如何从 json 中分离键和值，并在反应中使用 useState 挂钩将其存储在数组中

Question

function Graph() {
  const [tcases, setCases] = useState([]);
  const [recovered, setRecovered] = useState([]);
  const [deaths, setDeaths] = useState([]);
  useEffect(() => {
    axios
      .get("https://disease.sh/v3/covid-19/historical/all?lastdays=all")
      .then((res) => {
        setCases(Object.values(res.data.cases));
        setRecovered(Object.values(res.data.recovered)));
        setDeaths(Object.values(res.data.deaths)));
      })
      .catch((err) => {
        console.log(err);
      });
  }, []);

我试过上面的代码..它说病例、康复和死亡未定义

API 使用：点击这里查看 api我想要这样..请帮助:)

   tcases=[555,654,941...........]

   recovered=[17,18,26.........]

    deaths=[28,30,36...........]

谢谢！

Answer 1

function Graph() {
  const [tcases, setCases] = useState([]);
  const [recovered, setRecovered] = useState([]);
  const [deaths, setDeaths] = useState([]);
  const [date, setDate] = useState([]);
  useEffect(() => {
    axios
      .get("https://disease.sh/v3/covid-19/historical/all?lastdays=all")
      .then(res => {
        setCases(JSON.parse(JSON.stringify(Object.values(res.data.cases))));
        setDeaths(JSON.parse(JSON.stringify(Object.values(res.data.deaths))));
        setRecovered(JSON.parse(JSON.stringify(Object.values(res.data.recovered))));
        
      })
      .catch(err => {
        console.log(err);
      });
  }, []);

JSON.stringify 返回一个字符串。为了以数组格式存储它，我们必须使用 JSON.parse 返回一个 object。