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 pow() function in C String Handling functions in C Prime Number code in C Factorial Program in C using For Loop Factorial Program in C Using While Loop Fibonacci Series in C Using For Loop Fibonacci series in C using while loop Prime Number Program in C using for Loop While Loop in C programming examples Built-in functions in C Assert() Function C vs Java Strings Call Back Function in Embedded C Else If Ladder fgets() function Ftell() Function getc() function getch() function gets() function Heap Sort Nested if-else statement Pi() Function Positioning of file Write() function abs() function in C Attributes in C C program to find factorial of a number using Recursion Ferror() in c fopen() function in C Fibonacci series program in C using Recursion Formatted Input and output function in C Snake Game in C User Defined Functions in C Beep() function in C Cbrt() function in C Hook() function in C Isalnum() function in C C Program to find the Roots of a Quadratic Equation C Switch Statements Difference between rand() and srand() function in C Difference between while and for loop in C Doubly Linked list in C Example of Iteration in C How to use atoi() function in C How to use floor() function in C How to use sine() function in C How to use Typedef Struct in C Integer Promotions in C C Program Swap Numbers in cyclic order Using Call by Reference C Program to Find Largest Number Using Dynamic Memory Allocation C Program to Find the Largest Number using Ternary Operator C/C++ Program to Find the Size of int, float, double and char Find the Largest Three Distinct Elements in an Array using C/C++ Loop Questions in C Modulus on Negative Numbers in C Multiplication table program in C using For loop Nested Loops in C Programming Examples C Program for Mean and Median of an Unsorted Array Results of Comparison Operations in C and C++ Reverse a Stack using Recursion in C Simple hash() function in C strcat() Function in C Sum of N numbers in C using For loop Use of free() function in C Write a program that produces different results in C and C++ C Function Argument and Return Values Keywords in C Bank management system in C Calendar application in C Floor() Function in C Free() Function in C How to delete a file in C How to move a text in C Remove an element from an array in C Unformatted input() and output() function in C What are linker and loader in C SJF Scheduling Program in C Socket Programming in C Structure in C Tower of Hanoi in C Union Program in C Variable Declaration in C What is Linked List in C While Loop Syntax in C fork() in C GCD program in C Branching Statements in C Comma Operator in C Control statement in C Double Specifier in C How to create a binary file in C Long int in C Palindrome Number in C Pure Virtual Function in C Run Time Polymorphism in C Types of Array in C Types of Function in C What is a buffer in C What is required in each C Program Associativity of Operators in C Bit Stuffing Program in C Actual and Formal Parameters Addition of two Numbers in C Advantages of function in C Arithmetic Progression Program in C Binomial Coefficient Program in C Difference between Array and List in C Diffie-Hellman Algorithm in C How to convert a number to words in C How to convert a string to hexadecimal in C Difference between If and Switch Statement in C C and C++ Binary Files C program that does not Suspend when Ctrl+Z is Pressed Different ways to Declare the Variable as Constant in C Range of Int in C C Program to find the size of a File FIFO Example in the C Language For loop in C Programming GCD program of two numbers in C GPA Calculator in C How to Calculate Time Complexity in C How to include graphics.h in C How to measure time taken by a function in C How to return a Pointer from a Function in C What is the main in C Addition of Matrix in C Booleans in C C Program for Extended Euclidean algorithms C Program of Fencing the Ground Ceil and Floor in C Compound Interest Program in C Displaying Array in C Distance Vector Routing Protocol Program in c Dos.h Header File in C Language DSA Program in C Explain the two-way selection in C Fee Management System in C File Operations in C Malloc function in C Multiplication Table in C Simple Programs in C Language tolower() Function in C Type Conversion in the C Why does sizeof(x++) not Increment x in C Advantages of Dynamic Memory Allocation in C Armstrong Number in C Assignment Operator Program in C Banker’s Algorithm in C Binary Search in C with Best and Worst Time Complexity Caesar