addition in matrix in c++

Question

following is the code

for (int w=0;w<10;w++)
        {
              for( int y=0;y<8;y++)
            {
                    matrix[y][0] = arr_v1[y];
                    matrix[y][1] = arr_v2[y];
                    matrix[y][2] = arr_v3[y];
                    matrix[y][3] = arr_v4[y];
                    matrix[y][4] = arr_v5[y];
                    matrix[y][5] = arr_v6[y];
                    matrix[y][6] = arr_v7[y];
                    matrix[y][7] = arr_v8[y];
            }
            }

i want to add the values to matrix every time, for loop, for (int w=0;w<10;w++) runs. like, when w=0, it will first put values in the matrix, next time when w=1 runs, it should add values to the same matrix and so on. I am not sure, but probably something like:

int add_val=0;
        for(int c=0;c<8;c++)
        {
            for(int d=0;d<8;d++)
            {
                add_val+=matrix[c][d];
            cout<<matrix[c][d]<<" "; 
            }
            cout<<"\n";
        }

Answer 1

Init your matrix values with zeros when creating or before the loop. Then just add values in your loop

Answer 2

You can initialize all of your matrix cells to zero, then you can write something like -

for(int w=0; w<10; w++)
........
    matrix[index1][index2] += your_value;