Multiply a single number to a multidimensional array in C - c

Question

I'm trying to multiply a number that i choose to a multidimensional array with values that i have chose, but my code doesn't do that.
Here it is the multiplication function:
int product_array(){
i = 0;
j = 0;
int number;
int product[i][j];
printf("Insert the number\n");
scanf("%d", &number);
while (i < rows) {
printf("\n");
j = 0;
while (j < columns) {
product[i][j] = number + product[0][0] * m_array[i][j];
j++;
}
i++;
}
i = 0;
j = 0;
printf("Here it is the product\n");
while (i < rows) {
printf("\n");
j = 0;
while (j < columns) {
printf("\t%d ", product[i][j]);
j++;
}
i++;
printf("\n");
}
return product[i][j];
}
Legend: m_array means multidimensional array
Example of input ad output
Input
m_array values = 2 2 2 2
Number = 2
Output
4 4 4 4
To be clearer this is the piece of code with which the user can insert the values into the m_array:
do {
printf("How many rows will be in the array?\n");
scanf("%d", &righe);
} while (rows > Row || rows < 1);
do {
printf("How many columns will be in the array?\n");
scanf("%d", &columns);
} while (columns > Column || columns < 1);
printf("Data input\n");
while (i < rows) {
j=0;
while (j < columns) {
printf("Insert the element in the %d column and %d row\n", i, j);
scanf("%d", &m_array[i][j]);
j++;
}
i++;
}

Answer 1

Ok, so I figured out what the problem was (pretty simple), here is the code with the solution:
int product_array(){
i = 0;
j = 0;
int number;
printf("Insert the number\n");
scanf("%d", &number);
while (i < rows) {
printf("\n");
j = 0;
while (j < columns) {
m_array[i][j] = number * m_array[i][j];
j++;
}
i++;
}
i = 0;
j = 0;
printf("Here it is the product\n");
while (i < rows) {
printf("\n");
j = 0;
while (j < columns) {
printf("\t%d ", m_array[i][j]);
j++;
}
i++;
printf("\n");
}
return m_array[i][j];
}