Question

我在Javascript中遇到嵌套for循环的奇怪问题。我想用一种语言填充一系列答案，然后将这些答案包含在另一个数组中。问题是，当我看到输出时，只使用内部for循环的数组的最后一次迭代。我认为它与基于其他答案的闭包有关，但由于我不具备多种功能，所以我不确定这是怎么回事。这是JS Fiddle。

以下是代码：

var answer_array = [];
var content_array = [];
var i18n_array = ['en', 'fr', 'es'];

for (var i18nCount = 0; i18nCount < 3; i18nCount++) {

    var i18nLang = i18n_array[i18nCount];

        for (var ansIndex = 0; ansIndex < 3; ansIndex++) {
            answer_array[ansIndex] = {
                value: 'This is answer # ' + ansIndex + ' in this language ' + i18nLang
            };
        }

        console.log(i18nCount);
        console.log(i18nLang);
        console.log(JSON.stringify(answer_array,null,4));

    content_array[i18nCount] = {
        i18n: i18nLang,
        text: 'This question is in ' + i18nLang + ' language?',
        answers: answer_array,
    };
}

console.log(JSON.stringify(content_array,null,4));

它产生了这个：

    0
en
[
    {
        "value": "This is answer # 0 in this language en"
    },
    {
        "value": "This is answer # 1 in this language en"
    },
    {
        "value": "This is answer # 2 in this language en"
    }
]
1
fr
[
    {
        "value": "This is answer # 0 in this language fr"
    },
    {
        "value": "This is answer # 1 in this language fr"
    },
    {
        "value": "This is answer # 2 in this language fr"
    }
]
2
es
[
    {
        "value": "This is answer # 0 in this language es"
    },
    {
        "value": "This is answer # 1 in this language es"
    },
    {
        "value": "This is answer # 2 in this language es"
    }
]
[
    {
        "i18n": "en",
        "text": "This question is in en language?",
        "answers": [
            {
                "value": "This is answer # 0 in this language es"
            },
            {
                "value": "This is answer # 1 in this language es"
            },
            {
                "value": "This is answer # 2 in this language es"
            }
        ]
    },
    {
        "i18n": "fr",
        "text": "This question is in fr language?",
        "answers": [
            {
                "value": "This is answer # 0 in this language es"
            },
            {
                "value": "This is answer # 1 in this language es"
            },
            {
                "value": "This is answer # 2 in this language es"
            }
        ]
    },
    {
        "i18n": "es",
        "text": "This question is in es language?",
        "answers": [
            {
                "value": "This is answer # 0 in this language es"
            },
            {
                "value": "This is answer # 1 in this language es"
            },
            {
                "value": "This is answer # 2 in this language es"
            }
        ]
    }
]

Answer 1

你一遍又一遍地重复使用相同的answer_array，覆盖它的3个成员。

在每次外部循环迭代时创建一个新数组，而不是在循环之外。

例如：

var content_array = [];
var i18n_array = ['en', 'fr', 'es'];

for (var i18nCount = 0; i18nCount < 3; i18nCount++) {
    var answer_array = []; // Move this inside
    var i18nLang = i18n_array[i18nCount];

在Javascript中使用简单的嵌套for循环问题

1 个答案: