开发者问题收集

我在使用 FOR 将数据输入对象时遇到问题

2022-05-13
63
javascript node.js reactjs

我有一个对象，我想使用 FOR 循环遍历它 因为我想根据自己的需要更改对象

这是我的原始对象

我从 console.log() 复制了它

(7) [{…}, {…}, {…}, {…}, {…}, {…}, {…}] 

[
 {Order: 14, Address: 100101, SKU: 'CJNSXZHL', CJ Quantity: '1', Store: 'go', …}
 {SKU: 'CJNSX', CJ Quantity: '1', CJ Product Name: 'bbb', __rowNum__: 2}
 {Order: 15, Address: 100102, SKU: 'CJNSXZN', CJ Quantity: '1', Store: 'go', …}
 {SKU: 'CJNS', CJ Quantity: '1', CJ Product Name: 'ddd', __rowNum__: 4}
 {Order: 16, Address: 100103, SKU: 'CJNSX', CJ Quantity: '1', Store: 'go', …}
 {SKU: 'CJNS', CJ Quantity: '1', CJ Product Name: 'fff', __rowNum__: 6}
{Order: 17, Address: 100104, SKU: 'CJNSTX', CJ Quantity: 2, Store: 'go', …}
]

现在我想做的是检查我是否在 ORDER 中未定义 您可以看到，在第一行中，它设置在第二个 no 中，如果没有，则获取第二行中 SKU 中的值并将其插入数组中的先前位置 我将附上我编写的代码 

const arr = [];
for ( let i=0 ; i <= items.length-1;i++) {
                
            try {
            if (items[i].Order !== undefined){
                console.log(" have ",i)
                arr.push({
                    "CJ Order Number":items[i].Order,
                    "Address":items[i].Address,
                    "SKU":[items[i].SKU],
                        });
            }
            else if (items[i].Order === undefined){ 
                
                console.log("dont have ",i)
                arr[i-1].SKU.push(items[i].SKU)
                
            }
            }catch (err){
                console.log("err",i)
            }
        }  
        console.log(arr)

只在第一行中发生的情况是它成功了 但在第三次迭代中，应该进入第二行，它没有成功，我收到错误

“TypeError：无法读取属性undefined (reading 'SKU')"

而奇怪的是，他在第一行就成功了 这里是来自console.log()的代码

我把第一行打开了，这样你就能看到他输入的SKU值在下一行 

(4) [{…}, {…}, {…}, {…}]
0:
Address: 100101
CJ Order Number: 14
SKU: (2) ['CJNSXZHL', 'CJNSX']
[[Prototype]]: Object
1: {CJ Order Number: 15, Address: 100102, SKU: Array(1)}
2: {CJ Order Number: 16, Address: 100103, SKU: Array(1)}
3: {CJ Order Number: 17, Address: 100104, SKU: Array(1)}
length: 4

我也一步一步跟着 任意集成 

have  0
 1 'dont have'
 have  2
 3 'dont have'
 err 3
 have  4
 5 'dont have'
 err 5
 have  6
3个回答
let items = [{
    Order: 14,
    Address: 100101,
    SKU: 'CJNSXZHL',
    'CJ Quantity': '1',
    Store: 'go',
  },
  {
    SKU: 'CJNSX',
    'CJ Quantity': '1',
    'CJ Product Name': 'bbb',
    __rowNum__: 2
  },
  {
    Order: 15,
    Address: 100102,
    SKU: 'CJNSXZN',
    'CJ Quantity': '1',
    Store: 'go',
  },
  {
    SKU: 'CJNS',
    'CJ Quantity': '1',
    'CJ Product Name': 'ddd',
    __rowNum__: 4
  },
  {
    Order: 16,
    Address: 100103,
    SKU: 'CJNSX',
    'CJ Quantity': '1',
    Store: 'go'
  },
  {
    SKU: 'CJNS',
    'CJ Quantity': '1',
    'CJ Product Name': 'fff',
    __rowNum__: 6
  },
  {
    Order: 17,
    Address: 100104,
    SKU: 'CJNSTX',
    'CJ Quantity': 2,
    Store: 'go'
  },
];

const arr = [];

for (let i = 0; i <= items.length - 1; i++) {

  if (items[i].Order) {
    arr.push({
      'CJ Order Number': items[i].Order,
      Address: items[i].Address,
      SKU: [items[i].SKU],
    });
  } else {
    arr[arr.length - 1].SKU.push(items[i].SKU); // the last element
  }
}

console.log(arr);

Try this.
Nizamuddin Shaikh
2022-05-15

希望这是您要做的，您可以尝试这样做，但可能会有更好的解决方案。 

const arr = [];
  const items = [
    {
      Order: 14,
      Address: 100101,
      SKU: "CJNSXZHL",
      CJ_Quantity: "1",
      Store: "go",
    },
    { SKU: "CJNSX", CJ_Quantity: "1", CJ_Product_Name: "bbb", __rowNum__: 2 },
    {
      SKU: "CJNSXZN",
      Order: 15,
      Address: 100102,
      CJ_Quantity: "1",
      Store: "go",
    },
    { SKU: "CJNS", CJ_Quantity: "1", CJ_Product_Name: "ddd", __rowNum__: 4 },
    { Order: 16, Address: 100103, SKU: "CJNSX", CJ_Quantity: "1", Store: "go" },
    { SKU: "CJNS", CJ_Quantity: "1", CJ_Product_Name: "fff", __rowNum__: 6 },
    { Order: 17, Address: 100104, SKU: "CJNSTX", CJ_Quantity: 2, Store: "go" },
  ];
  for (let i = 0, j = 1; i <= items.length - 1; i++) {
    try {
      if (items[i].Order) {
        arr.push({
          "CJ Order Number": items[i].Order,
          Address: items[i].Address,
          SKU: [items[i].SKU],
        });
      } else {
        arr[j-1].SKU.push(items[i].SKU);
        j++;
      }
    } catch (err) {
      console.log("err", err);
    }
  }
      console.log(arr);
Abderrahmen Mhemed
2022-05-13

您可以使用 reduce 

const data = [{
    Order: 14,
    Address: 100101,
    SKU: 'CJNSXZHL',
    'CJ Quantity': '1',
    Store: 'go'
  },
  {
    SKU: 'CJNSX',
    'CJ Quantity': '1',
    'CJ Product Name': 'bbb',
    __rowNum__: 2
  },
  {
    Order: 15,
    Address: 100102,
    SKU: 'CJNSXZN',
    'CJ Quantity': '1',
    Store: 'go'
  },
  {
    SKU: 'CJNS',
    'CJ Quantity': '1',
    'CJ Product Name': 'ddd',
    __rowNum__: 4
  },
  {
    Order: 16,
    Address: 100103,
    SKU: 'CJNSX',
    'CJ Quantity': '1',
    Store: 'go'
  },
  {
    SKU: 'CJNS',
    'CJ Quantity': '1',
    'CJ Product Name': 'fff',
    __rowNum__: 6
  },
  {
    Order: 17,
    Address: 100104,
    SKU: 'CJNSTX',
    'CJ Quantity': 2,
    Store: 'go'
  }
]

const result = data.reduce((res, item) => {

  if (item.Order) {
    
    return [...res, {...item, SKU:[]}]
  }
  const lastOrder = res[res.length - 1]
  res[res.length - 1].SKU = [...(lastOrder.SKU || []), item]
  return res

}, [])

console.log(result)
轻松完成此操作
R4ncid
2022-05-13