Introduction To C++

C++ is a cross-platformed language that can be used to create sophisticated high-performance applications.

C++ was developed in Bell labs 1979 as an extension to its predecessor, the C language.

C++ gives programmers a high level of control over system resources and memory.

The language was updated 3 major times in 2011, 2014,and 2017 to C++11, C++14, and C++17.

Differences Between C and C++ Programming

Uses Of C++

Applications

C++ is used for the development of new applications of C++. Many applications of Adobe Systems are developed in C++ like Illustrator, adobe premiere and image ready

Games

C++ is used for developing games. It supports multiplayer option with networking. It is also used in developing the suites of a game tool.

Animations

There are animated software which are developed with the help of C++ language. 3D animation, modeling, simulation and rendering software.

Web Browser

 C++ is used for making Google Chrome and Mozilla Internet Browser Firefox.

Database Access

C++ is used for developing database software or open source database software. An example is MySQL which is the most popular database management system

Media Access

C++ is also used for creating media player, managing video files and audio files. An example is winamp media player which is developed in C++ language

Operating Systems

C++ is also used for developing most of the operating systems for Microsoft and few parts of Apple Operating System.

Advantages of C++

• Is a highly portable language and is often the language of selection for multi-device, multi-platform app development
• Is an object-oriented programming and includes concepts like classes, inheritance, polymorphism, data abstraction and encapsulation which allow code reusability and makes programs maintainable
• It gives the user complete control over memory management
• The wide range of applications: from GUI applications to 3D graphics for games to real-time mathematical simulations, C++ is everywhere

C++ Compilers

A compiler is a special program that processes statement written in a particular programming language and turns them into machine language (“code” made up of 0’s and 1’s that computer’s processor uses).

Figure: Compiler illustration

Creating Executable C++ File

The easiest way to compile C++ programs is by using an Integrated Development Environment (IDE). An IDE integrates several development tools, including a text editor and tools to compile programs directly from it.

IDE for Compiling C++ Programs

• Code::blocks
• Visual Studio Express
• Dev – C++

We will be using Code:blocks as our IDEfor this course.

Download Code::blocks at http://www.codeblocks.org/downloads/binaries

Get the one with the mingw-setup in the executable file name. That one comes with both the IDE and the compiler so you won't have to install another plugin for the compiler.

CREATING YOUR FIRST C++ PROGRAM

Start the CodeBlock

Figure: CodeBlock

To create a project, click on File -> New -> Project

Figure: New Project creation

Select the project type. 

We will be developing console applications in this course. So select the Console Application option.

Figure: Console Application

Click Next and select C++

Fill the Project Title, browse to where to save your project 

Figure: Project Creation Form 

Figure: Project Name Details

Click on next

 Figure: Compiler Selection Form

Click on Finish

Figure: main.cpp file to be edited

Variables

A variable provides name storage that programs can manipulate.

The name of a variable can be composed of letters,digits, and the underscore character. It must begin with either a letter or an underscore.Upper and lowercase letters are distinct because C++ is case-sensitive

Variable Types

Variable Definition

Variables are declared in the following formats.

Variabletype variable name;

Thus you enter the variable type and leave a space then type the name you want to assign to the variable and end thecommand with a semi column (;)

NOTE: ; is placed at the end of the programming command.

Examples of Variable Definition

int a;

int b;

int c;

int d;

You can also declare more than one variable at once by typing a comma after the previous variable name before typing the next variable name.

Thus the above variable declarations could be written as

int a,b,c,d;

More Examples

int    i, j, k;

char   c, ch;

float  f, salary;

double d;

Variable Scope

A scope is a region of the program. There are three places where variables can be declared.

• Inside a function or a block which is called local variables
• In the definition of function parameters which is called formal parameters
• Outside of all functions which is called global variables

Local Variables

Local Variables are declared inside a function or block. They can be used only by statements that are inside that function or block of code. Local variables are not known to functions outside their own.

Example

#include <iostream>
using namespace std;
int main () {
   // Local variable declaration:
     int a, b;
      int c;
     return 0;
}

Global Variables

Global variables are defined outside of all the functions, usually on top of the program. A global variable can be accessed by any function. A global variable is available for use throughout the entire program after its declaration.

#include <iostream>
using namespace std;
 
// Global variable declaration:
int g;
 
int main () {
   // Local variable declaration:
   int a, b;
 
   // actual initialization
   a = 10;
   b = 20;
   g = a + b;
  
   cout << g;
 
   return 0;
}

A program can have same name for local and global variables but value of local variable inside a function will take preference.

#include <iostream>
using namespace std;
 
// Global variable declaration:
int c = 5;
 
int main () {
   // Local variable declaration:
   int c = 2;
 
   cout << c;
 
   return 0;
}

The above program output will be 2 because the local variable declared (int c = 2)declared in the function will take preference.

Function Parameters

This will be elaborated more under the topic functions. 

Assignment 1

State a programming application that you will like to create and the possible variable names and their types to use. Write their declarations. Example

An application to register students