Question

我试图为游戏SET生成卡片组，或者，对于那些不知道那是什么的人，我试图用表单中的独特元素填充数组[a, b, c, d]，其中0 <= a, b, c, d <= 2（81个元素）。所以，我想要[[0, 0, 0, 0,], [0, 0, 0, 1], ... , [2, 2, 2, 2]]（顺序并不重要）。这是我到目前为止的代码：

var deck = [],
    count = [0, 0, 0, 0];
for (var i = 0; i < 81; i++) { // go through all combos
    deck.push(count); // append the current modification of count to deck
    // increment count by 1, carrying "tens" if necessary
    for (var j = 3; count[j] === 2; j--) {
        // if the "digit" is 2, make it 0 since it overflows
        count[j] = 0;
    }
    // j is the first "digit" of count that isn't already 2, so we add 1 to it
    count[j]++;
}

相反，这似乎做的是用最后修改deck填充count数组;如果i的上限是81，那么它是[0, 0, 0, 0]，因为它一直翻转，如果你将边界更改为任何更低，它将相应地作出响应。为什么会这样？我犯了什么错误？

Answer 1

请记住，您每次迭代都会将同一count推送到deck，这意味着任何计数更改都会反映到count中的所有其他deck因为他们都引用了相同的array

您可以使用.slice克隆具有前一个count中相同值的新数组。

＆＃13;

var deck = [],
    count = [0, 0, 0, 0];
for (var i = 0; i < 81; i++) { // go through all combos

    // Clone a new array from previous one.
    count = count.slice();


    deck.push(count); // append the current modification of count to deck
    // increment count by 1, carrying "tens" if necessary
    for (var j = 3; count[j] === 2; j--) {
        // if the "digit" is 2, make it 0 since it overflows
        count[j] = 0;
    }
    // j is the first "digit" of count that isn't already 2, so we add 1 to it
    count[j]++;
}
console.log(deck);

＆＃13;

循环以在每次迭代时修改变量，并附加每个新的＆＃34;修改＆＃34;到一个数组

1 个答案: