Multiplication Table Error

Hello,

I am trying to make a multiplication table that goes up to 10 X 10 = 100. I am a newbie in C++ and this is probably a really stupid error.

Code:

---

  #include <iostream.h>

  int main()
  {
          int num = 1;
          int num1 = 1;
          int num2 = 2;
          int num3 = 3;
          int num4 = 4;
          int num5 = 5;
          int num6 = 6;
          int num7 = 7;
          int num8 = 8;
          int num9 = 9;
          int num10 = 10;

          do
          {
                  num1 = num++;

                  if ( num1 < 10)
                          cout << "00" << num1 << " ";
                  if ( ( num1 >= 10 ) & ( num1 < 100 ) )
                          cout << "0" << num1 << " ";
          }
          while ( num1 != 10 );

          cout << endl;


          num = 1;

          do
          {
                  num2 = num2 * num++;

                  if ( num2 < 10)
                          cout << "00" << num2 << " ";
                  if ( ( num2 >= 10 ) && ( num2 < 100 ) )
                          cout << "0" << num2 << " ";
          }
          while ( num2 != 20 );



          return 0;
  }

---

This displays alot of 000's.
Can you please explain to me what i did wrong?
Thanks in advance to all those who help me.

Are you trying to make a mult. table like 10 * 1, 10 * 2, etc. to 10 *10? If you are think about which number is changing or increasing and how much is it increasing. Then use a for statement.

Code:

---

num = 1;

do
{
    num2 = num2 * num++;
       
    if ( num2 < 10)
        cout << "00" << num2 << " ";
    if ( ( num2 >= 10 ) && ( num2 < 100 ) )
        cout << "0" << num2 << " ";
}  while ( num2 != 20 );

---

Here things go wrong.

Code:

---

num    num2    (num2 = num2 * num++)
1        2          2
2        2          4
3        4          12
4        12        48

---

So num2 will never become 20.

Hmm, you actually just need two do//while statements and two counters to solve this problem.

....
....
int num = 0;
int num1 = 0;
do
{
//Increase "left" number by one
num++;
do
{
//Increase "right" number by one
num1++;
cout << num << " * " << num1 << " = " << (num*num1) << endl;
}while ( num1 != 10 );
//When num1 has reached 10 then set it to 0 again
num1 = 0;
cout << endl;
}while ( num != 10 );
....


You can even use for-loops to achive the same result, its even better(shorter).