I am trying to figure out why an old PHP code doesn't work as expected. The following line puzzles me:

Code:
$this = new $class($i!=$step);
In the above code,
Code:
$class=Step;
$i=2;
$step=2;
So does the line mean:
Code:
$this = new Step;
But there is no class Step, only Step1, Step2, etc.