When you write @synthesize lastCurrentDate
- you also create variable named 'lastCurrentState
', and when you write lastCurrentDate = [NSDate date];
you directly access this variable. Properties should be accessed via dot: self.lastCurrentDate = ....;
In last xCodes you don't need to write synthesize - it do it automatically, but creates variable named with '_' prefix. It equals to: @synthesize variable = _variable;