在不替换子对象的情况下添加到Javascript对象

James 发表于 Dev

詹姆士

我试图运行一个for循环来创建新的javascript对象并将其添加到现有的javascript对象而不进行替换。

例如，我试图将其创建为输出，而不会每次都覆盖group [i]（仅添加number [i] data）：

{
    "group1": {
        "number1": "data",
        "number2": "data",
        "number3": "data"
    },
    "group2": {
        "number1": "data",
        "number2": "data"
    }
}

我的循环如下所示：

var array = [{
    "groupName": "group1",
    "number": "number1",
    "data": "data"
}, {
    "groupName": "group1",
    "number": "number2",
    "data": "data"
}, {
    "groupName": "group1",
    "number": "number3",
    "data": "data"
}, {
    "groupName": "group2",
    "number": "number1",
    "data": "data"
}, {
    "groupName": "group2",
    "number": "number2",
    "data": "data"
}]

var groupLinks = {};

for(i = 0; i < array.length; i++) {

    groupLinks[array[i].groupName] = { 
        [array[i].number]: array[i].data

}

如您在此代码中看到的那样，我的循环每次只会替换“ group1”和“ group2”。

转到0

这就是我要如何处理这个问题：

var array = [{
    "groupName": "group1",
    "number": "number1",
    "data": "data"
}, {
    "groupName": "group1",
    "number": "number2",
    "data": "data"
}, {
    "groupName": "group1",
    "number": "number3",
    "data": "data"
}, {
    "groupName": "group2",
    "number": "number1",
    "data": "data"
}, {
    "groupName": "group2",
    "number": "number2",
    "data": "data"
}];

var groupLinks = {};

array.forEach(
    function (element)
    {
        var groupName = element.groupName;
        (groupLinks[groupName] = groupLinks[groupName] || {})
            [element.number] = element.data;

    }
);

console.log(groupLinks);

在这里，当||操作员不存在时，我使用运算符创建了一个新组groupLinks[groupName]，并在每次迭代时覆盖了现有的组，并且使用了一种forEach构造来遍历数组元素。

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