Question

I’m working on a little quiz app, and I was working on an algorithm to quickly proceed to the next question. The first part of the code was adequate. It worked well, but the last line threw an error. I was wondering if you could use an NSString to access a UIView variable. Here’s the code:

NSString *QuestionString = [NSString stringWithFormat:@"%d", Question]; // THE "Question" VARIABLE IS AN INT...
NSString *PlayViewString = [NSString stringWithFormat:@"%@", @"PlayView"];
NSString *ThePlayViewString = [PlayViewString stringByAppendingString: QuestionString];
NSLog(@"%@", ThePlayViewString); //WORKS GREAT TO HERE (Logged to make sure everything went well)

self.view = ThePlayViewString; // THROWS ERROR "Incompatible pointer types assigning from 'UIView *' to 'NSString *'"

UPDATE

The algorithm is inside a IBAction for a UIButton. It’s meant so that whenever you press the button, or in further questions any other object, you’ll proceed onto the next question. Thank you all for establishing that I CAN NOT use a NSString to get to a UIView.

Thanks for your help!

Answer 1

its quite clear what happens..

1. NSLog(ThePlayViewString, @"%@"); iplain wrong way round, it should be
   NSLog(@"%@",ThePlayViewString, );

2. self.view = ThePlayViewString; gives you the error "Incompatible pointer types assigning from 'UIView *' to 'NSString *'"

from this error it should be absolutely clear what is wrong. self.view is of type UIView * and if you want to assign something to it, it has to be of type UIView * as well. you cannot assign a string to a view.

Solution:

if you do not know how to create a view, this is where to look: create a view programmatically

you could create your views with .xib files (interface builder), name them after your questions and open them with the string, like that:

self.view = [[UIView alloc]initWithNibName:ThePlayViewString bundle:[NSBundle mainBundle]];

Edit for your purpose:

i would use another approach to what you are trying to do.

1. put all questions in an NSArray like that

   NSArray * array = [[NSArray alloc]initWithObjects: @”question 0″, @”question 1″, …, nil];

2. get your question number as before

3. get the next question

   NSString *nextQuestion = [[array objectAtIndex: questionNumber]]; (questionNumber must be type int)

and display it in a label:

UILabel *mylabel = [[UILabel alloc]init];
[mylabel setText:nextQuestion];

i would use interfacebuilder to make a label with a connection.
sebastian