UiCollectionViewCell border moves cells when i scroll - ios

Question

So pretty much, when I try to scroll my UICollectionView while I a cell is selected, shown by a thin orange border, when I scroll back a different cell has the border. I read that it had something to do with cell's being reused. Anyways I found some code online, but just been having a hard time adapting it to multiple selection.
Found a solution to this problem all you have to do is make an array of selected cells and add or remove borders in
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
method
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
//each cell is refreshed when page is scrolled
//Matches every cell to see if it is selected or not and adds or removes borders accordinglly
NSNumber *rowNsNum = [NSNumber numberWithUnsignedInt:indexPath.item];
if ( [selectedCellsArray containsObject:[NSString stringWithFormat:#"%#",rowNsNum]] )
{
[cell.layer setBorderColor:[UIColor orangeColor].CGColor];
cell.layer.borderWidth = 5.0f;
}
else
{
[cell.layer setBorderColor:[UIColor clearColor].CGColor];
cell.layer.borderWidth = 0.0f;
}
return cell;
}
-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{
//Adds cells indexPath to selectedCellsArray and adds border around the cell right away
NSLog(#"selected");
UICollectionViewCell*selectedCell = [collectionView cellForItemAtIndexPath:indexPath];
if (![selectedCellsArray containsObject:[NSString stringWithFormat:#"%d",indexPath.item]] ) {
[selectedCellsArray addObject:[NSString stringWithFormat:#"%d",indexPath.item]];
[selectedCell.layer setBorderColor:[UIColor orangeColor].CGColor];
selectedCell.layer.borderWidth = 5.0f;
NSLog(#"add");
}
NSLog(#"keep track of array:%#", selectedCellsArray);
}
-(void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath{
//Removes cells indexPath from selectedCellsArray and removes border form cell right away
NSLog(#"deselected");
UICollectionViewCell*deselectedCell = [collectionView cellForItemAtIndexPath:indexPath];
if ( [selectedCellsArray containsObject:[NSString stringWithFormat:#"%d",indexPath.item]] )
{
[selectedCellsArray removeObject:[NSString stringWithFormat:#"%d",indexPath.item]];
[deselectedCell.layer setBorderColor:[UIColor clearColor].CGColor];
deselectedCell.layer.borderWidth = 0.0f;
NSLog(#"remove");
}
}