vidhya165

 Profile Answers by vidhya165 Questions by vidhya165

• Feb 4th, 2006

 

dynamic initialization of double dimensional arrays:

int num[rows,cols] = {row1col1, row1col2, row1col3.......row2col1, row2col2, row2col3,..........row3col1, row3col2, row3col3, ..........rowncoln};

hope this is clear.

vidhya165

 Profile Answers by vidhya165 Questions by vidhya165

• Feb 5th, 2006

 

example of how to dynamically initialize double dimensional arrays:

int num[2][3] = {34,32,30,24,22,20};

num[1][1] = 34

num[1][2] = 32

num[1][3] = 30

num[2][1] = 24

num[2][2] = 22

num[2][3] = 20

vasanth

• Mar 1st, 2006

 

I think you told it for static declaration and not for dynamic. please make me clear between static and dynamic

Dharmarajan V .[Programmer]

• Mar 2nd, 2006

 

    main()

   {

     int m,n;

     cin>>m>>n;

     int a[m][n];

    }

mansoor

• Mar 7th, 2006

 

it is wrog...! beczuse u can not use cariable while definig array size..!!

it can be done by using malloc() function..! i just dont remember exact coding but it look like that.

int size;cin>>size

int *array;

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

its is for single dimension array...but its not exact code for it..

saisreelu

 Profile Answers by saisreelu 

• Mar 8th, 2006

 

U can assign the memory dynamically for a 1 dimensional array in the following way:

int *a;

int i; //Can be any value

a = (int *)malloc (i * sizeof(int));

Dynamic allocation of arrays of more than one dimension is not so easily done, because dynamic allocation of an n-dimensional array actually requires dynamic allocation of n 1-dimensional arrays. To allocate a 2-dimensional array you must first allocate memory sufficient to hold all the elements of the array (the data), then allocate memory for pointers to each row of the array. For arrays of more than two dimensions it gets more complicated.

Richa Yadav

• Mar 12th, 2006

 

#includeint **arr = malloc(rows * sizeof(int)); for (i=0; i

paulson paul chambakottukudyil

• Apr 12th, 2006

 

If you use calloc(m,n) for allocating the memory, all of them will be initialized with zeros.

Soundari

• Apr 25th, 2006

 

We can use the following code to allocate memory for a double dimensional array of R rows and C columns.

int ** ppIntArr = NULL;

ppIntArr = (int**) malloc(R * sizeof(int**));

for(int i = 0; i < R; i++)

{

ppIntArr[i] = (int*) malloc(C * sizeof(int*)); 

}

binnoor

• Jul 20th, 2006

 

I think this can be done like that 

int ** p = 0;
 
 p = new int * [nRows];

 for(int i = 0 ; i < nRows ;i++)
 {
  p[i] = new int [nCols];
 }

// release memory

 for(i = 0 ; i < nRows ;i++)
 {
  delete [] p[i];

 }
 delete [] p;

Harsh Nanchahal

• Aug 18th, 2006

 

It has been written in c++ that no array allocated dynamially be initialized.So there has to be a zero argument constructor for that class.

SomGollakota

 Profile Answers by SomGollakota 

• Jun 13th, 2007

 

If the question is "How to initialize memory that is dynamically allocated for a 2D array", there are a couple different ways.

1. Use memset. memset sets a chunk of memory to a given value. Ultimately, 1D or 2D, memory is memory.
2. Run a two dimentional loop
    for(int i = 0; i < 10; i++)
         for( int j = 0; j < 20; arr[i][j++] = ' ');

I may be a little off with the syntax, but hope you get the idea.
                    

Ajay Kanse

 Profile Answers by Ajay Kanse Questions by Ajay Kanse

• Dec 23rd, 2008

 

There are multiple ways to do this :
1. int **arr = (int**) malloc(nrows * sizeof(int*));
    for (i=0 ; i<nrows ; i++)
    {
       arr[i]=(int*) malloc (ncols * sizeof(int));
    }

2. int **arr = (int *) malloc (nrows*ncols*sizeof(int));

nrow are number of rows and nclos are number of columns.