isKindOfClass returns TRUE every time?

Question 1

What you want is to use the method isMemberOfClass: instead. (Check out Apple Documentation for isMemberOfClass method)

isMemberOfClass:- Returns a Boolean value that indicates whether the receiver is an instance of a given class. (required)

Whereas (Check out Apple Documentation for isKindOfClass: method)

isKindOfClass:- Returns a Boolean value that indicates whether the receiver is an instance of given class or an instance of any class that inherits from that class. (required)

So basically when you do your isKindOfClass: check it is returning TRUE for any subclass of UIView so this includes UIButton, UILabel, etc

So change if ([[viewsToRemove objectAtIndex:i]isKindOfClass:[UIView class]]) to if ([[viewsToRemove objectAtIndex:i] isMemberOfClass:[UIView class]])

An example of the inheritance for UILabel is like UILabel>> UIView >> UIResponder >> NSObject. So when you do isKindOfClass:[UIView class] this will return TRUE for UILabel because UILabel as you can see is a subclass of UIView but if we did isMemberOfClass:[UIView class] we ignore any subclassed objects like UILabel, so this will return FALSE for UILabel but still return TRUE for UIView.

Another solution would be when creating your UIVeiws give them a tag so when it comes to removing them you can just get the specific view you want to remove using viewWithTag:.

Question 2

isKindOfClass returns true for any derived classes as well. Because all user interface related classes are derived from UIView, this method returns true for all objects in your case.

Use code like this, if you just want to test for a UIView class:

if ([obj class] == [UIView class]) {
}

This code just checks for objects of the type UIView.

Question 3

The problem with you is that every thing in your view hierarchy is having UIView as its base class, so you are getting True every time. One possible solution to deal with this is as follows:

Give some what special tag to your UIView as if normally you are giving tag as 3, then you can just multiply its tag with 1000, now on getting True, you can calculate that if a UIView is containing three 0's, then remove it else keep it :)

Question 4

Here is another way.

UIView *v;
for (int i=0; i<viewsToRemove.count; i++)
{
    v = [viewsToRemove objectAtIndex:i]
    if ([NSStringFromClass([v class]) isEqualToString:@"UIView"])
    {
        //Remove view
    }
}

Among the other answer's, I think using the isMemberOfClass mentioned by Popeye is the right way to do it.