如何从javascript中的数组中删除最后一个索引元素？ [复制]

Posted 2023-02-23

【中文标题】如何从javascript中的数组中删除最后一个索引元素？ [复制]

【英文标题】：How to remove last index element from array in javascript? [duplicate]

【发布时间】：2021-11-09 12:26:03

【问题描述】：

我有一个数组

0: Premium: '18', ChangeType: 'REW', description: 'Replaced by Agent', TransDate: '2021-09-14 15:15:11', EffectiveDate: '2021-09-14', …
1: Premium: '19', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 15:10:45', EffectiveDate: '2021-09-14', …
2: Premium: '3', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 15:10:08', EffectiveDate: '2021-09-14', …
3: Premium: '19', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 15:09:43', EffectiveDate: '2021-09-14', …
4: Premium: '19', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 15:08:21', EffectiveDate: '2021-09-14', …
5: Premium: '19', ChangeType: 'XLN', description: 'ewqwe', TransDate: '2021-09-14 15:07:53', EffectiveDate: '2021-09-15', …
6: Premium: '198', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 15:01:01', EffectiveDate: '2021-09-14', …
7: Premium: '15', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 15:00:14', EffectiveDate: '2021-09-14', …
8: Premium: '19', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 14:59:08', EffectiveDate: '2021-09-14', …
9: Premium: '13', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 14:58:32', EffectiveDate: '2021-09-14', …
10: Premium: '11', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 14:57:14', EffectiveDate: '2021-09-14', …
11: Premium: '12', ChangeType: 'PCH', description: 'wewqe', TransDate: '2021-09-14 14:44:13', EffectiveDate: '2021-09-14', …
12: EntryDate: '9/14/2021', EffectiveDate: '2021-09-14', ChangeType: 'XLN', Premium: '19', description: 'Replaced by Agent', …

我想从数组中删除最后一行。我使用了 pop() 函数，但它只返回最后一条记录，而不是返回除最后一条以外的完整数组。

另外，我尝试过如下拼接方法。

policy_info.transactions.splice(policy_info.transactions.length - 1);

我无法得到结果。谁能告诉我使用数组的什么方法来达到结果？

我想要的结果是

0: Premium: '18', ChangeType: 'REW', description: 'Replaced by Agent', TransDate: '2021-09-14 15:15:11', EffectiveDate: '2021-09-14', …
    1: Premium: '19', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 15:10:45', EffectiveDate: '2021-09-14', …
    2: Premium: '3', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 15:10:08', EffectiveDate: '2021-09-14', …
    3: Premium: '19', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 15:09:43', EffectiveDate: '2021-09-14', …
    4: Premium: '19', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 15:08:21', EffectiveDate: '2021-09-14', …
    5: Premium: '19', ChangeType: 'XLN', description: 'ewqwe', TransDate: '2021-09-14 15:07:53', EffectiveDate: '2021-09-15', …
    6: Premium: '198', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 15:01:01', EffectiveDate: '2021-09-14', …
    7: Premium: '15', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 15:00:14', EffectiveDate: '2021-09-14', …
    8: Premium: '19', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 14:59:08', EffectiveDate: '2021-09-14', …
    9: Premium: '13', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 14:58:32', EffectiveDate: '2021-09-14', …
    10: Premium: '11', ChangeType: 'XLN', description: 'Replaced by Agent', TransDate: '2021-09-14 14:57:14', EffectiveDate: '2021-09-14', …
    11: Premium: '12', ChangeType: 'PCH', description: 'wewqe', TransDate: '2021-09-14 14:44:13', EffectiveDate: '2021-09-14', …

【问题讨论】：

这能回答你的问题吗？ Remove last item from array

@victorfau 否 它对我没有帮助，它只返回这样的一行 0: EntryDate: '9/14/2021', EffectiveDate: '2021-09-14', ChangeType: 'XLN '，Premium：'11'，描述：'被代理替换'，...

pop 返回最后一个条目并就地修改数组。

@Alnitak 是的，pop 只会返回最后一个条目，但我想删除最后一个条目。所以它没有帮助。

@SunilSethi 不，它还会删除最后一个条目

【参考方案1】：

使用array.pop()，https://developer.mozilla.org/en-US/docs/Web/javascript/Reference/Global_Objects/Array/pop

这将从使用此方法的数组中删除最后一项并返回已删除的项。

let array = [1,2,3];
let popper = array.pop(); // will be the removed value if you need it
console.log(array); // will log the array after the pop so [1,2]

【讨论】：

但在我的情况下它只返回，0: EntryDate: '9/14/2021', EffectiveDate: '2021-09-14', ChangeType: 'XLN', Premium: '19' , 描述: '被代理替换', ... 我需要除此之外的其余条目。

@SunilSethi splice 返回一个包含已删除元素的数组。 pop 只返回被移除的元素。所以你不可能得到0: … 和pop。

@SunilSethi 在阵列上使用pop 后，再次尝试访问阵列并查看有多少条目。您正在访问 pop 方法的返回值，此时您应该在使用 pop

后查看数组

@Pauliecode 是的，你是对的。那是我犯的错误。现在我得到了想要结果的数组