XCODE username password settings in NSUserDefault

For Saving Username and Password I will personally suggest to use Keychain as they are more safer than NSUserDefault in terms of security since Keychain stores data in encrypted form while NSUserDefault stores as plain text. If you still want to use NSUserDefault Here's the way

FOR SAVING

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

// saving an NSString
[prefs setObject:txtUsername.text forKey:@"userName"];
[prefs setObject:txtPassword.text forKey:@"password"];

 [prefs synchronize];

FOR RETRIEVING

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

// getting an NSString
NSString *savedUsername = [prefs stringForKey:@"userName"];
NSString *savedPassword = [prefs stringForKey:@"password"];