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法律研究複雜的 JavaScript 陣列分組
假設我們有一個如下所示的物件陣列 -
const arr = [
{userId: "3t5bsFB4PJmA3oTnm", from: 1, to: 6},
{userId: "3t5bsFB4PJmA3oTnm", from: 7, to: 15},
{userId: "3t5bsFB4PJmA3oTnm", from: 172, to: 181},
{userId: "3t5bsFB4PJmA3oTnm", from: 182, to: 190}
];我們要求編寫一個 JavaScript 函式，該函式取入這樣的一個數組。該函式應根據 “from” 和 “to” 屬性將重疊的物件分組到一個物件中，如下所示 -
const output = [
{userId: "3t5bsFB4PJmA3oTnm", from: 1, to: 15},
{userId: "3t5bsFB4PJmA3oTnm", from: 172, to: 190}
];示例
const arr = [
{userId: "3t5bsFB4PJmA3oTnm", from: 1, to: 6},
{userId: "3t5bsFB4PJmA3oTnm", from: 7, to: 15},
{userId: "3t5bsFB4PJmA3oTnm", from: 172, to: 181},
{userId: "3t5bsFB4PJmA3oTnm", from: 182, to: 190}
];
const groupByDuration = (arr = []) => {
const result = arr.reduce((acc, val) => {
let last = acc[acc.length - 1] || {};
if (last.userId === val.userId && last.to + 1 === val.from) {
last.to = val.to; } else {
acc.push({ userId: val.userId, from: val.from, to: val.to });
}
return acc;
}, []);
return result;
}
console.log(groupByDuration(arr));輸出
控制檯中的輸出為 -
[
{ userId: '3t5bsFB4PJmA3oTnm', from: 1, to: 15 },
{ userId: '3t5bsFB4PJmA3oTnm', from: 172, to: 190 }
]
更新於: 2020-11-21
148 次瀏覽
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