如何使用 SetInterval 在函数中更改此状态变量？

Question

I've got this function that takes in a data set (JSON) and returns an object. But I want to be able to change this data set every 2 seconds. So I need to somehow change that argument every 2 seconds and then call it so a different object is rendered every two seconds

The Function:

 const [dataset, setDataSet] = useState(season19) const stats = [{"stat" :"points" , ppg: ""}, {"stat": "rebounds", ast: ""}, {"stat": "assists", reb: ""}] const sortedData = (dataset, nums) => { const finalData = nums.map((stat) => { if(Object.values(stat).includes("points")){ return{ ...stat, ppg: dataset[0].pts } } else if(Object.values(stat).includes("rebounds")){ return{ ...stat, reb:dataset[0].reb } } else if(Object.values(stat).includes("assists")){ return{ ...stat, ast:dataset[0].ast } } }) return finalData }

and im calling it like so:

sortedData(dataset,stats)

The other two data sets are season20 and season21

How would I approach this?

What I tried

I put this into the sortedData function ,

 setInterval(() => {
        setDataset(season20)
      }, 2000)

it works but obviously it only changes to season20, how can I do it so it changes to season21 also

Answer 1

You need use useEffect and put inside setInterval for every 2s state should be change. Component should be look about that. live code

import "./styles.css";
import { useState, useEffect } from "react";

export default function App() {
 const [season, setSeason] = useState("season19");

 useEffect(() => {
  const next = setInterval(() => {
    let num = Number(season.substring(6, 9));
    let str = `season${++num}`;

    if (num > 25) return clearInterval(next); // remove setInterval after N-times 

    setSeason(str);
  }, 2000);

    return () => clearInterval(next); // remove setInterval after comp unmounted 

 }, [season]);

 return (
   <div className="App">
     <h1>Hello CodeSandbox</h1>
     <h2>{season}</h2>
   </div>
 );
}