在Javascript中推送不重复的数组并更改对象的属性值？

Question

我有一个对象，我正在推入数组，同时推入我需要限制重复项，如果属性有任何更改，则相应地更新数组？

    [{
    Id: "a134",
    Name: "Name -",
    Company: "001",
    Product :"01"
    quantity :1
    },
   {
    Id: "a135",
    Name: "Name -1",
    Company: "002",
    Product :"03"
    quantity :2  -----> (Previous event.target.name)
    },
    {
    Id: "a135",
    Name: "Name -1",
    Company: "002",
    Product :"03"
    quantity :3  ---> (current event.target.name)
    }
  ]

如果我推入数组，可能有机会更新数量如何实现以下结果

[{
        Id: "a134",
        Name: "Name -",
        Company: "001",
        Product :"01"
        quantity :1
        },
        {
        Id: "a135",
        Name: "Name -1",
        Company: "002",
        Product :"03"
        quantity :3  ---> (current event.target.name)
        }
      ]

现在我的代码是

 if(event.target.value!='')
                  {
                  
                    const searchObj = this.myList.find(({ Id,Product, Company  }) => Product === index);
                    if (searchObj)
                    {
                        console.log('searchObj',searchObj);
                       
                       resultVal = { ...searchObj, quantity:parseInt(event.target.value)}; 
                       
                       if (!this.newProductList.some(e => e.Product === resultVal.Product)) 
                        {
                         this.newProductList.push(resultVal);
                        }
                        
                       
                    }
                
                  }

Answer 1

我认为数组是错误的数据类型。我更喜欢使用map。

这当然只有在 Id 唯一的情况下才有效，因为这是最好用作键的：

const myMap = new Map([["a134",{
                               Name: "Name -",
                               Company: "001",
                               Product :"01",
                               quantity :1
                              }]]);

然后在更新数量或添加新项目之前，很容易检查项目是否已经存在。

const id = "a134"; // or "a135" for a new entry
const newItem = { Name: "Name B",
                  Company: "002",
                  Product :"012",
                  quantity :1
                  }
if(myMap.has(id)){
  const item = myMap.get(id);
  myMap.set(id, {...item, quantity: item.quantity +1})
} else {
   myMap.set(id,newItem);
}
console.log(myMap) // Map {'a134' => { Name: 'Name A', Company: '001', Product:'01', quantity: 2 } }

Answer 2

这最好通过使用不同的数据结构来解决：使用普通对象，以Id 为键：

let data = {
    "a134": {
        Id: "a134"
        Name: "Name -",
        Company: "001",
        Product: "01"
        quantity: 1

    },
    "a135": {
        Id: "a135",
        Name: "Name -1",
        Company: "002",
        Product: "03"
        quantity: 2
    },
};

更新/添加不要推送，而是设置对象键的值。例如：

// Let's say we want to add/update with this object:
let objToAdd = {
    Id: "a135",
    Name: "Name -1",
    Company: "002",
    Product: "03"
    quantity: 3
}
// ...then just do:
data[objToAdd.Id] = objToAdd;

这将更新或“插入”。在上述情况下，它将更新：

let data = {
    "a134": {
        Id: "a134"
        Name: "Name -",
        Company: "001",
        Product: "01"
        quantity: 1
    },
    "a135": {
        Id: "a135",
        Name: "Name -1",
        Company: "002",
        Product: "03"
        quantity: 3
    },
};

如果您需要数组格式，那么就这样做：

let arr = Object.values(data);

...但是尝试坚持使用数组是低效代码的保证。它只是不适合这里的工作。您应该调整您的代码以始终使用纯对象表示。您可以迭代对象中的值，可以从对象中删除项目、更新、添加等。