C Language Brief programming concept

C programming language was developed in 1972 by DENNIS RITCHIE in BELL LABORATORIES of AT&T(American telephone and telegraph)located in U.S.A. He is known as the founder of C language.

   

It was developed to overcome the problems of previous languages such as B, BCPL, etc.

Initially, C language was developed to be used in Unix Operating System. The main features of C language includes low level access to memory, a simple set to keywords, and clean styles, these features make C language suitable for system programmings like an operating system or compiler development. Many later languages have borrowed syntax/features directly or indirectly from C language. Like syntax of Java, PHP, JavaScript, and many other languages are mainly based on C language. C++ is nearly a super set of C language (There are few programs that may compile in C, but not in C++). 

      

Some components of writing program in certain manner are :

 1 . C Pre-processor Directives : Before a C program is compiled in a compiler , source code is processed by a program called pre-processor. This process is called pre-processing.Commands used in pre-processor are called pre-processor directives and they begin with “#” symbol .                                                       

Syntax :                                                                                                            #include<>                                                                                            

2. Header Files : The first component is the inclusion of the Header files in a C program.A header file is a file with extension .h which contains C function declarations and macro definitions to be shared between several source files.  Some of C Header files are: 

<stddef.h> – Defines several useful types and macros. 

<stdint.h >– Defines exact width integer types.

<stdio.h >– Defines core input and output functions.

<stdlib.h >– Defines numeric conversion functions, memory allocation.

<string.h> – Defines string handling function.

<math.h >– Defines common mathematical functions.

Syntax to include a header file in C:

                 #include<header_file_name>

3 . Main Method Declaration : The next part of a C program is to declare the main() function. 

Syntax to Declare main method:

                 int main()

                  {...}

4 . Variable Declaration : The next part of any C program is the variable declaration. It refers to the variables that are to be used in the function. In the C program, no variable can be used without being declared. Also in a C program, the variables are to be declared before any operation in the function.

Example: 

                 int main()

                {

                    int a=5;

                    . . .

                 }

5 . Body : Body of a function in C program, refers to the operations that are performed in the functions. It can be anything like manipulations, searching, sorting, printing, etc.

Example: 

                int main() 

                {

                     int a=5;

                     printf("%d",a);...

                 }

6 . Return Statement : The last part in any C program is the return statement. The return statement refers to the returning of the values from a function. This return statement and return value depend upon the return type of the function. For example, if the return type is void, then there will be no return statement. In any other case, there will be a return statement and the return value will be of the type of the specified return type.

Example:

               int main() 

                {

                      int a=5;

                      printf("%d",a);

                      return 0; 

                 }