如何基于ParentID字段转换对象数组的格式？

需求说明 #

• ParentID为0的对象作为父对象，必须添加字符串类型的children字段
• ParentID不为0的对象，作为pID与其ParentID匹配的父对象的子元素，存入父对象的children字段
• 父对象无子女时，children字段为空字符串

示例输入数据 #

var JsonVal = {
    "data": {
        "Factorid": 197325,
        "orders": [
            {
                "pID": 794522,
                "Count": 1,
                "ParentID": 794551,
                "Description": "",
                "productid": "1428539",
                "UnitPrice": "300000"
            },
            {
                "pID": 794525,
                "Count": 1,
                "ParentID": 794551,
                "Description": "",
                "productid": "1428543",
                "UnitPrice": "600000"
            },
            {
                "pID": 794550,
                "Count": 2,
                "ParentID": 0,
                "Description": "",
                "productid": "1428648",
                "UnitPrice": "60000"
            },
            {
                "pID": 794551,
                "Count": 1,
                "ParentID": 0,
                "Description": "",
                "productid": "1428647",
                "UnitPrice": "250000"
            },
            {
                "pID": 794526,
                "Count": 3,
                "ParentID": 794550,
                "Description": "",
                "productid": "1428548",
                "UnitPrice": "600000"
            },
            {
                "pID": 794527,
                "Count": 1,
                "ParentID": 0,
                "Description": "",
                "productid": "1428542",
                "UnitPrice": "400000"
            }
        ]
    }
};

期望输出格式 #

{
    "data": {
        "Factorid": 197325,
        "orders": [
            {
                "pID": 794550,
                "Count": 2,
                "ParentID": 0,
                "Description": "",
                "productid": "1428648",
                "UnitPrice": "60000",
                "children": "[{                    'pID': 794526,                    'Count':3,                    'ParentID': 794550,                    'Description': '',                    'productid': '1428548',                    'UnitPrice': '600000'                 }]"
            },
            {
                "pID": 794551,
                "Count": 1,
                "ParentID": 0,
                "Description": "",
                "productid": "1428647",
                "UnitPrice": "250000",
                "children": "[                    {                       'pID': 794522,                        'Count': 1,                        'ParentID': 794551,                        'Description': '',                        'productid': '1428539',                        'UnitPrice': '300000'                    },                    {                       'pID': 794525,                        'Count': 1,                        'ParentID': 794551,                        'Description': '',                        'productid': '1428543',                        'UnitPrice': '600000'                    }                ]"
            },
            {
                "pID": 794527,
                "Count": 1,
                "ParentID": 0,
                "Description": "",
                "productid": "1428542",
                "UnitPrice": "400000",
                "children": ""
            }
        ]
    }
}

你的现有代码 #

JsonVal.orders.forEach(orders => {
  if(orders.ParentID == 0){
       orders.children="";
   }else{
     if(orders.ParentID == new_rows){
        JsonVal.orders = JsonVal.orders.filter(item => item.ParentID == orders.ParentID);
     }
   }
 });

解决方案代码 #

下面是实现需求的完整代码，步骤清晰可复用：

// 1. 创建父对象映射表，用pID作为键，快速查找父对象
const parentMap = {};
// 2. 筛选所有父对象，初始化children为空字符串并存入映射表
const parentOrders = JsonVal.data.orders.filter(order => {
    if (order.ParentID === 0) {
        order.children = "";
        parentMap[order.pID] = order;
        return true;
    }
    return false;
});

// 3. 遍历子对象，添加到对应父对象的临时数组中
JsonVal.data.orders.forEach(order => {
    if (order.ParentID !== 0 && parentMap[order.ParentID]) {
        if (!parentMap[order.ParentID]._tempChildren) {
            parentMap[order.ParentID]._tempChildren = [];
        }
        parentMap[order.ParentID]._tempChildren.push(order);
    }
});

// 4. 将临时数组转为字符串（匹配示例的单引号格式），清理临时属性
parentOrders.forEach(parent => {
    if (parent._tempChildren) {
        parent.children = JSON.stringify(parent._tempChildren).replace(/"/g, "'");
        delete parent._tempChildren;
    } else {
        parent.children = "";
    }
});

// 5. 替换原数组为处理后的父对象数组
JsonVal.data.orders = parentOrders;

// 查看结果
console.log(JSON.stringify(JsonVal, null, 2));

代码说明 #

• 用parentMap快速定位父对象，避免嵌套循环，提升处理效率
• 先筛选父对象并初始化children，确保所有父对象都符合字段要求
• 临时属性_tempChildren用于暂存子对象，最后统一转换为字符串格式
• 替换双引号为单引号是为了匹配示例输出，若不需要标准JSON格式外的特殊处理，可去掉.replace(/"/g, "'")

内容的提问来源于stack exchange，提问作者Sahar