CODEWITHSUNDEEP
xcodeswift4
james
james

Reputation: 81

Adding values in a tableView to a label Swift4

I am trying to take the values that I add to the tableview and add them to my totalLabel. I have attached my code and a screenshot below to help. In the example, it does not add to the totalLabel. item 1 plus item 2 should be $2 and let's say I add another item for $5 then it would be $7. 

 import UIKit
 import AVFoundation

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {


@IBOutlet weak var tableView: UITableView!
@IBOutlet weak var totalLabel: UILabel!


var items: [Item] = []

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

}

@IBAction func addItem(_ sender: Any) {

    let alert = UIAlertController(title: "Add Item", message: "Add item And Price", preferredStyle: .alert)
    alert.addTextField { (UITextField) in
        UITextField.placeholder = "Enter Item Name"
    }
    alert.addTextField { (UITextField) in
        UITextField.placeholder = "Enter Item Price"
        UITextField.keyboardType = .numbersAndPunctuation
    }
    alert.addAction(UIAlertAction(title: "Add", style: .default, handler: { (UIAlertAction) in
        let content = alert.textFields![0] as UITextField
        let content2 = alert.textFields![1] as UITextField
        let value = "\(content2.text!)"

        let item = Item(itemName: "\(content.text!)", itemPrice: Double(value)!)


        self.items.append(item)

        self.tableView.reloadData()

        guard let total = Double(self.totalLabel.text!) else { return }
        let sum = String(total + Double(value)!)
        self.totalLabel.text = sum


    }))
    alert.addAction(UIAlertAction(title: "Cancel", style: .destructive, handler: nil))

    self.present(alert, animated: true, completion: nil)

}


func numberOfSections(in tableView: UITableView) -> Int {
    return 1
}

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return items.count
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
    let items = self.items[indexPath.row]
    cell.textLabel?.text = items.itemName
    cell.detailTextLabel?.text = "$\(String(items.itemPrice))"

    var totalAmount = 0.0
    for value in self.items {
        totalAmount = totalAmount + items.itemPrice

        print(value)
        print(totalAmount)

    }

    totalLabel.text = "Total is $\(totalAmount)"
    return cell
}

func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
    return "Grocery List"
}

}

enter image description here

enter image description here

Upvotes: 1

Views: 1693

Answers (3)

vadian
vadian

Reputation: 285150

As already mentioned in my answer to your previous question you have to sum up the price values in the items array

Create a function which reloads the table view and updates the total label

func reloadAll() {
   tableView.reloadData()
   let totalAmount = String(items.map{$0.itemPrice}.reduce(0.0, +))
   totalLabel.text = "Total is $\(totalAmount)"
}

Then call this method everywhere you call tableView.reloadData() for example replace these lines in the alert action

self.tableView.reloadData()

guard let total = Double(self.totalLabel.text!) else { return }
let sum = String(total + Double(value)!)
self.totalLabel.text = sum

just with 

self.reloadAll()

And delete the following lines in cellForRow. It's pointless to update the label in this method because the same computation is performed items.count times (the loop runs items.count² times!)

var totalAmount = 0.0
for value in self.items {
    totalAmount = totalAmount + items.itemPrice

    print(value)
    print(totalAmount)

}

totalLabel.text = "Total is $\(totalAmount)"

Upvotes: 3

andesta.erfan
andesta.erfan

Reputation: 998

just replace this for loop instead of existing loop in cellForRowAt

    for value in self.items {
        totalAmount = totalAmount + value.itemPrice
    }

Upvotes: 2

Pratik Prajapati
Pratik Prajapati

Reputation: 1105

Update this method 

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
    let items = self.items[indexPath.row]
    cell.textLabel?.text = items.itemName
    cell.detailTextLabel?.text = "$\(String(items.itemPrice))"

    var totalAmount = 0.0
    for value in self.items {
      totalAmount = totalAmount + items.itemPrice
    }

    totalLabel.text = "Total is $\(totalAmount)"
    return cell
}

I hope this is what you looking.

Upvotes: 0

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