Introduction to C++

C++ is a statically typed,general purpose programming language. C++ was derived C, band is largely based on it.

Note: A programming language is said to used static typing when type checking is performed during compile-time as opposed to run time.

Standard Libraries

Standard C++ has three important components

• Core language
  Provides all necessary building blocks, including variables, data types, literals, etc.
• Standard library
  Offers a rich set of functions for manipulating files, string, etc.
• Standard template library
  Offers methods for the manipulation of data structures, etc.

First program of C++:-

Write a program in C++ print a massage on output screen.

#include<iostream.h>
using namespace std;
int main()
{
    cout <<"Hello world";
    return();
}

Program Explanation

• Pound sign(#)
  The pound sign(#) at the beginning of a line targets the compiler's pre-processor to include the <iostream.h> header.

    #include<iostream.h>
  

C++ offers verious headers, each of which contains information need for programs to work properly. This particular program calls for the header file <iostream.h>.

The <iostream.h> header define the standard stream objects that input and output data.

• using namespace std;
  In our code, the line using namespace std; tells the compiler to use the std (standard) namespace. The std namespace includes features of the C++ standard library.

• main() function
  Program execution begins with the main() function. The entry point of every C++ program is main() function.

• Curly brackets {}
  Curly brackets {} indicate the beginning and end of a function, which can also be called the function's body. The information inside the brackets indicates what the function does when executed.

• cout<< "Hello world";
  cout<< "Hello world"; results in the display of Hello world to output screen.

• cout : is used in combination with the insertion operator

• Insertion operator << : Write the insertion operator as << to insert the data comes after cout into the stream the comes before.

• Semicolon (;)
  The semicolon (;) is used to terminate a statement.

• return 0;
  The last instruction in the program is the return statement. The line return 0; terminate the main() function and causes it to return value 0 to the calling process.