Coding problem ("Expected identifier or '(' before 'if'")

[Ubermatik]

Hello,

First off, I'm new here (as you may be able to tell!) so I'm sorry if this is the wrong section...

I have a problem and was wondering if you could help me: I'm following a tutorial at the moment, which involves building a simple Pong-style game. I've followed it letter for letter (apart form the fact I have changed the names of a few objects etc.), but have come across a problem - it's an error that reads: "Expected identifier or '(' before 'if'.
Do you have a solution to the problem, or know of a way in which I could solve it? I'm really eager to become familiar with the SDK, so I'd love to know what the problem is too. Thanks in advance! (the problem line is highlighted in red) (the tutorial is here, if needed)

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];
	self.gameState = kGameStatePaused;
	pucVelocity = CGPointMake(kPucSpeedX,KPucSpeedY);
	[NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:@selector(gameLoop) userInfo:nil repeats:YES];
}

-(void) gameLoop {
	if(gameState == kGameStateRunning) {
		
		puc.center = CGPointMake(puc.center.x + pucVelocity.x , puc.center.y + pucVelocity.y);
		
		if(puc.center.x > self.view.bounds.size.width || puc.center.x < 0) {
			pucVelocity.x = -pucVelocity.x;
		}
		
		if(puc.center.y > self.view.bounds.size.height || puc.center.y < 0) {
			pucVelocity.y = -pucVelocity.y;
		}
	} else {
		if (tapToBegin.hidden) {
			tapToBegin.hidden = NO;
		}
	}
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
	if (gameState == kGameStatePaused) {
		tapToBegin.hidden = YES;
		gameState = kGameStateRunning;
	} else if(gameState == kGameStateRunning) {
		[self touchesMoved:touches withEvent:event];
	}
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
	UITouch *touch = [[event allTouches] anyObject];
	CGPoint location = [touch locationInView:touch.view];
	CGPoint xLocation = CGPointMake(location.x,paddleblue.center.y);
	paddleblue.center = xLocation;
}

if (CGRectIntersectsRect(puc.frame,paddleblue.frame)) {
	if(puc.center.y < paddleblue.center.y) {
		pucVelocity.y = -pucVelocity.y;
		NSLog(@"%f %f",puc.center,paddlegreen.center);
	}
}

if (CGRectIntersectsRect(puc.frame,paddlegreen.frame)) {
	if(puc.center.y > paddlegreen.center.y) {
		pucVelocity.y = -pucVelocity.y;
	}
}

//AI
if (puc.center.y <= self.view.center.y) {
	if(puc.center.x < paddlegreen.center.x) {
		CGPoint compLocation = CGPointMake(paddlegreen.center.x - kCompMoveSpeed, paddlegreen.center.y);
		paddlegreen.center = compLocation;
	}
	
	if(puc.center.x > paddlegreen.center.x) {
		CGPoint compLocation = CGPoint(paddlegreen.center.x + kCompMoveSpeed, paddlegreen.center.y);
		paddlegreen.center = compLocation;
	}
}

[Trisect Development]

Try moving the close bracket

	paddleblue.center = xLocation;
} <==== Try to move this

if (CGRectIn

[Ubermatik]

Unfortunately that doesn't work - the 3 errors still appear, and it takes quite a while (longer than usual) to compile...

[Paul10]

Your if conditions are just kinda floating out there...If thats a class, then they should reside within a method.

My guess, without looking at the tutorial, is that your if's should be moved to the touchesMoved method.

[Ubermatik]

I'm very new to all this - hence why I'm following a tutorial. Could you elaborate? Should they be included within the - (void) touchesMoved part, instead of just below it?

[Paul10]

I'd try just moving your If conditions inside the touchesMoved code. That should fix your errors...now, if its what the tutorial wanted, I dont know

[Paul10]

Ok, I took a glance at the tutorial. It looks like for your IF's, it wanted to you to put them "inside" the gameloop method.

"Inside the gameLoop method of iTennisViewController.m add the following code"

[Ubermatik]

Okay... how would I go about doing that? Do I simply indent all my code so it's beneath the touchesMoved code? Or should I get rid of all the {/}'s?

[Paul10]

Originally Posted by Ubermatik

Okay... how would I go about doing that? Do I simply indent all my code so it's beneath the touchesMoved code? Or should I get rid of all the {/}'s?

