Please Help NSString Problem

wilky94 · 12-30-2009, 06:44 PM

Hello,
i am currently making a quiz app and i have a score label which i need to either add 1 for a correct answer or delete one for a incorrect answer. so i have this code

Code:

	result.text = @"Correct";
	
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] + 1)];

This works fine however when i add an if statement for the next question it dosent work. This is the if statement

Code:

if (question.text == @"What was the first programmable computer called?") {
		
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];	
	
	result.text = @"Incorrect";

QuantumDoja · 12-30-2009, 07:05 PM

Hi, First of all, I would keep the score counting seperate from the actual text, it will make it alot easier, 2nd, use NSString's isEqualTo method to compare strings.

rocotilos · 12-30-2009, 07:46 PM

Quote:

Originally Posted by wilky94

Hello,
i am currently making a quiz app and i have a score label which i need to either add 1 for a correct answer or delete one for a incorrect answer. so i have this code

Code:

	result.text = @"Correct";
	
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] + 1)];

This works fine however when i add an if statement for the next question it dosent work. This is the if statement

Code:

if (question.text == @"What was the first programmable computer called?") {
		
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];	
	
	result.text = @"Incorrect";

You can try this:

Code:

if (question.text isEqualToString:@"What was the first programmable computer called?") {
		
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];	
	
	result.text = @"Incorrect";
}

wilky94 · 12-31-2009, 07:24 AM

Quote:

Originally Posted by rocotilos

You can try this:

Code:

if (question.text isEqualToString:@"What was the first programmable computer called?") {
		
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];	
	
	result.text = @"Incorrect";
}

Thanks, when i try this i get an error saying "Expected ')' before 'isEqualToString' do you know why this is.

Nikh · 12-31-2009, 09:53 AM

You should add [], i.e. write
[question.text isEqualToString:@"What was the first programmable computer called?"]

rocotilos · 12-31-2009, 10:56 AM

Sorry I didnt get back to u earlier.
Nikh got it right. u need to add the [] on it.
It is an evaluating method. So it will return false or true.

Ie,

Code:

if ([question.text isEqualToString:@"What was the first programmable computer called?"])

OR in its more understandable form:

Code:

if ([question.text isEqualToString:@"What was the first programmable computer called?"]==YES)

wilky94 · 12-31-2009, 11:01 AM

Quote:

Originally Posted by rocotilos

Sorry I didnt get back to u earlier.
Nikh got it right. u need to add the [] on it.
It is an evaluating method. So it will return false or true.

Ie,

Code:

if ([question.text isEqualToString:@"What was the first programmable computer called?"])

OR in its more understandable form:

Code:

if ([question.text isEqualToString:@"What was the first programmable computer called?"]==YES)

Its still not working, when i run it the score stays the same do you know what else i can try

Ins3rtNam3H3r3 · 12-31-2009, 01:21 PM

Quote:

Originally Posted by wilky94

Its still not working, when i run it the score stays the same do you know what else i can try

Add an NSLog in the if statement to see if it evaluates to true. If it doesn't, NSLog the value of question.text right before the if to see what it is.

wilky94 · 12-31-2009, 04:40 PM

Quote:

Originally Posted by Ins3rtNam3H3r3

Add an NSLog in the if statement to see if it evaluates to true. If it doesn't, NSLog the value of question.text right before the if to see what it is.

i dont understand what you mean could you send me the code i am new to iphone development

Ins3rtNam3H3r3 · 12-31-2009, 08:50 PM

Quote:

Originally Posted by wilky94

i dont understand what you mean could you send me the code i am a nube to iphone development

I mean you should do:

Code:

if (question.text isEqualToString:@"What was the first programmable computer called?") {
		
        NSLog(@"IF statement true"); 

	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];	
	
	result.text = @"Incorrect";
}

to check if the IF is true, and if its not you should do:

Code:

NSLog(question.text);

if (question.text isEqualToString:@"What was the first programmable computer called?") {

	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];	
	
	result.text = @"Incorrect";
}

to see what question.text is and why it's not evaluating to true.

rocotilos · 01-01-2010, 02:06 PM

Quote:

Originally Posted by wilky94

Its still not working, when i run it the score stays the same do you know what else i can try

May I know how are you setting the question.text? If there are a space after the ? at the end, this code wont work too. I cant really help u without more details to the codes.

wilky94 · 01-02-2010, 08:07 AM

Quote:

Originally Posted by rocotilos

May I know how are you setting the question.text? If there are a space after the ? at the end, this code wont work too. I cant really help u without more details to the codes.

