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键不是数字时的Foreach

firebase angular javascript

Fabian Mayer · 技术社区 · 2 年前

在我的项目中,我将数组推入firebase实时数据库的表中。Firebase为每个数组生成令牌而不是数字id:

{
    "-N2mToYDj-i8ToErmaUj": {
        "anzahl": 2,
        "groesse": 0.5,
        "name": "getraenk1",
        "preis": 5.5
    },
    "-N2mX3RPnDXxWMHMJScy": {
        "anzahl": 1,
        "groesse": "0.25",
        "name": "getraenk2",
        "preis": 2.2
    },
    "-N2mXBT8c7EKlIgyrU72": {
        "anzahl": 1,
        "groesse": "0.5",
        "name": "getraenk3",
        "preis": 3.4
    },
    "-N2mXZD1BoCslj81Lcya": {
        "anzahl": 1,
        "groesse": "1",
        "name": "getraenk4",
        "preis": 5.2
    "-N2m_g8GutpAFqsN4WsP": {
        "anzahl": 1,
        "groesse": "0.33",
        "name": "getraenk5",
        "preis": 3.2
    },
}

3 回复 | 直到 2 年前

Samathingamajig 2 年前

Object.values . 如果您也关心键,请将结果包装在 Object.entries

const data = {"-N2mToYDj-i8ToErmaUj":{"anzahl":2,"groesse":0.5,"name":"getraenk1","preis":5.5},"-N2mX3RPnDXxWMHMJScy":{"anzahl":1,"groesse":"0.25","name":"getraenk2","preis":2.2},"-N2mXBT8c7EKlIgyrU72":{"anzahl":1,"groesse":"0.5","name":"getraenk3","preis":3.4},"-N2mXZD1BoCslj81Lcya":{"anzahl":1,"groesse":"1","name":"getraenk4","preis":5.2},"-N2m_g8GutpAFqsN4WsP":{"anzahl":1,"groesse":"0.33","name":"getraenk5","preis":3.2}};

Object.values(data).forEach(value => console.log("value", value));

console.log("===================");
Object.entries(data).forEach(([key, value]) => console.log("key", key, "value", value));

Daniel Black 2 年前

看起来你得到的是一个对象而不是一个列表,这就是为什么forEach不工作的原因。您需要遍历返回对象的键,并以这种方式提取相应的记录。

您可以这样做来循环键:

var object = {"one":"data-1","two":"data-2"}
var keys = Object.keys(object)
keys.forEach(function(key){
    console.log(key); 
    console.log(object[key])
})

Hossein hossein 2 年前

假设您的数据存储在 test 对象您可以使用 Object 函数以处理任何对象。要访问所有密钥,您可以尝试以下操作:

Object.keys(test).map(key => { // key in here can be for example -N2mToYDj-i8ToErmaUj
    const data = test[key] // this is the full object that each key points to
/* 
   {
        "anzahl": 2,
        "groesse": 0.5,
        "name": "getraenk1",
        "preis": 5.5
    }
*/
})