BASIC STRUCTURE OF PROGRAM IN C++

#include<iostream>

using namespace std;

int main()

{

........................

........code........

........................

return0;

}

§  '#' is a preprocessor that indicates that instructions for complier.

§  'include' is a keyword that’s mean to add anything.

§  'iostream' is a header file.

Header File:

            "Files that contain the Declaration of build in function"

                                               

Header files are the build in files that have some build in instructions or function or meanings of some build in function or the rules of using those keywords

It also has ".h" extension.

That files are build by the programmer or manufacturer of the compiler.

§  "iostream" contains all build in information about input and output functions that are used in the program by the programmer or a user of compiler.

§  'using' is a keyword that specify the directory to compiler to which directory is used in "iostream".

§  'namespace' is a name of directory that are being used by the compiler.

§  'std' mean standard library of a header file.

Keyword:

            Keyword or reserved words are the words, which have pre-defined meaning in any high level programming language.

Directory:
A directory is defined as an organizational unit, or container, used to organize folder and files into a hierarchical structure.
A directory contains bookkeeping information about files that are, figuratively speaking, beneath them in the hierarchy. You can think of a directory as a file cabinet that contains folders that contain files.

FUNCTION main ():

·         Main () is a function where the execution of the program are started. Every program has a main () function.

·    It acts like a main gate of a house. Main () is a starting point of program instructions. It is a entry point of the program.

·         The definition of the main function is always start with a reserved words (function return type) like (void, int , float and char) that are also  data types.In programming when void is used as a function return type,it indicates that the function does not return any value.

Void:
            In programming when void is used as a function return type,it indicates that the function does not return any value.
Void as a Function Return Type:

Void functions, also called non-value-returning functions, are used just like value-returning functions except void return types do not return a value when the function is executed. The void function accomplishes its task and then returns control to the caller.

Int as a Function Return Type:

            Int function is a value-returning function. It returns an integer type value after the execution of the whole body of the program. In ‘int main () ‘we ask the compiler after the end of program you return any integer type value.

After the execution of the program lines (statements), we use ‘return’ keyword that is used to return any value to compiler. Return follows any integer type value.

Delimiters:

After a main () function the instructions are written in the parenthesis {}. The rest of the lines of program form the body of the main function, the body is started by the opening parenthesis and end by the closing parenthesis.

Braces indicate the beginning and end of the function body. These braces are called delimiters.

Statement Terminator:

            Every statement in a C++ program terminates with the semicolon (;). If any of the statement missing the statement terminator, the compiler will report an error.