1-10/1-12??

[atjm88]

#include <iostream>
#include <iomanip>
#include <conio>

int main()
{
   int j;
   cout<<"\n\t Multiplication Tables";
   cout<<"\n _____________________________________\n\n";

   for(int n=1; n<=12; n++)
   {

      while(j<=10)
      {
      	cout<<setw(4)<<j*n;
         j++;
      }
      cout<<endl;
   }

   cout<<"\n\tEnd Of Program";
   getch();
   return 0;
}

Can I know why the above program get 1-10? Which command do that? I guess it shud get 1-12 right? TQ...

[MrHutch]

First of all, you may want to initialise j.

Otherwise there's no real telling what's going on in that while loop. Assuming you initialised j to 0, that while loop will only ever run once because you don't reset j anywhere.

What is it you're trying to do, exactly?

Print out the 12 times table for value j?

[atjm88]

Yes...This is the real code...

#include <iostream>
#include <iomanip>
#include <conio>

int main()
{
	int j;
   cout<<"\n\t Multiplication Tables";
   cout<<"\n _____________________________________\n\n";

   for(int n=1; n<=12; n++)
   {
      j=1;
      while(j<=10)
      {
      	cout<<setw(4)<<j*n;
         j++;
      }
      cout<<endl;
   }

   cout<<"\n\tEnd Of Program";
   getch();
   return 0;
}

I know that if I don't initialize the j, the while loop should not work, but then why still have value 1-12 in output? TQ...

[MrHutch]

It seems right for what it's doing to me.

When I run it, it prints out a multiplication table correctly.

12 rows and 10 columns, which is what's specified.

Look at what you're effectively saying:

- First iteration of loop, n=1:
- Set j to 1.
- For all values of j between 1 to 10, print 1 * j.
- Print an endline
- Second iteration of loop, n=2:
- Set j to 1.
- For all values of j between 1 to 10, print 2 * j.

And so on. All the way up to and including n=12.

Functionally, this is fine. What are you expecting it to do?

[atjm88]

Actually just now I'm trying to change the inner loop to "for loop" and outer loop to "while loop" but accidently deleted j=1; in line 13, then i compile the program and get the value 0-10 (which I don't know where it comes from)...

but if I deleted the whole while loop(code below), the ouput doesn't shows any value instead of the cout things only...which is true...(meaning that if got while loop but no initialize j=1, the ouput is 0-10<-which I don't know why since while loop is not execute at all if no initialize j right? But there is still a output... This is my question...TQ...)

#include <iostream>
#include <iomanip>
#include <conio>

int main()
{
	int j;
   cout<<"\n\t Multiplication Tables";
   cout<<"\n _____________________________________\n\n";

   for(int n=1; n<=12; n++)
   {


      cout<<endl;
   }

   cout<<"\n\tEnd Of Program";
   getch();
   return 0;
}