You'd just cut them from their location and put them inside the gameloop..so gameloop would be:

-(void) gameLoop {
	if(gameState == kGameStateRunning) {
		
		puc.center = CGPointMake(puc.center.x + pucVelocity.x , puc.center.y + pucVelocity.y);
		
		if(puc.center.x > self.view.bounds.size.width || puc.center.x < 0) {
			pucVelocity.x = -pucVelocity.x;
		}
		
		if(puc.center.y > self.view.bounds.size.height || puc.center.y < 0) {
			pucVelocity.y = -pucVelocity.y;
		}
	} else {
		if (tapToBegin.hidden) {
			tapToBegin.hidden = NO;
		}
	}

	if (CGRectIntersectsRect(puc.frame,paddleblue.frame)) {
		if(puc.center.y < paddleblue.center.y) {
			pucVelocity.y = -pucVelocity.y;
			NSLog(@"%f %f",puc.center,paddlegreen.center);
		}
	}

	if (CGRectIntersectsRect(puc.frame,paddlegreen.frame)) {
		if(puc.center.y > paddlegreen.center.y) {
			pucVelocity.y = -pucVelocity.y;
		}
	}

	//AI
	if (puc.center.y <= self.view.center.y) {
		if(puc.center.x < paddlegreen.center.x) {
			CGPoint compLocation = CGPointMake(paddlegreen.center.x - kCompMoveSpeed, paddlegreen.center.y);
			paddlegreen.center = compLocation;
		}
	
		if(puc.center.x > paddlegreen.center.x) {
			CGPoint compLocation = CGPoint(paddlegreen.center.x + kCompMoveSpeed, paddlegreen.center.y);
			paddlegreen.center = compLocation;
		}
	}

} //End of gameloop

[Ubermatik]

Okay, that rids the 3 original errors - but now I get a new error:

//AI
	if (puc.center.y <= self.view.center.y) {
		if(puc.center.x < paddlegreen.center.x) {
			CGPoint compLocation = CGPointMake(paddlegreen.center.x - kCompMoveSpeed, paddlegreen.center.y);
			paddlegreen.center = compLocation;
		}
		
		if(puc.center.x > paddlegreen.center.x) {
			CGPoint compLocation = CGPoint(paddlegreen.center.x + kCompMoveSpeed, paddlegreen.center.y);
			paddlegreen.center = compLocation;
		} 
	}
}

At the highlighted line, I get the message "Expected expression before CGPoint". Any ideas? Thanks for your patience.

[Paul10]

Look at the similar line above...it looks like you have CGPoint where you should have CGPointMake.

[Ubermatik]

Ah! Thanks for spotting that! It would have been a pain to find later on, when I realised the game doesn't work properly!

The error still exists, however...

[RLScott]

Originally Posted by Ubermatik

Ah! Thanks for spotting that! It would have been a pain to find later on, when I realised the game doesn't work properly!

The error still exists, however...

You mean the error that says "Expected expression before CGPoint" even though you now don't have CGPoint, but CGPointMake?

[Ubermatik]

Yes - as in, it's referring to the first part of that line, where it says:

CGPoint compLocation = CGPointMake(paddlegreen.center.x + kCompMoveSpeed, paddlegreen.center.y);

At least, I think that's what it is referring to.

[RLScott]

So what does the error say now, exactly?

[Ubermatik]

"Expected expression before CGPoint"

[Ubermatik]

I found these solutions - but unfortunately, non of them work...

Objective-C Tip: Switch Statements | Scyanide's World

[RLScott]

Post what the code looks like now, after you fixed the CGPoint into CGpointMake.

[Ubermatik]

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];
	self.gameState = kGameStatePaused;
	pucVelocity = CGPointMake(kPucSpeedX,KPucSpeedY);
	[NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:@selector(gameLoop) userInfo:nil repeats:YES];
}

-(void) gameLoop {
	if(gameState == kGameStateRunning) {
		
		puc.center = CGPointMake(puc.center.x + pucVelocity.x , puc.center.y + pucVelocity.y);
		
		if(puc.center.x > self.view.bounds.size.width || puc.center.x < 0) {
			pucVelocity.x = -pucVelocity.x;
		}
		
		if(puc.center.y > self.view.bounds.size.height || puc.center.y < 0) {
			pucVelocity.y = -pucVelocity.y;
		}
	} else {
		if (tapToBegin.hidden) {
			tapToBegin.hidden = NO;
		}
	}
	
		if (CGRectIntersectsRect(puc.frame,paddleblue.frame)) {
		if(puc.center.y < paddleblue.center.y) {
			pucVelocity.y = -pucVelocity.y;
			NSLog(@"%f %f",puc.center,paddlegreen.center);
			}
		}
	
		if (CGRectIntersectsRect(puc.frame,paddlegreen.frame)) {
			if(puc.center.y > paddlegreen.center.y) {
			pucVelocity.y = -pucVelocity.y;
			}
		}
		
		//Begin AI
		if (puc.center.y <= self.view.center.y) {
			if(puc.center.x < paddlegreen.center.x) {
				CGPoint compLocation = CGPointMake(paddlegreen.center.x - kCompMoveSpeed, paddlegreen.center.y);
				paddlegreen.center = compLocation;
			}
	
			if(puc.center.x > paddlegreen.center.x) {
				CGPoint compLocation = CGPointMake(paddlegreen.center.x + kCompMoveSpeed, paddlegreen.center.y);
				paddlegreen.center = compLocation;
			} //End AI
		}
	} //End of GameLoop

Again, the line the error comes up in is highlighted in red.

[Ubermatik]

*Bump

Any ideas?
I'm sorry to be a pain, but I'm really eager to learn this, and getting this solved would help enormously.

[Ubermatik]

*Bump

My last try... anybody have any ideas? Thanks again.