if() return in Update Function

Unity Engine
1

Hello people,

I couldnt figure out what this piece of code actually doing in one frame. (Especially “return”)
I just want to know, what “return” keyword doing here.

function Update()
  {
  if ( Input.touches.Length == 0 ) return;
  yellowRay = theCam.ScreenPointToRay( Input.touches[0].position );
  if ( ! collider.Raycast (yellowRay, theHit, 10.0 ) ) return;
  onTHINGPointEnd = theHit.point;
  if ( Input.touches[0].phase != TouchPhase.Moved ) return;
  startedAtGlasswise = Input.touches[0].position - Input.touches[0].deltaPosition;
  yellowRay = theCam.ScreenPointToRay( startedAtGlasswise );
  onTHINGPointBegin = onTHINGPointEnd; // our default political position
  if ( collider.Raycast (yellowRay, theHit, 10.0 ) )
  onTHINGPointBegin = theHit.point;
  if ( startedAtGlasswise.x < 0.1 * Screen.width ) return;
  if ( Input.touches[0].deltaTime == 0.0 ) return; // just in case
  moveLikeThisInRealWorld( (onTHINGPointEnd - onTHINGPointBegin) / Input.touches[0].deltaTime );
  }
function moveLikeThisInRealWorld( dd:Vector3 )
  {
  }
2

That’s very poorly formatted code but in general an empty return is just that, it escapes the rest of the conditional and returns to the normal code flow outside of the conditional.

3

Return does not escape a conditional, it escapes a function. Using it inside of the Update function will exit the Update right there, meaning nothing else in the function will run that frame. I know this might feel like nitpicking terminology, but it’s important.

You might also be interested in the break keyword, which does the same thing for a loop (for, foreach, do, do-while). That doesn’t escape a conditional either, unless you just happen to be inside of a conditional when you break the loop it’s inside of (just FYI).

It’s worth noting that a 3 second google search for “return c#” or “return javascript” would’ve brought you to the MSND Reference explaining exactly what it does. You don’t really have to post EVERYTHING on the support forum- especially not fundamental programming language stuff.

10 Likes
4

It’s a way to get out of a function early if certain conditions are not met. In this case the line says. “Stop processing if there are no touches”.

4 Likes
5

@DonLoquacious
Thanks for the answer. I really looked up forum search, google, msdn documentation, I couldnt find a plain answer like yours(Really appreciated!), at least this type of usage with unity. Hope this thread helps others like me…

Regards,

6 Likes