// loop from i=0 until i<10 with increment i=i+1
for (int i=0; i<10; i++)
{

cout << “data number “ << i << “\n”;

}

cin >> key;

return 0;

}

The result is :

---

While Loop

The general format is :

// initialize stopping condition here;

while (stopping condition is false)

{

// write your code here

// if (condition met)

//          stopping condition is true;

}

In your main function :

// main function
int main(int argc, char** argv)
{

int key;
// loop from i=0 until i<10
int i = 0; // initialize variable for stopping condition
while (i < 10) // i < 10 is the stopping condition
{

cout << “data number “ << i << “\n”;
i++; // increment i

}

cin >> key;

return 0;

}

The result is :

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This tutorial will show you how to use conditional statements in C++. We only cover conditional statements which most used in programming. We assume that you have already done the previous tutorial.

---

If Else

The general format is :

if (condition 1) statement 1;

else if (condition 2) statement 2;

else statement 3;

In your main function :

// main program
int main(int argc, char** argv)
{

// \n is enter; \t is tab
cout << “Conditional Statements Demo\n\n”;
cout << “Information :\n”; // display text
cout << “Hello\t<Press 1>\n”;
cout << “Exit\t<Press 0>\n\n”;
cout << “Key Command : “;
cin >> key; // take integer input

/////////////////////////////////////////////////////////////////
// conditional statements
// if condition 1 then statement 1
if (key == 0)

exit(0);

// if condition 2 then statement 2
else if (key == 1)
{

text = “Hello World!”;
cout << “\n” << text;

}
// otherwise
else
{

text = “Press 1 or 0”;
cout << “\n” << text;

}
/////////////////////////////////////////////////////////////////

cout << “\n\n” << “Press any key to exit…”;
cin >> key;

return 0;

}

---

Switch Case

The general format is :

switch (input condition)

{

case condition 1 : statement 1; break;

case condition 2 : statement 2; break;

default : statement 3; break;

}

In your main function :

// main program
int main(int argc, char** argv)
{

// \n is enter; \t is tab
cout << “Conditional Statements Demo\n\n”;
cout << “Information :\n”; // display text
cout << “Hello\t<Press 1>\n”;
cout << “Exit\t<Press 0>\n\n”;
cout << “Key Command : “;
cin >> key; // take integer input

/////////////////////////////////////////////////////////////////
// conditional statements
switch (key)
{
// if condition 1 then statement 1
case 0:

exit(0);
break;

// if condition 2 then statement 2
case 1:

text = “Hello World!”;
cout << “\n” << text;
break;

// otherwise
default:

text = “Press 1 or 0”;
cout << “\n” << text;
break;

}
/////////////////////////////////////////////////////////////////

cout << “\n\n” << “Press any key to exit…”;
cin >> key;

return 0;

}

---

Other kind

If there is a condition and two statement then you can use this format :

result = condition ? statement 1 : statement 2;

This format is equivalent to :

if (condition) statement 1;

else statement 2;

In your main function :

// main program
int main(int argc, char** argv)
{

// \n is enter; \t is tab
cout << “Conditional Statements Demo\n\n”;
cout << “Information :\n”; // display text
cout << “Hello\t<Press 1>\n”;
cout << “Exit\t<Press Anything>\n\n”;
cout << “Key Command : “;
cin >> key; // take integer input

/////////////////////////////////////////////////////////////////
// conditional statements
text = key == 1 ? “Hello World!” : “Press anything to exit…”;
/////////////////////////////////////////////////////////////////

cout << “\n\n” << text;
cin >> key;

return 0;

}

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After you have done the previous tutorial, we will write a simple program to display “Hello World!” text in our console. Here is the step :

• Assume you already have an empty .cpp file in the previous tutorial.
• C++ file usually has three important parts : header declaration, variable initialization, and main function.

---

Header declaration

• We declare all necessary header which used in our program.
• To display “Hello World!” text in our program, we need standard input/output library and string library.
• Here is the header that will be used:

// header declaration
#include <iostream> // handle standard input/output
#include <string> // handle string type

using namespace std;

---

Variable initialization

• We initiate all variable (global) which used in our program.
• Here is the variables that will be used :

// variable initialization
string text;
int key;

---

Main function

• We write our program in the main function because this function will be the first function to be executed after the program running.
• Here is the program to display “Hello World!” text in our console :

// main program
int main(int argc, char** argv)
{

text = “Hello World!”; // text that will be displayed
cout << text; // display text

cin >> key; // take integer input

return 0;

}

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Executing the program

• In Visual Studio, we run the program by clicking green play button.

• And the result is :

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We can write a program with C++ language using Visual Studio C++. Here is the configuration :

• Open Visual Studio C++.
• Create a C++ project and select Win32 console application.
• Give a name to the project (without space or characters) then click OK.

• Click Next — select Console Application — check Empty project — click Finish.

• Now you are done creating empty project in Visual C++.
• Go to Solution Explorer — Source Files — Right click — Add — New Item.

• Select C++ File (.cpp) file then give it a name — click Add

• You will get a .cpp file in your project. The Source Files is a folder where you put all your .cpp / .c / .cu files and the Header Files is a folder where you put all your .h / .hpp / .cuh files
• Now you good to go to the coding tutorial.

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