如何创建值并将其推送到 3 维数组中

Question

我需要帮助制作一个 3 维数组，我的目标是例如：

仅用于图形说明:-)，请参见下面的行

[类别：1[子类别：1[子子类别：1,2],2[子子类别：3,4]]

在上述用户选择的场景中：

category 1
subcategories: 1
subsubcategories: 1,2
subcategories: 2
subsubcategories: 3,4

然后我可以使用这些值创建一个字符串，例如：1^1:1,2^2:3,4

希望有人能理解:)

Answer 1

使用objects 而不是arrays。当您在数组元素上使用字符串索引时，array 会变成object，之后某些数组方法可能无法正常工作。为什么不从一开始就使用object。

警告！ 如果使用命名索引，JavaScript 会将数组重新定义为标准对象。 之后，一些数组方法和属性会产生不正确的结果。

这取自https://www.w3schools.com。

这是一个如何使用它的示例：

// Object = {} instead of array = []
var myObject = {};
myObject['category'] = {1: {subcategories: {1:[1,2], 2: [3,4] }} };


// For example
var anotherObject = {};
anotherObject['category'] = {1: {}, 2: {}};
anotherObject['category'][1] = [1,2];
anotherObject['category'][2] = [3,4];

// Edit: example 3
// ---------------
// result from database JSON format
var resultFromDB = {"category": {"1": {"subcategories": {"1": {"subsubcategories": [1,2]}, "2": {"subsubcategories": [3,4] }}}} };


// example of building new object from input
var myNewObject = {};
var type;

// go through the first level 
for(var index in resultFromDB)
{
  // in case you needed this is how you would check type of input
  type = typeof resultFromDB[index];
  if((type === "object") && (type !== null)) // check if its an object
  {
    // set myNewObject[index] to new object
    myNewObject[index] = {};
    // go through second level
    for(var subIndex in resultFromDB[index])
    {
        // set myNewObject[index][subIndex] as new object
        myNewObject[index][subIndex] = {};
        // go through third level
        for(var subSubIndex in resultFromDB[index][subIndex])
        {
           // simply use an '=' to get all from that level
           myNewObject[index][subIndex][subSubIndex] = resultFromDB[index][subIndex][subSubIndex];
           
        }
    }
  }
}


console.log("This is the new object");
console.log(myNewObject);
console.log("\n");
console.log("This is the original object");
console.log(myNewObject);

// If you need to extract in multiple places you could make a function for quick access
function returnObject(incomingObject)
{
    var myNewObject = {};
    var type;
    
    // ... copy paste here all the above code from example 3 except resultFromDB
    
    return myNewObject;
}

// then just call it from anywhere
var theNewestObject = returnObject(resultFromDB);