如何将单击的最新按钮标签添加到数组中

Question

I have created 5 views using Page view controller. Each view has 4 buttons. When I click any button, the tag of that button gets added to an array. Now, the situation is..Say, I opened view 1..I clicked a button..the button's tag gets added to the array. when I click another button in the same view, this button's tag also gets added to the array. The task is to remove the previously clicked button's tag from the array and only the latest one should persist. Any help? Thank You

Answer 1

I suggest you to use a dictionary instead of array. That way you can easily replace the object related to a specific key.

[dictionary setObject:object key:somekey];

Answer 2

you better keep the tag values in NSMutableSet object which will help you in avoiding duplicates.

you directly add button object to NSMutableSet and check if the button is available in NSMutableSet remove the button from NSMutableSet else add it to the NSMutableSet

NSMutableSet *set;
    [set addObject:senderButton];
    if([set containsObject:senderButton]) {
     //set contains button remove that button
    } else {
        // set doesn't contains button add it
    }

Answer 3

Add null objects intially in NSMutableDictionary to check whether button clicked or not

//number depends on numbers of view in page view controller
for(int i=0; i<[yourPageViewController.viewControllers; i++)
    [yourMutDictionary setObject:[NSNull null] forKey:[NSString stringWithFormat:@"%d",i]];

UIButton's click event will be contain below lines of code

-(IBAction)btnClickedAction:(id)sender
{
   UIButton *btnClicked = (UIButton *)sender;
   NSUInteger index = yourPageViewController.pageControl.currentPage
   [yourMutDictionary setObject:[NSString stringWithFormat:@"%d",btnClicked.tag] forKey:[NSString stringWithFormat:@"%i",index]];
}