如何從數組對象中添加兩個鍵值並在第一個鍵中更新？

Question

我有兩個對象的數組：

let abc = [
  {amount: 1000, rate: 4},
  {amount: 100,  rate: 2},
  {amount: 700,  rate: 1}
];

我想乘以amount * rate並更新amount鍵。

預期產量：

let output = [
  {amount: 4000, rate: 4},
  {amount: 200,  rate: 2},
  {amount: 700,  rate: 1}
];

Answer 1

您可以簡單地使用.map() ：

 let data = [{amount: 1000, rate: 4}, {amount: 100, rate: 2},{amount: 700, rate: 1}]; let result = data.map(o => ({...o, amount: o.amount * o.rate})); console.log(result); 

 .as-console-wrapper { max-height: 100% !important; top: 0; } 

Answer 2

使用Array.prototype.map() ：

  let abc = [{amount: 1000, rate: 4}, {amount: 100, rate: 2}, {}, {amount: 700, rate: 1}] abc.map(x => { if(!x.amount || !x.rate){ // account for empty objects return x; } return {...x, amount: x.amount * x.rate} }); 

Answer 3

let abc = [{amount: 1000, rate: 4}, {amount: 100, rate: 2},{amount: 700, rate: 1}]
var output = abc.map(field => {
field.amount = field.amount * field.rate
return field
})
console.log(output)

Answer 4

如果您不想創建新的數組，則可以使用forEach。

 let abc = [ {amount: 1000, rate: 4}, {amount: 100, rate: 2}, {amount: 700, rate: 1} ]; abc.forEach(item => item.amount = item.amount * item.rate) console.log(abc)