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);