initializing multidimensional array in C

Question

I am trying to initialize a multidimensional array in the following way but I am not sure if it is correct. I am re-initializing large tables implemented using multidimensional arrays and I am not sure how to do it. I need to initialize the entire row at a time and cannot initialize the elments individually.

int array[3][3];
int ind = 0;
array[ind++] = {1,2,3};
array[ind++] = {4,5,6};
array[ind++] = {7,8,9};

Ok so i cannot do something like array[3][3] = {{1,2,3},{4,5,6},{7,8,9}}; because what I actually want to do is something like this

int array[][3];
int ind = 0;
array[ind++] = {1,2,3};
if(contion1)
 array[ind++] = {4,5,6};
else 
 array[ind++] = {0,0,0};
array[ind++] = {7,8,9};

I hope this makes it more clear. This is not ideal, I know but I was handed over the code with #ifs something like this

int array[][3] = {
 {1,2,3},
 #if contion1
 {4,5,6},
 #else 
 {0,0,0},
 {7,8,9}};

and was asked to get rid of the #ifs.

• Ranic: possible duplicate of Multidimensional array initialization in C
• Igor Pejic: What do you mean get rid of the ifs? To what value do you want to set it?

Answer 1

Use the following declaration instead:

int array[3][3] = {
 {1, 2, 3},
 {4, 5, 6},
 {7, 8, 9}
 };

Answer 2

So you basically want a loop:

int num = 1;
for(i = 0 ; i < 3 ; i++)
{
 for(j = 0 ; j < 3 ; j++)
 {
 arr[i][j] = num;
 num++;
 }
}

as simple as that. You cannot initialize an array in one line - only in the first declaration. The idea of what you're saying is a loop.

Answer 3

To reinitialize you will have to use loops

for ( i = 0; i < 3; i++) {
 condition = // whatever your condition is 
 for ( n =0; n < 3; n++) {
 // if condition is zero your value is 0 non-zero condition gets the calculated value
 array[i][n] = condition ? ( i * 3) + n + 1 : 0;
 }
}