increase cell count without increasing data in table of iOS - ios

Question

my data set is like
var data = [["1"],["2","3"],["4"]]
and I want to show it in table view
which I am able to using
cell.textlabel?.text = data[indexPath.section][indexPath.row]
I have a button in navigation bar which when I click should increment all the sections row by 1 without changing anything in data
and all the newly created cell textfield should say "add here"
my cell for rowat
let cell = table.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textlabel?.text = data[indexPath.section][indexPath.row]
return cell
how should I change my cell for row at so that I don't get fatal error index out of range

Answer 1

Adding to #iOSArchitect.com 's answer,
You should check the index in cellForRowAt.
The reason you are getting index out of range exception is because your numberOfCell count increases but the cell's data source remains the same.
So,
let cell = table.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
if indexPath.row < data[indexPath.section].count{
cell.textlabel?.text = data[indexPath.section][indexPath.row]
}else{
cell.textlabel?.text = "add here"
}
return cell
This may not be the precise code but I hope you get the logical answer out of this.

Answer 2

Declare a variable named extraRows and assign its initial value as 0 and add a property observer to it so that whenever it changes, it reloads the tableView
var extraRow : Int = 0 {
didSet {
self.tableView.reloadData()
}
}
After the click of the add button, update extraRow to + 1
#IBAction func addBtnClicked(_ sender : Any) {
extraRow = extraRow + 1
}
Also, update your number of rows
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return data.count + extraRows
}
Along with this, you also need to update your tableview cellForRowAtIndexPath and place a check for if indexPath.row > data.count , then show your empty celll