如何复制同名的数据？

Question

我的代码：

this.temp1.push(this.json);

for(let i=0; i<this.temp1.length; i++){
    if(this.temp1[i].name == this.json.name){       
        this.orderList[i] = this.json;
        this.DBorder[i] = this.order_json;      
    }
    else{
        this.orderList.push(this.json);
        this.DBorder.push(this.order_json);
    }
}

我的第一个输入数据：

[{"name":"Pad-Thai", "price":10,"amount":1,"total":10}]

我的第二个输入数据(有一个新的金额)：

[{"name":"Pad-Thai", "price":10,"amount":3,"total":30}]

目前的结果：

[{"name":"Pad-Thai", "price":10,"amount":3,"total":30},
{"name":"Pad-Thai", "price":10,"amount":3,"total":30}]

预期结果：

[{"name":"Pad-Thai", "price":10,"amount":3,"total":30}]

Answer 1

1. 在数组中添加新对象时，检查名称和更新是否存在其他嵌入。

  const obj1 = { "name": "Pad-Thai", "price": 10, "amount": 1, "total": 10 };         const obj2 = { "name": "Pad-Thai", "price": 10, "amount": 3, "total": 30 };         const obj3 = { "name": "Some-Other-Dish", "price": 20, "amount": 2, "total": 40 };          let temp1 = [];         function addItem(obj) {             let index = temp1.findIndex(x => x.name === obj.name);             if (index > -1) {                 temp1[index] = obj;             } else {                 temp1.push(obj);             }         }         addItem(obj1);         addItem(obj2);         addItem(obj3);         console.log('temp1 : ', temp1);

1. 如果您已经添加了相同名称的obj，则可以删除使用for循环并查找索引或减少循环

。

  const output = [         { "name": "Pad-Thai", "price": 10, "amount": 1, "total": 10 },         { "name": "Pad-Thai", "price": 10, "amount": 3, "total": 30 },         { "name": "Some-Other-Dish", "price": 20, "amount": 2, "total": 40 }     ]      let temp1 = [];     output.forEach(obj => {         let index = temp1.findIndex(x => x.name === obj.name);         if (index > -1) {             temp1[index] = obj;         } else {             temp1.push(obj);         }      });     console.log('temp1 : ', temp1);

Answer 2

​

const input1 = [{
  "name": "Pad-Thai",
  "price": 10,
  "amount": 3,
  "total": 10
}]
const input2 = [{
  "name": "Pad-Thai",
  "price": 10,
  "amount": 3,
  "total": 30
}];

function merge(existing, update, identifier) {
  const mapped = update.reduce((acc, el) => {
    return { ...acc,
      [el[identifier]]: el
    };
  }, {});

  return existing.map(el => {
    const altered = { ...el,
      ...mapped[el[identifier]]
    };
    
    delete mapped[el[identifier]];

    return altered;
  }).concat(Object.values(mapped));
}

console.log(merge(input1, input2, "name"));

​