ios - 连续追加到数组末尾

Question

每次按下按钮时，我都会尝试将新数字附加到数组末尾。我尝试了很多不同的方法，但还是不太明白。

我尝试过追加、插入、创建空数组等等。

import UIKit
import Foundation

var num1 = 0

class ViewController: UIViewController {

 @IBAction func button(_ sender: UIButton) {

    var digitCounts = Array(repeating: 0, count: 10)
    var number_list = [1,2,3]

    if num1 >= 0 {

    digitCounts.insert(3, at: num1)
    print(digitCounts)
    number_list.append(num1)
    num1 += 1
    print(num1)
    print(number_list)
    } 
}

结果看起来像

starting array [1,2,3] after button pressed first time [1,2,3,4] after button pressed second time [1,2,3,4,5] after button pressed third time [1,2,3,4,5,6]

Answer 1

好的，现在您已经显示了完整的代码，我可以看到问题了。每次单击按钮时都会创建新数组，但会在此函数之外存储 num1。

试试这个:

import UIKit
import Foundation


class ViewController: UIViewController {

 var num1 = 0
 var digitCounts = Array(repeating: 0, count: 10)
 var number_list = [1,2,3]

 @IBAction func button(_ sender: UIButton) {
    if num1 >= 0 {
        digitCounts.insert(3, at: num1)
        print(digitCounts)

        number_list.append(num1)
        num1 += 1
        print(num1)
        print(number_list)
    } 
}

通过将数组存储为类的属性，而不是存储在函数内部，它们将通过多次点击而保留