INTRODUCTION TO C

C Language Introduction

C is a procedural programming language. It was initially developed by Dennis Ritchie between 1969 and 1973. It was mainly developed as a system programming language to write operating system. The main features of C language include low-level access to memory, simple set of keywords, and clean style, these features make C language suitable for system programming like 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 is mainly based on C language. C++ is nearly a superset of C language (There are few programs that may compile in C, but not in C++).

Beginning with C programming:

1. Structure of a C program
   After the above discussion, we can formally assess the structure of a C program. By structure, it is meant that any program can be written in this structure only. Writing a C program in any other structure will hence lead to a Compilation Error.
   The structure of a C program is as follows:

The components of the above structure are:

1. Header Files Inclusion: The first and foremost 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:
   • 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, pseudo-random network generator, memory allocation
   • string.h – Defines string handling functions
   • math.h – Defines common mathematical functions
   Syntax to include a header file in C:

   #include <(header_file_name).h>
   

2. Main Method Declaration: The next part of a C program is to declare the main() function. The syntax to declare the main function is:
   Syntax to Declare main method:

   int main()
   {}
   

3. 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. Please note that in 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;
   .
   .
   

4. 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;
   
       printf("%d", a);
   .
   .
   

5. 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;
   
       printf("%d", a);
   
       return 0;
   }

Note:-Don't worry about it if you could not get some part , i will cover every

thing in details in the future posts.