Text is replacing while scrolling tableview - ios

Question

I need to increment decrement label value of a particular row. I am using following method, it is working but when I scroll the table view then values are replacing with other's row.
Like I am showing two row on a screen according to design so while scrolling, first row's label value is replacing with forth row label and so on.
#IBAction func plusBtnAction(_ sender: UIButton) {
var cell:TableViewCell = self.tebleView.dequeueReusableCell(withIdentifier: "Cell")! as UITableViewCell as! TableViewCell
let indexPath = IndexPath(row: sender.tag, section: 0)
cell = (self.tebleView.cellForRow(at: indexPath) as? TableViewCell)!
if cell.tag == sender.tag {
print(sender.tag)
print(cell.countLbl.tag)
cell.countLbl.text = "\(Int(cell.countLbl.text!)! + 1)"
}
}

Answer 1

Remember, you are reusing the cells - dequeueReusableCell each time you need to display a new cell, so what's happening here is the first row disappears and when it is redisplayed, you are using the cell that was used for row 4.
The solution to this is to keep a track of your counter in an array outside of the tableView (table, not teble :-) ) Something like this...
var tableDataCounters : [Int] = []
// set up your data ...
cell.countLbl.text = "\(tableDataCounters[indexPath.row] + 1)"

Answer 2

By using dequeueReusableCell(withIdentifier: ) method of UITableView, you are initially creating cells and later on reusing those created cells. You are facing this problem due to this. Since you have only one row whose text you need to change, it's better to keep the text for that row stored externally. For the plusBtnAction, it's better to do the following:
var cellLabelTextArray: [String] = [] // populate this with data for each cell
#IBAction func plusBtnAction(_ sender: UIButton) {
var cell:TableViewCell = self.tebleView.dequeueReusableCell(withIdentifier: "Cell")! as UITableViewCell as! TableViewCell
let indexPath = IndexPath(row: sender.tag, section: 0)
var cellLabelText = cellLabelTextArray[indexPath.row]
cellLabelText = "\(Int(cellLabelText) + 1)"
cellLabelTextArray[indexPath.row] = cellLabelText
if let visiblePaths: [IndexPath] = self.tableView.indexPathsForVisibleRows {
if visiblePaths.contains(indexPath) {
self.tableView.reloadRows(at: [indexPath], with: UITableViewRowAnimation.automatic)
}
}
}
In the above code, we are checking if the indexPath is visible. If it is, then reload that particular indexPath. Otherwise, we don't need to.