我怎样才能 map 并返回反应中的第一个和最后一个元素？

Question

I am having problem with login return first element and last element:

Here is my array of object:

0:
pointAmountMax: 99999
pointAmountMin: 1075
rateCode: ['INAINOW']
roomPoolCode: "ZZAO"
[[Prototype]]: Object
1:
pointAmountMax: 99999
pointAmountMin: 850
rateCode: ['INAINOJ']
roomPoolCode: "TOGA"
[[Prototype]]: Object
length: 2

How can I map through the array and return the pointAmountMin smaller number first?

So in this case I want to achieve something like this in my front end

return <p>850 - 1075</p>

Answer 1

To get the required output first you will need to sort the array of object in ascending order related to the property pointAmountMin.

let arrayOfObj = [
    {
        pointAmountMax: 99999,
        pointAmountMin: 1075,
        rateCode: ['INAINOW'],
        roomPoolCode: "ZZAO",
    },
    {
        pointAmountMax: 99999,
        pointAmountMin: 850,
        rateCode: ['INAINOJ'],
        roomPoolCode: "TOGA",
    }
];

arrayOfObj.sort((a, b) => {
    return a.pointAmountMin - b.pointAmountMin
})
console.log(arrayOfObj)

Then collect only pointAmountMin values in an array.

const filteredResult = arrayOfObj.map(() => {
  return pointAmountMin
})

You have list of all pointAmountMin property values in ascending order (minimum first) Now you can show it on UI in your required format

<p>filteredResult.join(' - ')</p>

Answer 2

Use sort() and then return the desired HTML

 function App(){ const myArray = [ { pointAmountMax: 99999, pointAmountMin: 1075, somethingElse: null, }, { pointAmountMax: 99999, pointAmountMin: 650, somethingElse: null, }, { pointAmountMax: 99999, pointAmountMin: 975, somethingElse: null, } ] const getRange = (data) => { let sorted = data.sort((a,b) => {a.pointAmountMin - b.pointAmountMin}) return [ <p key={Math.random()}> {sorted[0].pointAmountMin} - {sorted.pop().pointAmountMin} </p> ] } return <span>{getRange(myArray)}</span>; } ReactDOM.render(<App/>, document.getElementById("root"));

 <script crossorigin src="https://unpkg.com/react@16/umd/react.development.js"></script> <script crossorigin src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script> <div id="root"/>