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法律研究對 JavaScript 陣列進行分組
假設我們有一個如下 JavaSCript 陣列 −
const data = [
{
"dataId": "1",
"tableName": "table1",
"column": "firstHeader",
"rows": [
"a","b","c"
]
},
{
"dataId": "2",
"tableName": "table1",
"column": "secondHeader",
"rows": [
"d","e","f",
]
}, {
"dataId": "3",
"tableName": "table2",
"column": "aNewFirstHeader",
"rows": [
1,2,3
]
}
];我們需要編寫一個 JavaScript 函式，該函式位於其中一個數組中。該函式應該基於原始陣列構建一個新的分組物件陣列。
分組陣列應將用於各個唯一“tableName”物件的的資料包含在自己的物件中。
因此，最終，輸出應如下所示 −
const output = [
{
"tableName": "table1",
"column": ["firstHeader", "secondHeader"],
"rows": [["a","b","c"], ["d","e","f"]]
},
{
"tableName": "table2",
"column": ["aNewFirstHeader"],
"rows": [[1,2,3]]
}
];示例
const arr = [
{
"dataId": "1",
"tableName": "table1",
"column": "firstHeader",
"rows": [ "val","b","c" ]
},
{
"dataId": "2",
"tableName": "table1",
"column": "secondHeader",
"rows": [
"d","e","f",
]
},
{
"dataId": "3",
"tableName": "table2",
"column": "aNewFirstHeader",
"rows": [
1,2,3
]
}
];
const groupArray = (arr = []) => {
const res = arr.reduce((obj => (acc, val) => {
let item = obj.get(val.tableName);
if (!item) {
item = {
tableName: val.tableName, column: [], rows: []
}
obj.set(val.tableName, item); acc.push(item);
};
item.column.push(val.column); item.rows.push(val.rows);
return acc;
})(new Map), []);
return res;
};
console.log(JSON.stringify(groupArray(arr), undefined, 4));輸出
控制檯中輸出的結果為 −
[
{
"tableName": "table1",
"column":
[
"firstHeader",
"secondHeader"
],
"rows": [
[
"val", "b", "c"
],
[
"d", "e", "f"
]
]
}, {
"tableName": "table2",
"column": [
"aNewFirstHeader"
],
"rows": [
[
1, 2, 3
]
]
}
]
更新時間： 2020 年 11 月 23 日
273 次瀏覽
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