all about c++ programming language

 

C++ Introduction



What is C++?

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

C++ was developed by Bjarne Stroustrup, as an extension to the C language.

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

The language was updated 4 major times in 2011, 2014, 2017, and 2020 to C++11, C++14, C++17, C++20.


Why Use C++

C++ is one of the world's most popular programming languages.

C++ can be found in today's operating systems, Graphical User Interfaces, and embedded systems.

C++ is an object-oriented programming language which gives a clear structure to programs and allows code to be reused, lowering development costs.

C++ is portable and can be used to develop applications that can be adapted to multiple platforms.

C++ is fun and easy to learn!

As C++ is close to C# and Java, it makes it easy for programmers to switch to C++ or vice versa.


Difference between C and C++

C++ was developed as an extension of C, and both languages have almost the same syntax.

The main difference between C and C++ is that C++ support classes and objects, while C does not.


C++ Get Started

To start using C++, you need two things:

  • A text editor, like Notepad, to write C++ code
  • A compiler, like GCC, to translate the C++ code into a language that the computer will understand

There are many text editors and compilers to choose from. In this tutorial, we will use an IDE (see below).


C++ Install IDE

An IDE (Integrated Development Environment) is used to edit AND compile the code.

Popular IDE's include Code::Blocks, Eclipse, and Visual Studio. These are all free, and they can be used to both edit and debug C++ code.

Note: Web-based IDE's can work as well, but functionality is limited.

We will use Code::Blocks in our tutorial, which we believe is a good place to start.

You can find the latest version of Codeblocks at http://www.codeblocks.org/. Download the mingw-setup.exe file, which will install the text editor with a compiler.


C++ Quickstart

Let's create our first C++ file.

Open Codeblocks and go to File > New > Empty File.

Write the following C++ code and save the file as myfirstprogram.cpp (File > Save File as):

myfirstprogram.cpp

#include <iostream>
using namespace std;

int main() {
  cout << "Hello World!";
  return 0;
}

Don't worry if you don't understand the code above - we will discuss it in detail in later chapters. For now, focus on how to run the code.

In Codeblocks, it should look like this:

Then, go to Build > Build and Run to run (execute) the program. The result will look something to this:


Hello World!
Process returned 0 (0x0) execution time : 0.011 s
Press any key to continue.

Congratulations! You have now written and executed your first C++ program.


C++ Syntax

Let's break up the following code to understand it better:

Example

#include <iostream>
using namespace std;

int main() {
  cout << "Hello World!";
  return 0;
}
Try it Yourself »

Example explained

Line 1: #include <iostream> is a header file library that lets us work with input and output objects, such as cout (used in line 5). Header files add functionality to C++ programs.

Line 2: using namespace std means that we can use names for objects and variables from the standard library.

Don't worry if you don't understand how #include <iostream> and using namespace std works. Just think of it as something that (almost) always appears in your program.

Line 3: A blank line. C++ ignores white space. But we use it to make the code more readable.

Line 4: Another thing that always appear in a C++ program, is int main(). This is called a function. Any code inside its curly brackets {} will be executed.

Line 5: cout (pronounced "see-out") is an object used together with the insertion operator (<<) to output/print text. In our example it will output "Hello World".

Note: Every C++ statement ends with a semicolon ;.

Note: The body of int main() could also been written as:
int main () { cout << "Hello World! "; return 0; }

Remember: The compiler ignores white spaces. However, multiple lines makes the code more readable.

Line 6: return 0 ends the main function.

Line 7: Do not forget to add the closing curly bracket } to actually end the main function.


Omitting Namespace

You might see some C++ programs that runs without the standard namespace library. The using namespace std line can be omitted and replaced with the std keyword, followed by the :: operator for some objects:

Example

#include <iostream>

int main() {
  std::cout << "Hello World!";
  return 0;
}







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