I have checked that all the questions are the same. this is all the code i have.

Code:

- (IBAction)A:(UIButton *)sender {
    
	result.text = @"Correct";
	
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] + 1)];
	
	NSLog(question.text);
	
	if ([question.text isEqualToString:@"What was the first programmable computer called?"]) {
		
		score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];	
		
		result.text = @"Incorrect";
	}		
	
	

	
		
			
	
}

- (IBAction)B:(UIButton *)sender {
	
	
	result.text = @"Incorrect";
	
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];
	
	
	if ([question.text isEqualToString:@"What was the first programmable computer called?"]) {
		
		score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] + 1)];
		
		result.text = @"Correct";
		
	
		
	}	
}

- (IBAction)C:(UIButton *)sender {
	
	result.text = @"Incorrect";
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];
	
	if ([question.text isEqualToString: @"What was the first programmable computer called?"]) {
			
	result.text = @"Incorrect";
		
	
		score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];
		
	}	
    
}

- (IBAction)D:(UIButton *)sender {
	
	result.text = @"Incorrect";
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];
	
	if ([question.text isEqualToString: @"What was the first programmable computer called?"]) {
		
		
		score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];
		
		
		result.text = @"Incorrect";
		
		
		
	}	
    
}

- (IBAction)back:(UIButton *)sender {
	
	[self dismissModalViewControllerAnimated:YES];
	}



- (IBAction)next:(UIButton *)sender {
	question.text = @"What was the first programmable computer called?";
	
	answerA.text = @"ZX";
	answerB.text = @"Z1";
	answerC.text = @"ZZ";
	answerD.text = @"Z0";
	number.text = @"2";

rocotilos · 01-02-2010, 08:26 AM

Quote:

Originally Posted by wilky94

I have checked that all the questions are the same. this is all the code i have.

Code:

- (IBAction)A:(UIButton *)sender {
    
	result.text = @"Correct";
	
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] + 1)];
	
	NSLog(question.text);
	
	if ([question.text isEqualToString:@"What was the first programmable computer called?"]) {
		
		score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];	
		
		result.text = @"Incorrect";
	}		
	
	

	
		
			
	
}

- (IBAction)B:(UIButton *)sender {
	
	
	result.text = @"Incorrect";
	
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];
	
	
	if ([question.text isEqualToString:@"What was the first programmable computer called?"]) {
		
		score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] + 1)];
		
		result.text = @"Correct";
		
	
		
	}	
}

- (IBAction)C:(UIButton *)sender {
	
	result.text = @"Incorrect";
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];
	
	if ([question.text isEqualToString: @"What was the first programmable computer called?"]) {
			
	result.text = @"Incorrect";
		
	
		score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];
		
	}	
    
}

- (IBAction)D:(UIButton *)sender {
	
	result.text = @"Incorrect";
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];
	
	if ([question.text isEqualToString: @"What was the first programmable computer called?"]) {
		
		
		score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];
		
		
		result.text = @"Incorrect";
		
		
		
	}	
    
}

- (IBAction)back:(UIButton *)sender {
	
	[self dismissModalViewControllerAnimated:YES];
	}



- (IBAction)next:(UIButton *)sender {
	question.text = @"What was the first programmable computer called?";
	
	answerA.text = @"ZX";
	answerB.text = @"Z1";
	answerC.text = @"ZZ";
	answerD.text = @"Z0";
	number.text = @"2";

Hi.. I think I may have guessed at what is wrong (or not wrong rather).

I see you are adding the score before the if statement (see the Red fonts i highlighted above). I think the question is detected, but since u are +1 to the score before the if statement, so after the IF STATEMENT is TRUE, it would -1 to score again which sums up to, 0. So no changes in the score was made.

I may be wrong though.. Is that line correct? Seems a bit weird for me.

wilky94 · 01-02-2010, 12:05 PM

Quote:

Originally Posted by rocotilos

Hi.. I think I may have guessed at what is wrong (or not wrong rather).

