i\'m trying to understand how to save a simple value, an integer, in a plist. but i\'m finding on the net only solution for save dictionary and array and i don\'t understand
You can't have anything other than an array or dictionary as the root object in a plist. This is because plist files are essentially special xml files so when you are trying to read the file you ask for object at key or object at index, otherwise you have no means of obtaining your data. Also, when inserting numbers into a plist, you must wrap them in the NSNumber class. To save your objects, check out this answer.