如果为其中一个重复项设置了值，则如何从数组中删除重复项，否则为空(javascript/typescript)

yqkkidmi 于 2023-01-03 发布在 TypeScript

关注(0)|答案(2)|浏览(95)

我需要从javascript（typescript）的数组中删除重复的或空的值（集合），如果在同一天有非空值的数据，如果所有的值（集合）在那天都是空的，我们应该保留一个值。

示例：

0: (2) ['2022-12-05', null]   ---> Remove due to "Reason 1"
1: (2) ['2022-12-05', 2695.923015841]   ---> Remain because it has a y value (on 5 Dec)
2: (2) ['2022-12-05', null]   ---> Remove due to "Reason 1"
3: (2) ['2022-12-05', null]   ---> Remove due to "Reason 1"

4: (2) ['2022-12-12', null]   ---> Remove due to "Reason 1"
5: (2) ['2022-12-12', 3984.864626441]   ---> Remain because it has a y value (on 12 Dec)
6: (2) ['2022-12-12', null]   ---> Remove due to "Reason 1"
7: (2) ['2022-12-12', null]   ---> Remove due to "Reason 1"

8: (2) ['2022-12-19', null]   ---> Remove due to "Reason 2"
9: (2) ['2022-12-19', null]   ---> Remove due to "Reason 2"
10: (2) ['2022-12-19', null]   ---> Remove due to "Reason 2"
11: (2) ['2022-12-19', null]   ---> Remain because no y value on this date

- 原因1**：数组的这个成员应该被删除，因为在同一个日期有一个空值（在x中指定）。

0: (2) [x: Date, y: value]

- 原因2**：这个成员应该被删除，因为我们有4个相同值的重复对象，我们只需要其中的一个。

预期结果：

它将是一个具有3个值（集）的数组。

0: (2) ['2022-12-05', 2695.923015841]   ---> Remain because it has a y value 
1: (2) ['2022-12-12', 3984.864626441]   ---> Remain because it has a y value 
2: (2) ['2022-12-19', null]   ---> Remain because no y value on this date

typescript

来源：https://stackoverflow.com/questions/74950525/how-to-remove-duplicates-from-array-if-value-set-for-one-of-the-duplicates-else

2条答案

按热度按时间

gcxthw6b1#

您可以使用单个循环来缩减数组，并检查date

const
    data = [['2022-12-05', null], ['2022-12-05', 2695.923015841], ['2022-12-05', null], ['2022-12-05', null], ['2022-12-12', null], ['2022-12-12', 3984.864626441], ['2022-12-12', null], ['2022-12-12', null], ['2022-12-19', null], ['2022-12-19', null], ['2022-12-19', null], ['2022-12-19', null]],
    result = data.reduce((r, [date, value], i, a) => {
        if (i && a[i - 1][0] === date) r.at(-1)[1] ||= value;
        else r.push([date, value]);
        return r;
    }, []);

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

赞(0）回复(0）举报 2023-01-03

t1rydlwq2#

const arr = [
  ['2022-12-05', null],
  ['2022-12-05', 2695.923015841],
  ['2022-12-05', null],
  ['2022-12-05', null],
  ['2022-12-12', null],
  ['2022-12-12', 3984.864626441],
  ['2022-12-12', null],
  ['2022-12-12', null],
  ['2022-12-19', null],
  ['2022-12-19', null],
  ['2022-12-19', null],
  ['2022-12-19', null],
];

const newArr = [...new Set(arr.map(item => item[0]))].map(item => {
  const findVal = arr.find(_item => _item[0] === item && _item[1]);
  if (findVal) return findVal;
  return [item, null];
});

console.log(newArr);

赞(0）回复(0）举报 2023-01-03

我来回答

如果为其中一个重复项设置了值，则如何从数组中删除重复项，否则为空(javascript/typescript)

示例：

预期结果：

2条答案

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