快速附加到2D数组 [英] Swift append to 2d array

问题描述

我正在尝试在Swift中将一个值附加到2d数组中，但在第8行上却抛出了索引超出范围"错误

I'm trying to append a value to a 2d array in Swift but it's throwing me an "index out of range" error on line 8

private var cards : [[Int]] = [[]]

init() {
    //Fill cards array by adding all cards
    for i in 0...12{
        for x in 0...3{
            cards[0].append(i+2)    //append card number... 2,3,4,5 etc
            cards[1].append(x)      //append card type... hearts, diamonds, clubs and spades
                                    //with a value which represents it (0, 1, 2 and 3)
        }
    }
}

快速代码

推荐答案

由于初始化了 cards [0] 访问 cards 的内部数组> cards 作为数组的空数组，因此 cards.count = 0 ，因此 cards [0] 不存在.

You cannot access the inner arrays of cards using cards[0], since you initialize cards as an empty array of arrays and hence cards.count = 0, so cards[0] does not exist.

private var cards = [[Int]]()

init() {
    //Fill cards array by adding all cards
    for i in 0...12{
        for x in 0...3{
            cards.append([i+2,x])
        }
    }
}

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