Question

有两个数组，例如：

class TeamDetailsController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        setupViews()
        print(textView.text)
    }

    lazy var scrollView: UIScrollView = {
        let sv = UIScrollView(frame: self.view.bounds)
        sv.backgroundColor = .white
        sv.translatesAutoresizingMaskIntoConstraints = false
        sv.layer.borderWidth = 5
        return sv
    }()

    let profileImageView: UIImageView = {
        let imageView = UIImageView()
        imageView.image = UIImage(named: "team-tony")
        imageView.contentMode = .scaleAspectFill
        imageView.layer.cornerRadius = 50
        imageView.layer.masksToBounds = true
        imageView.clipsToBounds = true
        imageView.translatesAutoresizingMaskIntoConstraints = false
        return imageView
    }()

    let nameLabel: UILabel = {
        let label = UILabel()
        label.text = "Jared 'Donald' Dunn"
        label.font = UIFont.systemFont(ofSize: 20, weight: .bold)
        label.translatesAutoresizingMaskIntoConstraints = false
        return label
    }()

    let textView: UITextView = {
        var tv = UITextView()
        tv.translatesAutoresizingMaskIntoConstraints = false
        tv.textColor = .black
        tv.font = UIFont.systemFont(ofSize: 16)
        tv.isEditable = false
        return tv
    }()

    func setupViews() {

        view.backgroundColor = .white
        view.addSubview(scrollView)

        scrollView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 0).isActive = true
        scrollView.leftAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leftAnchor, constant: 0).isActive = true
        scrollView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: 0).isActive = true
        scrollView.rightAnchor.constraint(equalTo: view.safeAreaLayoutGuide.rightAnchor, constant: 0).isActive = true

        scrollView.addSubview(profileImageView)
        profileImageView.centerXAnchor.constraint(equalTo: scrollView.centerXAnchor).isActive = true
        profileImageView.topAnchor.constraint(equalTo: scrollView.topAnchor, constant: 20).isActive = true

        scrollView.addSubview(nameLabel)
        nameLabel.centerXAnchor.constraint(equalTo: scrollView.centerXAnchor).isActive = true
        nameLabel.topAnchor.constraint(equalTo: profileImageView.bottomAnchor, constant: 10).isActive = true

        scrollView.addSubview(textView)
        textView.topAnchor.constraint(equalTo: nameLabel.bottomAnchor).isActive = true
        textView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor).isActive = true
        textView.leftAnchor.constraint(equalTo: scrollView.leftAnchor, constant: 20).isActive = true
        textView.rightAnchor.constraint(equalTo: scrollView.rightAnchor, constant: 20).isActive = true


    }

}

在此操作之后，我想将第二个元素添加到第一个元素中，arr1 = ["a", "b"]; arr2 = ["c", "d"];应该看起来像arr1。没关系，["a", "b", "c", "d"]会发生什么。

我尝试了经典方法：arr2，结果看起来像：arr1.push(arr2)。

Answer 1

使用Array.prototype.concat()

var arr1 = ["a", "b"];
var arr2 = ["c", "d"];
arr1 = arr1.concat(arr2);
console.log(arr1)

Answer 2

您可以使用ES6语法来做到这一点：

您可以进行以下操作：

const arr1 = ["a", "b"];
const arr2 = ["c", "d"];

arr1 = [...arr1,...arr2]

console.log(arr1)

有关点差运算符的定义：

允许将迭代器（例如数组表达式或字符串）扩展到期望零个或多个参数（用于函数调用）或元素（用于数组文字）的位置，或者将对象表达式扩展到零或期望有更多的键值对（用于对象文字）。 （定义来自MDN）

在ES5语法中，您应该使用.concat()函数，但现在在ES6中更容易

Answer 3

使用传播语法：

var arr1 = ["a", "b"];
var arr2 = ["c", "d"];
arr1 = [...arr1,...arr2];
console.log(arr1);

使用 Array.concat（）：

var arr1 = ["a", "b"];
var arr2 = ["c", "d"];
arr1 = arr1.concat(arr2);
console.log(arr1);

将一个数组的元素添加到另一个数组

3 个答案: