When the following line of code executed,
[newTutorials addObject:tutorial];
What it does is , it add the address (reference) of tutorial object which you created in the previous line to the array newTutorials.
Your confusion is this : " You haven't set the values for the tutorial object inside the array but why is it displaying mytitle and myurl when you NSLog
ed the propeties of tutorials?" The answer is simple "You've not stored the tutorial object inside the array but you have stored a reference to the tutorial object"
Since when you've stored the reference and you've done the following to tutorial object :
tutorial.title = @"mytitle";
tutorial.url = @"myurl";
When you try to print the properties of the reference stored in the array, it prints mytitle and myurl because that is what you've assigned to the actual object's properties.