C++ Pre-Finals Exercise

Copy and Compile the following code. Explain the output. Explain the functions of each line of the code.
01 #include
02 #include
03 const int num_rows = 7;
04 const int num_columns = 5;
05
06 int
07 main()
08 {
09 int box[num_rows][num_columns];
10 int row, column;
11
12 for(row = 0; row < num_rows; row++)
13 for(column = 0; column < num_columns; column++)
14 box[row][column] = column + (row * num_columns);

15 for(row = 0; row < num_rows; row++)
16 {
17 for(column = 0; column < num_columns; column++)
18 {
19 printf("%4d", box[row][column]);
20 }
21 printf("\n");
22 }
23 getch();
24}