swift tableview how to select all rows

Question

I have Button in tableview I want when I press that button will select all cell rows, how to do that? I tried alot but I got nothing

I\'m so confused how to make the but

Answer 1

In cellForRowAtIndexPath:

UITableViewCell *cell...

cell.accesoryType = isSelectAll ? UITableViewCellAccessoryCheckmark : UITableViewCellAccessoryNone;