I see you are adding the score before the if statement (see the Red fonts i highlighted above). I think the question is detected, but since u are +1 to the score before the if statement, so after the IF STATEMENT is TRUE, it would -1 to score again which sums up to, 0. So no changes in the score was made.

I may be wrong though.. Is that line correct? Seems a bit weird for me.

i dont get errors but i think you are correct do you know what i could do to fix this

Ins3rtNam3H3r3 · 01-02-2010, 03:56 PM

Edit - Realized i was completely wrong

rocotilos · 01-03-2010, 11:25 AM

Quote:

Originally Posted by wilky94

i dont get errors but i think you are correct do you know what i could do to fix this

Hi. Maybe u can do it like this:

Code:

- (IBAction)A:(UIButton *)sender {
    
	
	if ([question.text isEqualToString:@"What was the first programmable computer called?"]) {
		
		score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];	
		
		result.text = @"Incorrect";

                return;  
	}		
	
	result.text = @"Correct";
	
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] + 1)];
	
	NSLog(question.text);
	
}

So if the result is wrong, it would deduct 1 point from score and exit the method (using return). Then all the green code is ignored. If it is right, the if statement is ignored, and the green code is executed. I probably use a complete if..else statement.. but im not sure how ur game work. Give the above code a try.

wilky94 · 01-04-2010, 06:16 PM

Quote:

Originally Posted by rocotilos

Hi. Maybe u can do it like this:

Code:

- (IBAction)A:(UIButton *)sender {
    
	
	if ([question.text isEqualToString:@"What was the first programmable computer called?"]) {
		
		score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] - 1)];	
		
		result.text = @"Incorrect";

                return;  
	}		
	
	result.text = @"Correct";
	
	score.text = [NSString stringWithFormat:@"%i", ([score.text intValue] + 1)];
	
	NSLog(question.text);
	
}

So if the result is wrong, it would deduct 1 point from score and exit the method (using return). Then all the green code is ignored. If it is right, the if statement is ignored, and the green code is executed. I probably use a complete if..else statement.. but im not sure how ur game work. Give the above code a try.

now it is not adding 2 but still adding 1 instead of taking away 1.

rocotilos · 01-05-2010, 04:25 AM

Quote:

Originally Posted by wilky94

now it is not adding 2 but still adding 1 instead of taking away 1.

If it is correct, then u want to add 1 right? and if it is incorrect, subtract 1?

Did u input the "return;"?

wilky94 · 01-06-2010, 01:28 PM

Quote:

Originally Posted by rocotilos

If it is correct, then u want to add 1 right? and if it is incorrect, subtract 1?

Did u input the "return;"?

i must be doing the if statement wrong because now the result.text sais correct but in the if statement it is supposed to say incorrect.

wilky94 · 04-26-2010, 02:05 PM

Quote:

Originally Posted by wilky94

i must be doing the if statement wrong because now the result.text sais correct but in the if statement it is supposed to say incorrect.

Thanks to everyone. I got it working, what was wrong was I hadn't added one or subtracted 1 on the first question and therefore the others were not working.

thanks again

Rosemarry · 06-19-2010, 08:34 AM

I am reading data from a TCP/IP stream and am successfully receiving a byte array from the pre-existing server. I am now trying to find a way to convert that array to an NSString.

RLScott · 06-19-2010, 09:02 AM

Quote:

Originally Posted by wilky94

Thanks to everyone. I got it working,..

But you still have not taken the very important advice of QuantumDoja in the very first response to your posting. You definitely should not use score.text as the primary storage of the value of the score. You will have trouble later on if you don't fix it now. You should store the score in an int value as part of some object other than the view. Perhaps the view controller, or even maybe the app delegate, if the score is essentially a global singleton.

For example, suppose you push another view controller onto the navigation stack and the system decided to unload the score view. That will destroy your one and only memory of the actual score. So when the view needs to be re-created the next time it loads, you won't have any value to put in for the score.

Or, suppose someone is playing your game and they get a phone call, which forces your app to exit. After the call, they return to your app, only to find that their score has disappeared. It is much easier to save the state of an int than to save the state of the text of a view.

Robert Scott
Ypsilanti, Michigan