UILabel text updation - ios

Question

I have aUILabel which I want to update.
If I will login with a user name then the UILabel will be updated with that user name,which it is doing correctly and storing the value.
Now I want whenever i will logout then the UILabel text should return the previous value which it stored deleting the new value.
Can you please help me with this.
After login I have updated my UiLabel text like this
-(void)updateUserName:(NSNotification*)noti
{
NSDictionary* userInfo = [noti userInfo];
self.user.firstName = [userInfo valueForKey:#"FirstName"];
self.user.lastName = [userInfo valueForKey:#"LastName"];
if (self.user.firstName != nil && self.user.firstName.length > 0 && self.user.lastName.length > 0)
{
self.userName.text = [NSString stringWithFormat:#"%# %#",self.user.firstName, self.user.lastName];
}
}
then after logout I need to retrieve the old data of UiLabel.

Answer 1

NSString *userName =[NSString stringWithFormat:#"%# %#",self.user.firstName, self.user.lastName];
[[NSUserDefaults standardUserDefaults] setObject:valueToSave forKey:#"preferenceName"];
[[NSUserDefaults standardUserDefaults] synchronize];
save username to NSUserdefaults
NSString *userName = [[NSUserDefaults standardUserDefaults]
stringForKey:#"preferenceName"];
Take the username whenever you want and assign it to UILabel name
whenever the user got Logout clear the NSuserdefaults
NSString *userName =#"";
[[NSUserDefaults standardUserDefaults] setObject:valueToSave forKey:#"preferenceName"];
[[NSUserDefaults standardUserDefaults] synchronize];