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.