iPhone Game Having a statement checked every 50 points

Question

Hello!

I've run into a little hurdle and wanted to see if somebody could help me!

I want to write an algorithm for an if statement that says:

if (for every 50 points)
{
//do something
}

I thought += 50 would do the trick, but nope.

Any ideas?

Thanks!

Answer 1

if ((points % 50) == 0)
{
  // do something
}

Where points is an int variable containing your points. The if statement will be enterred for points 0, 50, 100, 150.. and so on

Answer 2

if (points - lastCheckpoint >= 50) 
{ 
  // do something
  lastCheckpoint = points - (points % 50);
}

Start with an int lastCheckpoint = 0; during set-up, and this'll do the trick.
Caveat: If the points increase by 100 or more between checks, the // do something will only be triggered once.
If you want it to happen for every 50 points regardless, you can change the increment statement to be lastCheckpoint += 50; although this runs the risk of the points running far ahead of lastCheckpoint.

Edit: this will be more efficient:

if (points > nextCheckpoint)
{
  // do something
  nextCheckpoint = 50 + points - (points % 50);
}

Start with int nextCheckpoint = 50; This way, the test that's performed (presumably) every iteration of the game loop doesn't include a subtraction.