Javascript在数组中重复键存储值答案

【问题标题】：Javascript duplicate key store value in arrayJavascript在数组中重复键存储值
【发布时间】：2021-11-22 17:26:34
【问题描述】：

我有一个 firebase 集合，我已成功获取如下值

One Data set
{
    
    "region": [
        "region"
    ],
   
    "gender": [
        "female"
    ],
 
}
Another Data set
{

    
    "region": [
        "region"
    ],
   
    "gender": [
        "female"
    ],
 
}

我尝试过的只是映射

module.where("gender", "array-contains", 'female')
    .get()
    .then((querySnapshot) => {
        querySnapshot.forEach((doc) => {
            
            console.log(doc.data()["region"][0].toLowerCase(), " => ", doc.data()["gender"][0]);
    
    })
    .catch((error) => {
        console.log("Error getting documents: ", error);
    });

现在我有多个表示同一个区域的值，所以我想像这样分组

region = [female,female,female,female e.t.c]

或者简单来说，如果一个区域出现多次，只需为该区域创建一个数组并为该重复区域名称附加性别值。请帮帮我。

【问题讨论】：

标签： javascript arrays firebase

【解决方案1】：

我成功了，也许它会帮助将来遇到与我类似问题的人

#步骤 1 我创建了两个变量

var collectionResults = [];
var groupedCollectionResults = {};

#步骤 2 我将 firebase 对象推送到 collectionResults

collectionResults.push(doc.data());

#步骤 3 然后我用值映射 collectionResults 重复项

 collectionResults.forEach(function(a) {
        groupedCollectionResults[a.region] = groupedCollectionResults[a.region] || [];
        groupedCollectionResults[a.region].push({ gender: a.gender });
    });

#结果

{
    "region": [
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        }
    ],
    "region2": [
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        },
        {
            "gender": [
                "female"
            ]
        }
    ],
   
}

#结论现在我可以计算特定区域的性别长度了，谢谢！！

【讨论】：