Cipher Program in C Call by Value and Call by Reference in C Conditional Operator in C CRC Program in C Deadlock Detection Program in C Decimal to Binary in C Difference between If Else and Nested If Else in C Difference between Pre-increment and Post-increment in C Difference between Scope and Lifetime in C Evaluation of Arithmetic Expression in C Explain the Increment and Decrement Operators in C Fseek Function in C Functions in C How to Find Square Free Numbers in C Length of an Array Function in C OpenGL in C Projects on C language in 2023 Purpose of a Function Prototype in C Stdio.h in C Two-Dimensional array in C What is String Comparison in C C Compilers for Windows Functions and Recursion in C How to Declare Boolean in C How to Declare Character in C How to Round up a number in C How to use strlen() in C Pointer Declaration in C Algorithm for String Palindrome in C C Program to find ASCII value of a character Constant Pointer in C How to find string length in C using strlen() function Implicit and Explicit in C Indirect Recursion in C Input and Output functions in C isupper() in C Jump Statement in C Lifetime of a Variable in C Linker Error in C Language Numeric Constant in C Size of Pointer in C Square Root in C Language Static and Dynamic Memory allocation String Declaration in C Strong Number in C Symmetric Matrix in C Types of C Tokens What is a Size of Pointer in C What is Increment and Decrement Operator in C 1 2 3 4 Series Program in C Advantages and Disadvantages of C Language C Program for Polynomial Addition C Program to Count the Number of Vowels in a String C Programming Errors and Solutions Compilation Errors in C Complex C Programs Difference between Argument and Parameter in C Difference between char s[] and char *s in C Evaluation of Postfix Expression Using Stack in C Find Leftmost and Rightmost Set Bit of a Number fprintf and fscanf in C Introduction to Dynamic Array in C Print Address in C Realloc function in C Ternary Operators in C Types of Tokens in C with Examples Difference between Static and Dynamic Memory Allocation in C Addition Program in C Array Definition in C Array of Pointers in C Arrow Operator in C Average of Two Numbers in C Binary to Decimal in C Binary to Octal in C BREAK STATEMENT in C C Programming Operators Questions C Programs Asked in Interview Calculator Program in C C Program to Read and Print an Employee's Detail Using Structure Bubble Sort Algorithm in C C Program to Find Area and Perimeter of Circle C Program to Check Whether a Given Number is Even or Odd C in Roman Numerals C Program to Make a Simple Calculator Using Switch Case Insertion Sort Program in C How to take input in string in C GCC Conflicting Types in C Function Definition in C Format Specifier for Hexadecimal in C Flowchart in C Float in C Fizzbuzz Implementation in C Conditional Statement in C Conio.h functions list in C Constants in C Dynamic Array in C Decision Making Statements in C Continue Statement in C Creation of Thread in C DFS Algorithm in C Difference between parameter and arguments in C Dijkstra's Algorithm in C Leap Year Program in C Jump Statements in C Modulus Operator in C Memory Allocation in C Simple Interest Program in C Reverse Array in C Recursive Function in C Queue in C Printing Pascal’s Triangle in C Preprocessor Directives in C Perror() in C Perfect Number in C Programming Language Parameter Passing Techniques in C Pascal Triangle in C Patterm Program in C Diagonal Matrix in C Converting Dollars into Rupees in C Typedef Function Pointer in C Unsigned Char in C C Program to Calculate Percentage C Program to Find Sum of Array Elements Clock Program in C How to reverse a number in C? Insert Array in C Kbhit() Function in C Can We Learn Python Without C? C program to convert decimal to hexadecimal C program to draw a circle C Program to Calculate Electricity Bill C program for string concatenation C program to convert decimal to binary without using array Graphics Programming in C File Handling Functions in C Convert Char to Int in C Identifiers In C ftok() function in C Dangling else program in C DFS Program in C Ifdef in C How to initialise an array in c Implementation of queue using Array in C Selection Statements in C Size of Char in C Strchr() function in C Symbolic Constants in C Tree Data Structure in C Type Conversion in C Types of Constants in C Void data type in C Argument in C Bitwise Operator in C Circular queue in C COMPILER IN C ctype h in c execvp() function in C Exit function in C Hashing in C How to define a global variable in C

