num and numDist can be integer constants, or integer variables. Floating-point values are obviously illegal; creating 500.01 circles is meaningless. Using a floating-point constant or variable will cause a crash. Leaving out a parameter causes a run-time crash.

createCircles() creates num circles, plus or minus numDist circles. All attributes that are currently active are applied to all circles created. If you want the same number of lines created every time, numDist should be zero. Otherwise, you'll end up with somewhere between (num + numDist) and (num - numDist) circles.