Method: Not all code paths return a value

Question

Ok so while working on an XNA 4.0 game I'm developing I came across this problem with one of my methods which is getting the error 'not all code paths return a value' and well this has been driving me insane for the past couple hours.

 private Rectangle HandleCollision(Rectangle bounds, TileCollision collision, Rectangle tileBounds)
    {
        Vector2 depth = RectangleExtensions.GetIntersectionDepth(bounds, tileBounds);
        if (depth != Vector2.Zero)
        {
            float absDepthX = Math.Abs(depth.X);
            float absDepthY = Math.Abs(depth.Y);

            // Resolve the collision along the shallow axis.  
            if (absDepthY < absDepthX || collision == TileCollision.Platform)
            {
                // If we crossed the top of a tile, we are on the ground.
                // also ladder
                if (previousBottom <= tileBounds.Top)
                {
                    if (collision == TileCollision.Ladder)
                    {
                        if (!isClimbing && !isJumping)
                        {
                            //walking over a ladder
                            isOnGround = true;
                        }
                    }
                    else
                    {
                        isOnGround = true;
                        isClimbing = false;
                        isJumping = false;
                    }
                }


                // Ignore platforms, unless we are on the ground.  
                if (collision == TileCollision.Impassable || IsOnGround)
                {
                    // Resolve the collision along the Y axis.  
                    Position = new Vector2(Position.X, Position.Y + depth.Y);

                    // Perform further collisions with the new bounds.  
                    bounds = BoundingRectangle;
                }
            }
            else if (collision == TileCollision.Impassable) // Ignore platforms.  
            {
                // Resolve the collision along the X axis.  
                Position = new Vector2(Position.X + depth.X, Position.Y);

                // Perform further collisions with the new bounds.  
                bounds = BoundingRectangle;
            }

            else if (collision == TileCollision.Ladder && !isClimbing)
            {
                //stops colliding with ladder if player walks past or drops off ladder
                Position = new Vector2(Position.X, Position.Y);

                //perform collisions with new bounds
                bounds = BoundingRectangle;
            }
            return bounds;
        }
    }

Any help understanding this error would be appreciated, thanks.

Your return statement is inside an if block - any code which will not enter that if block will not return anything but your method requires to return a Rectangle type. Having the return statement outside the if block should resolve the issue. — Satyajit, Mar 07 '13 at 20:20
return bounds; is inside your main if statement. is there a default value you can return? either way, you need to return something outside of your if statement, in case it never makes it to the return bounds; line. maybe create bound before the if, set it to null, and return after the if statement. — mmeasor, Mar 07 '13 at 20:21

score 3 · Answer 1 · answered Mar 07 '13 at 20:18

3

Your issue is here.

if (depth != Vector2.Zero)

if this evaluates to false, nothing gets returned.

answered Mar 07 '13 at 20:18

scartag

17,548
3
48
52

score 0 · Answer 2 · answered Mar 07 '13 at 20:18

0

Move your return bounds; statement outside the if statement. If that if statement resolves to false then the return is never hit.

answered Mar 07 '13 at 20:18

Justin Chmura

1,939
1
15
17

Thanks a lot this worked, cant believe it was that simple I feel like a complete idiot now.. – Kyle Mar 07 '13 at 20:29

score 0 · Answer 3 · answered Mar 07 '13 at 20:19

0

If depth is equal to Vector2.Zero you don't return anything. Hence, not all code paths return a value.

answered Mar 07 '13 at 20:19

Roman Royter

1,655
13
28

Soner Gönül · Answer 4 · 2013-03-07T20:27:46.010

0

What if your depth != Vector2.Zero return false in

if ( depth != Vector2.Zero )

condition?

Your method doesn't return anything at this point. You must return value also outside of this loop.

edited Mar 07 '13 at 20:27

answered Mar 07 '13 at 20:19

Soner Gönül

97,193
102
206
364

score 0 · Answer 5 · answered Mar 07 '13 at 20:20

0

The return statement is nested inside of your conditional. So if (depth == Vector2.Zero) the method will not return a value.

answered Mar 07 '13 at 20:20

smedge

1

score 0 · Answer 6 · answered Mar 07 '13 at 20:21

0

it's because if you first IF would return false then as the error says Not all code paths return a value. you should consider adding a return value or may be an exception for that case

answered Mar 07 '13 at 20:21

Arash Milani

6,149
2
41
47

score 0 · Answer 7 · answered Mar 07 '13 at 20:22

You need to move your final return value outside of your if:

private Rectangle HandleCollision(Rectangle bounds, TileCollision collision, Rectangle tileBounds)
{
  if(depth != Vector2.Zero)
  {

  }
  return bounds;
}

you have it like this:

private Rectangle HandleCollision(Rectangle bounds, TileCollision collision, Rectangle tileBounds)
{
  if(depth != Vector2.Zero)
  {
     return bounds;
  }
}

What this means, is if depth == Vector2.Zero nothing gets returned, so you get the error that you are seeing.

Method: Not all code paths return a value

7 Answers7