如何从数组对象中添加两个键值并在第一个键中更新？

Question

I am having an array of two objects:

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

I want to multiply amount * rate and update in amount key.

Expected output:

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

Answer 1

You can simply use .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); 

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Answer 2

Use 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

you can use forEach, If you don't want to create a new Array.

 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)