How to use malloc for 2d array dynamic memory allocation

/*How to use malloc for 2d array dynamic memory allocation. How to write 2-d array with dynamic memory allocation */

#include<stdio.h>

#include<malloc.h>

int main()

{

int r,c,i,j;

printf("Enter No of rows and columns:");

scanf("%d%d",&r,&c);

int **array;

array=(int**)malloc(r*sizeof(int));

for(i=0;i<r;i++)

{

array[i]=malloc(c*sizeof(int));

}

Simple Program for malloc in C

How to use malloc in C. Simple Program for malloc in C.

->malloc function allocates required amount of memory in heap (instead of stack) and
returns the pointer to the address of allocated block of memory.
->We need to type cast the returned pointer by malloc as it returns a void pointer.
->memory allocated by malloc in heap is deallocated by free, so that memory in heap can be
  allocated by other malloc functions.
->Syntax of malloc in C
datatype *p;
p=(datatype *)malloc(sazeof(datatype));
example of malloc:
int *p;
p=(int *)malloc(100*sizeof(int));

Explanation:
Here, malloc function allocates 400( 100*size of integer ie 100*4=400 ) bytes in heap and
assigns the address of the allocated memory in integer pointer p.
How to use malloc in C.
Simple Program for malloc in C.
#include<stdio.h>
int main
{
int *p;
p=(int *)malloc(sizeof(int));
*p=10;
printtf("%d",*p);
free(p);
return 0;
}

Previous                             Home                               Next