Question

The idea is to get all the possible combinations I can play on a 6/49 lottery.
For the first 2 numbers it works. When, I add the conditions for the third number it says: Undefined variable: b. I don’t understand why. I use echo there to check if the program is working.

Here is the code.

for ($i=1 ; $i<50 ; $i++)
{
    $a=$i;
    for ($j=1 ; $j<50 ; $j++)
    {
        if ($i!=$j)
        {
            $b=$j;  
        }
        for ($k=1 ; $k<50 ; $k++)
        {

            if ($k!=$j && $k!=$i)
            {
                $c=$k;
                echo "$a $b $c<br>";
            }
        }
    }
}

Answer 1

On the first iteration $i == $j, so $b is never initialized. You can fix it by extending the if to cover the inner loops:

for ($i=1 ; $i<50 ; $i++)
{

  $a=$i;
  for ($j=1 ; $j<50 ; $j++)
  {

    if ($i!=$j)
    {
        $b=$j;

      for ($k=1 ; $k<50 ; $k++)

      {

        if ($k!=$j && $k!=$i)
        {
            $c=$k;
            echo "$a $b $c<br>";
        }
      }
    }
  }
}