通用函数不会在tableView.reloadData（）之后更新tableview单元格中的label的值

Question

I have a function where I am incrementing the value of the label as below

@IBAction func buttonClicked(_ sender: UIButton) {
        let indexPath = indexPath(sender: sender, tableView: profileTableView)

        array[Int((indexPath.row))].likes = String(Int(array[Int((indexPath.row))].likes)!+1)
        self.userProfileTableView.reloadData()
    } 

In the above function after the reloadData value of the label gets incremented to the next number, But when I make it a generic function in an extension as below the value of the label does not increment

func buttonClicked(data:String,tableView:UITableView) {
        let data = String(Int(data)!+1)
        print("Incremented data", data)
        tableView.reloadData()
    }

I am calling the function as following but the label does not get updated with the incremented value . It retains the old value.

buttonClicked(data: feeds[Int((indexPath.row))].likes, tableView: userProfileTableView)

Any help will be appreciated . Thank you.

Answer 1

you should change your code to this.

let numLikes = Int(feeds[Int((indexPath.row))].likes)!
feeds[Int((indexPath.row)).likes = String(numLikes)

Because String is a value types.

When you do this.

buttonClicked(data: feeds[Int((indexPath.row))].likes, tableView: userProfileTableView)

func buttonClicked(data:String,tableView:UITableView) {
    let data = String(Int(data)!+1)
    print("Incremented data", data)
    tableView.reloadData()
}

1) New value variables data in func buttonClicked will be created and has value = feeds[Int((indexPath.row))].likes

2) when you change data , it just change data but not feeds[Int((indexPath.row))].likes

Look at Value and Reference Type for more info.

Answer 2

Actually You didn't update the array object with updated value in your generic method.

Either you may have to update the incremented value in array OR send your array to the generic function with selected index.

Example:

func buttonClicked(feeds:[Feed], index:Int, tableView:UITableView) {

        feeds[index].likes = String(Int(feeds[index].likes)!+1)
        tableView.reloadData()
    }

But I don't say this as generic function, since It's using for minimal places with minimal code and there is no generic types to reuse.

Thanks!