Malloc function in C

When the user or programmer does not know how much memory space is needed in the application, it a needs dynamic memory allocation during runtime.

Dynamic memory allocation helps us to use memory efficiently by enabling us to allocate Memory continuously during runtime rather than in advance. This makes us use the memory space effectively and helps us stay in Memory.

The predefined library function known as Malloc standsfor memory allocation.

When a program runs, Malloc is used to allocate a memory block of a specific size.

The characteristics of the Malloc () function allow us to allocate Memory at some point during runtime. These characteristics are defined inside the header.

The characteristic requires a length in bytes as input and, upon successful memory allocation, provides a void pointer that may be cast to any other kind.

The C malloc() function provides a void type pointer, allowing us to assign dynamic Memory for any data type (primitive or user-defined). A NULL pointer will be returned if the minimum amount of memory space is not available.

Syntax of Malloc () Function in C

ptr = ( cast_ type *) malloc (byte_size);  

Return Value of Malloc () Function in C

The C language's Malloc function only allocates one memory block at a time, and the assigned memory address carries the initial garbage cost.

A void pointer corresponding to the Memory allocated by the C malloc function is the return value or type of the Malloc () function in C. The advantage of using a void pointer as the return type is that it allows us to do this for any data type pointer.

Parameters of Malloc() function

The number of bytes of Memory that will be allocated is the sole argument required by the C language's Malloc function. Because the size of each data type might vary depending on the compiler, the sizeof() method is typically used to determine how many bytes are needed.

Free():-

The Memory allotted during runtime does not automatically release itself. Memory allocated at runtime can be manually released using the free() function.

The same header has a description for the free() function. The attribute accepts a pointer and releases the Memory that is pointing to the reference.

Dynamic Memory, often known as heap memory, is the Memory that is allocated to variables when the C programming language's malloc() or calloc() operations are used.

When a programmer defines a variable for a primitive or user-defined data type, static Memory or stack memory is allotted to it.

A program to check if memory is created using the Malloc () function.

#include <stdio.h>  
#include <stdlib.h>  
int main ()  
{  
    // declare a pointer of type int //
    int *pt; 
    // use the Malloc () function to define the size of the block in bytes  
    pt = malloc (sizeof(int));  
      
    // use if the condition that defines ptr is not equal to null  
    if (pt != NULL)  
    {  
        printf ( " Memory is created using the malloc() function ");  
    }  
    else  
    {
    printf ( " memory is not created ");
    }
    return 0;     
}   

OUTPUT

Malloc function in C

Program to create a dynamic memory using the Malloc () function

#include <stdio.h>  
#include <stdlib.h>   
int main ()  
{  
    // declare the local variables  //
    int *ptr, size, i;  
      
    printf (" Enter the allocated size of memory ");  
    scanf (" %d", &size);     
    // use the Malloc () function to define the size of the block in bytes // 
    ptr = malloc (size * sizeof(int));    
    // use if the condition that defines ptr is not equal to null //  
    if (ptr != NULL)  
    {  
        // get input from the user and print it  //
        printf (" Enter numbers from the user: ");        
        for ( i = 0; i < size; i++)  
        {  
            scanf (" %d", ptr + i); 
     // stores the numbers from base address of memory  //
        }         
        printf (" Numbers are stores in contiguous memory: \n ");         
        for ( i = 0; i < size; i++)  
        {  
            printf (" \n The number is: %d", *(ptr + i)); 
          // here *(ptr + i) is same as ptr[i]  
        }  
        printf (" \n Memory is created using the malloc() function ");  
        return 0;  
    }  
    else  
    printf (" memory is not created ");  
    return 0;  
}  

OUTPUT

Malloc function in C

free() function program using Malloc()

#include <stdio.h>
#include <stdlib.h> 
int main()
{
   int* ptr; 
   ptr = (int*)malloc(5* sizeof(int)); 
   if (ptr==NULL)
   {
         printf( "Memory not allocated \n"); 
   }
 else 
  {
      printf( "Memory allocated successfully \n ");
      for (int i=0; i<5; i++) 
      {
         ptr[i]=i; 
      }
      printf("The elements of the •array are: "); 
      for (int i=0; i<5; i++) 
      {
         printf("%d \n", ptr[i]); 
      }
  }
 free(ptr);
 return 0; 
}

OUTPUT

Malloc function in C

free() function program using Calloc()

#include <stdio.h>
#include <stdlib.h> 
int main()
{
   int* ptr; 
   int n;
   printf(" Enter the elements you want ");
   scanf("%d",&n);
   ptr = (int*)calloc(n, sizeof(int)); 
   if (ptr==NULL)
   {
         printf( "Memory not allocated \n"); 
   }
 else 
  {
      printf( "Memory allocated successfully \n ");
      printf(" Enter the values ");
      for (int i=0; i<5; i++) 
      {
         scanf("%d" ,&ptr[i]); 
      }
      printf("The elements of the •array are: "); 
      for (int i=0; i<5; i++) 
      {
         printf("%d \n", ptr[i]); 
      }
  }
 free(ptr);
 return 0; 
}

OUTPUT

Malloc function in C