JavaScript数据转换

Question

如何把req的数组转换为res

        const req = [
    { dates: "2023-02-02", index: "1", total: 3 },
    { dates: "2023-02-02", index: "2", total: 0 },
    { dates: "2023-02-03", index: "1", total: 6 },
    { dates: "2023-02-03", index: "2", total: 7 },
    { dates: "2023-02-03", index: "3", total: 3 },
    { dates: "2023-02-03", index: "4", total: 5 },
    { dates: "2023-02-04", index: "2", total: 2 },
    { dates: "2023-02-04", index: "3", total: 7 },
    { dates: "2023-02-04", index: "4", total: 1 },
    { dates: "2023-02-04", index: "5", total: 4 },
    { dates: "2023-02-05", index: "4", total: 3 },
    { dates: "2023-02-05", index: "5", total: 2 },
    { dates: "2023-02-05", index: "6", total: 7 },
    { dates: "2023-02-05", index: "7", total: 1 },
    { dates: "2023-02-06", index: "1", total: 7 },
    { dates: "2023-02-06", index: "2", total: 4 },
    { dates: "2023-02-06", index: "5", total: 3 },
    { dates: "2023-02-06", index: "6", total: 11 },
    { dates: "2023-02-07", index: "3", total: 123 },
    { dates: "2023-02-07", index: "4", total: 7 },
    { dates: "2023-02-07", index: "6", total: 99 },
    { dates: "2023-02-07", index: "7", total: 2 },
];

let res=[
    { index: "1", data: [3, 6, 0, 0, 7, 0] },
    { index: "2", data: [0, 7, 2, 0, 4, 0] },
    { index: "3", data: [0, 3, 7, 0, 0, 123] },
    { index: "4", data: [0, 5, 1, 3, 0, 7] },
    { index: "5", data: [0, 0, 4, 2, 3, 0] },
    { index: "6", data: [0, 0, 0, 7, 11, 99] },
    { index: "7", data: [0, 0, 0, 1, 0, 2] },
];

Answer 1

    const req = [
        { dates: "2023-02-02", index: "1", total: 3 },
        { dates: "2023-02-02", index: "2", total: 0 },
        { dates: "2023-02-03", index: "1", total: 6 },
        { dates: "2023-02-03", index: "2", total: 7 },
        { dates: "2023-02-03", index: "3", total: 3 },
        { dates: "2023-02-03", index: "4", total: 5 },
        { dates: "2023-02-04", index: "2", total: 2 },
        { dates: "2023-02-04", index: "3", total: 7 },
        { dates: "2023-02-04", index: "4", total: 1 },
        { dates: "2023-02-04", index: "5", total: 4 },
        { dates: "2023-02-05", index: "4", total: 3 },
        { dates: "2023-02-05", index: "5", total: 2 },
        { dates: "2023-02-05", index: "6", total: 7 },
        { dates: "2023-02-05", index: "7", total: 1 },
        { dates: "2023-02-06", index: "1", total: 7 },
        { dates: "2023-02-06", index: "2", total: 4 },
        { dates: "2023-02-06", index: "5", total: 3 },
        { dates: "2023-02-06", index: "6", total: 11 },
        { dates: "2023-02-07", index: "3", total: 123 },
        { dates: "2023-02-07", index: "4", total: 7 },
        { dates: "2023-02-07", index: "6", total: 99 },
        { dates: "2023-02-07", index: "7", total: 2 },
    ];
    let keys = Array.from(new Set(req.map(i => i.index)));//得到唯一index的值
    let dates = Array.from(new Set(req.map(i => i.dates)));//得到唯一dates的值
    let res = keys.map(index => {
        let data = dates.map(date => {
            let item = req.find(i => i.dates == date && i.index == index);//找到index和dates一样的项
            return item ? item.total : 0;//找不到发返回0，否则返回total属性
        })
        return { index, data };
    })
    console.log(res)
    /*
let res=[
    { index: "1", data: [3, 6, 0, 0, 7, 0] },
    { index: "2", data: [0, 7, 2, 0, 4, 0] },
    { index: "3", data: [0, 3, 7, 0, 0, 123] },
    { index: "4", data: [0, 5, 1, 3, 0, 7] },
    { index: "5", data: [0, 0, 4, 2, 3, 0] },
    { index: "6", data: [0, 0, 0, 7, 11, 99] },
    { index: "7", data: [0, 0, 0, 1, 0, 2] },
];*/