iterate through a 2D array returned by a function

[jessica1234]

assuming i know the length of my dynamically created 2D array, how do i iterate through it?

the array is returned from the following function.

  int ** getArray()

[gunnerfunner]

for (int i = 0; i < ROW; i++)
{
	for (int j = 0; j < COL; j++)
	{
		// typical array element is *(ary[i]+j));
		// where ary is the array 
	}
}	
//and don't forget to clean up before exit ... 
for (i = 0; i < ROW; i++) {
  delete(ary[i]);

delete [] ary; 

why this because in a pointer of pointer representation of 2D array we first allocate memory for each row starting from the first element; and then, for each row, starting from the first element we allocate memory according to the size of the columns

[Handy Andy]

Hello jessica1234,

You could try something like this:

for (int i = 0; i < firstDimensionSize; i++)
{
	for (int j = 0; j < secondDimensionSize; j++)
	{
		array[i][j]  //  i will loop through the rows and j will loop through the columns.
	}
}

You will need to expand on the code in the second for loop, but it is the basic idea.

Hope that helps,

Andy

[jessica1234]

hi andy,

first of all, how do I declare the array[][] to catch the return int** from my function?

int[][] array = getArray()

give me compilation error.

int ** getArray()

[gunnerfunner]

int** ary; 
ary = new(int* [ROW]);
for(int i = 0; i < ROW; i++)
{
	ary[i] = new int[COL];
}
//to use the array:

for (int i = 0; i < ROW; ++i) {   // for each row
  for (int j = 0; j < COL; ++j) { // for each column
    ary[i][j] = 1;
  }
}
//finally, to delete before exit:
for (int i = 0; i < ROW; i++) {
  delete[] ary[i];
}
delete[] ary;