Question

我想知道如何在javascript中更新对象数组。

如何使用示例对象作为函数的参数发送来更新original_sample并执行如图所示的计算

在这里，如何在单个函数中执行不同的计算<app-card> <h2>New child I passed</h2> <p>And another one</p> </app-card>和with payfee并更新对象

Gotstuck及其在javascript中的操作。

without payfee

// update the original_sample with sample2 values
var res = getValue(original_sample, sample2);
// update the original_sample with sample3 values
var res = getValue(original_sample, sample3);
function getValue(original, sample){
return original.map(({ fee, rate, ...others }) => ({
    id: 'trans'
    amount: amount,
    fee: +fee,
    rate: +rate,
    targetamount: (amount-fee)*rate
  }))
}

//inputs
var original_sample= [{
     id: "trans",
     fee: 1,
     rate: 2.2,
     amount:100,
  }]
//passed as input to update original_sample
var sample2 = [{
   id: "trans",
   fee: 2,
   rate: 4.0,
   payfee: 1%,
   amount: 100,
  }]
//passed as input to update original_sample
var sample3 =[{
 id: "trans",
 fee: 1,
 rate: 1.0,
 amount: 100
   }]

Answer 1

由于每个数组中只有一个对象，因此我要么完全放弃使用数组，要么在每次需要做的事情时都提取对象。例如这样的

function getValue(orig, update) {
    var obj = orig[0] = Object.assign({}, update[0]);
    if ("payfee" in obj) obj.payfee = parseInt(obj.payfee);
    obj.targetamount = (obj.amount-obj.fee) * (1 - (obj.payfee||0)/100) * obj.rate;
}

// Demo:
var original_sample = [{id: "trans", fee: 1, rate: 2.2, amount:100}];
var sample2 = [{id: "trans", fee: 2, rate: 4.0, payfee: "1%", amount: 100}];
var sample3 = [{id: "trans", fee: 1, rate: 1.0, amount: 100}];

getValue(original_sample, sample2);
console.log(original_sample);
getValue(original_sample, sample3);
console.log(original_sample);

Answer 2

使用Array.concat()合并数组，然后将合并后的数组简化为一个对象，方法是始终获取具有相同id的最后一个对象并计算targetAmount。用Object.values()转换回数组。

const getValue = (original, sample) =>
  Object.values(
    original.concat(sample)
    .reduce((r, o) => ({
      ...r,
      [o.id]: {
        ...o,
        targetamount: (o.amount - o.fee) * o.rate
      }
    })
    , {})
  )

const original_sample = [{"id":"trans","fee":1,"rate":2.2,"amount":100}]
const sample2 = [{"id":"trans","fee":2,"rate":4,"payfee":0.01,"amount":100}]
const sample3 = [{"id":"trans","fee":1,"rate":1,"amount":100}]

const originalAnd2 = getValue(original_sample, sample2)
const original2And3 = getValue(originalAnd2, sample3)

console.log(originalAnd2);

console.log(original2And3);

如何在javascript中更新嵌套对象数组

2 个答案: