如何 map 我从 api 调用 usestate 变量获得的 object 数组所需的数据

Question

[
    {
        cases: {new: '+44', active: 216, critical: 1, recovered: 15364, 1M_pop: '35323', …}
        continent: "Asia"
        country: "Brunei"
        day: "2022-01-10"
        deaths: {new: null, 1M_pop: '221', total: 98}
        population: 443851
        tests: {1M_pop: '1562743', total: 693625}
        time: "2022-01-10T16:15:04+00:00"
    },
    { 
        cases: {new: '+2', active: 4, critical: null, recovered: 20, 1M_pop: '34', …}
        continent: "Oceania"
        country: "Solomon-Islands"
        day: "2022-01-10"
        deaths: {new: null, 1M_pop: null, total: null}
        population: 711920
        tests: {1M_pop: '6321', total: 4500}
        time: "2022-01-10T16:15:04+00:00"
    }
]

像这样，我有 236 个 object 数组，但我只想要它的少数数据，如国家、大陆、总案例等，并将其存储在 usetate 变量中，该变量将是 object 的数组，但它只会有这个数据

Answer 1

let response = [
    {
        cases: { new: '+44', active: 216, critical: 1, recovered: 15364, 1M_pop: '35323', … }
        continent: "Asia"
        country: "Brunei"
        day: "2022-01-10"
        deaths: { new: null, 1M_pop: '221', total: 98 }
        population: 443851
        tests: { 1M_pop: '1562743', total: 693625 }
        time: "2022-01-10T16:15:04+00:00"
    },
    {
        cases: { new: '+2', active: 4, critical: null, recovered: 20, 1M_pop: '34', … }
        continent: "Oceania"
        country: "Solomon-Islands"
        day: "2022-01-10"
        deaths: { new: null, 1M_pop: null, total: null }
        population: 711920
        tests: { 1M_pop: '6321', total: 4500 }
        time: "2022-01-10T16:15:04+00:00"
    }
];
let mappedResponse = response.map(obj => {
    const { country, continent } = obj;
    return {
        country, 
        continent
    }
})

Answer 2

如果我理解得很好，您有一个包含 236 个条目的数组。 如果这是正确的，您可以执行以下操作：

const results = [
    {
        cases: {new: '+44', active: 216, critical: 1, recovered: 15364, 1M_pop: '35323', …}
        continent: "Asia"
        country: "Brunei"
        day: "2022-01-10"
        deaths: {new: null, 1M_pop: '221', total: 98}
        population: 443851
        tests: {1M_pop: '1562743', total: 693625}
        time: "2022-01-10T16:15:04+00:00"
    },
    { 
        cases: {new: '+2', active: 4, critical: null, recovered: 20, 1M_pop: '34', …}
        continent: "Oceania"
        country: "Solomon-Islands"
        day: "2022-01-10"
        deaths: {new: null, 1M_pop: null, total: null}
        population: 711920
        tests: {1M_pop: '6321', total: 4500}
        time: "2022-01-10T16:15:04+00:00"
    }
];

const newArray = results.map(m => {
   return { country: m.country, cases: m.cases }
})