Using NSLog for debugging

Question

I have the following code snippet in my Xcode:

NSString *digit [[sender titlelabel] text]; NSLog([digit]); 

I tried to build the application and am getting the following warning message for the line NSLog([digit]);

Warning: Format not a string literal and no format arguments 

Can you advise me how I can resolve this warning message? What does the message actually mean?

Answer 1

Try this piece of code:

NSString *digit = [[sender titlelabel] text]; NSLog(@"%@", digit); 

The message means that you have incorrect syntax for using the digit variable. If you're not sending it any message - you don't need any brackets.

Answer 2

Use NSLog() like this:

NSLog(@"The code runs through here!"); 

Or like this - with placeholders:

float aFloat = 5.34245; NSLog(@"This is my float: %f \n\nAnd here again: %.2f", aFloat, aFloat); 

In NSLog() you can use it like + (id)stringWithFormat:(NSString *)format, ...

float aFloat = 5.34245; NSString *aString = [NSString stringWithFormat:@"This is my float: %f \n\nAnd here again: %.2f", aFloat, aFloat]; 

You can add other placeholders, too:

float aFloat = 5.34245; int aInteger = 3; NSString *aString = @"A string"; NSLog(@"This is my float: %f \n\nAnd here is my integer: %i \n\nAnd finally my string: %@", aFloat, aInteger, aString);