C Tutorial

C Tutorial C Language Environment Setup Execution flow of C program C printf and Scanf C Data type C Token Variable in C Operators in C Comments in C Escape Sequence in C C – Storage Classes C Decision control statement Loop Statement in C Break, continue and goto statement in C Type Casting in C Function in C Recursion in C String in C C Array Pointer in C Dynamic memory allocation C –Structure Nested Structure in C Union in C File Handling in C C pre-processor Static Function In C Sizeof In C Selection Sort In C Scope Of Variables In C Runtime Vs Compile Time In C Random Access Lseek In C Queue Implementation In C Pseudo Code In C Prototype In C Pointer To Pointer In C Pointer Arithmetic In C Passing Array To Function In C Null Character In C Merge Sort In C Macros In C Library Functions In C Memory Leak In C Int In C Goto And Labels In C Fibonacci Series In C Fflush In C Derived Data Types In C Data Types In C Const Vs Volatile In C Character Set In C Character Class Tests In C Calloc In C C Pointers Arrays In C Include In C Clrscr In C C Vs Java String Literals In C Types Of Pointers In C Variables In C Volatile In C Why C Is A Middle Level Language Infix To Postfix Program In C Ceil function in C LCM of two numbers in C Quick sort in C Static in C function pointer as argument in C Top Array Keywords in C Add two numbers using the function in C Armstrong program in C using function Array, Declaring Arrays and Array Initialization Limitations of Inline Function in C Merge and Merge sort with example in C Do-While Loop in C For Loop in C While-Loop in C Difference between while and do-while loop in C Array Of Structures in C Data Structures And Algorithms in C Types Of Structures In C How to Avoid Structure Padding in C Use of Structure in C Do WHILE LOOP in C Programming Examples For Loop in C Programming Examples Entry Control Loop in C Exit control loop in C Infinite loop in C Nested loop in C

Why C is a middle level language

The C programming language is generally referred to as a high level language but we glance through the backend of C, i.e the working of C as a programming language we find that it’s in between a high level language and a low level language.That’s why we use the term middle level language. This term (a middle level language) is used in the context of C, because it acts as a binding force to bridge the gap between high level programming language and low level programming language. Here it is referred to as bridge because C provides features of both high level and low level language.

Note: Middle level languages are closely related to low level language as well as high level language.

The application of C programming language is very wide, it used to write both system software and application software. This classification of C into a middle level language is done because of the following reasons. Or we can say the following features makes the C programming language as a middle level language :

  1. Support for Inline Assembly Language Programs - The C Programming Supports Inline Assembly Language Programs .
  1. The Use of inline assembly language features in C allows direct access to system registers.
  1. Access to memory - The language  is used to access memory directly using a pointer. This feature is absent in high level languages like Java.
  1. C is considered more user friendly compared to former or similar middle level languages.

The C preprocessor

The C preprocessor can be defined as a macro processor that is used automatically by the C compiler to convert your C program before the actual compilation. In simple terms, a C preprocessor is a means of medium which provides certain language facilities.

One thing every programmer should understand here is that the C preprocessor is not a part of the compiler. It may be referred to as a step in the compilation  process(conceptually a separate first part).

Note:  The preprocessor can be referred to as a text substitution tool which instructs the compiler to perform the required actions( pre-processing) before the actual compilation.

Program 1:  #include and #define preprocessor to, Calculate the Area of Circle

#include <stdio.h>
#define PI 3.14
int main()
{
    float radius, area;  // declaring the local variables
    printf("Enter the radius: ");
    scanf("%f", &radius); // user input: to get the radius 


    
    area = PI*radius*radius; // using the declaration PI


    printf("Area=%.2f",area); // prints area of circle
    return 0;
}

Dynamic Memory Allocation using malloc()

The malloc() stands for memory allocation and it is a built-in function which is declared inside the <stdlib.h>. Here, the <stdlib.h> indicated a header file in C.

The malloc function or malloc() is used to dynamically allocate memory. In simple terms, the malloc function will dynamically allocate a single block of memory which will be contiguous (one after another) in nature and will be of size as specified by the programmer.

Declaration

(void* ) malloc(size_t size)

Here, size_t is defined in <stdlib.h> as unsigned int.

Note 1: The malloc function will simply allocate a block of memory as specified in the heap and if it is successful, it returns a pointer which points to the first byte of the allocated memory. In case of failure, NULL is returned.

Note 2: The malloc returns a void pointer on successful memory allocation.

Why Void Pointer?

The malloc function returns a void pointer on successful allocation of memory because the malloc() is not aware of the location it is pointing to. This function simply provides the memory block requested by the programmer without the acknowledgment of data to be stored inside the memory.

Although, the void pointer can be type casted to an appropriate type.

Conclusion

This term (a middle level language) is used in the context of C, because it acts as a binding force to bridge the gap between high level programming language and low-level programming language. Middle level languages are closely related to low level language as well as high level language.

The application of C programming language is very wide, it used to write both system software and application software.

  1. Support for Inline Assembly Language Programs - The C Programming Supports Inline Assembly Language Programs.
  1. The Use of inline assembly language features in C allows direct access to system registers.
  1. Access to memory - The language is used to access memory directly using a pointer. This feature is absent in high level languages like Java.
  1. C is considered more user friendly compared to former or similar middle level languages.



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