如何在javascript中通过id从对象数组中获取唯一数据

Question

你好，我需要帮助，我正试图获得唯一的数据从对象的数组id在JavaScript中我无法获取它下面是我的数组

[
{id: 408, customer_id: 2, bill_no: 381, bill_period: 'weekly', from_date: '2021-10-10'}
{id: 409, customer_id: 3, bill_no: 382, bill_period: 'weekly', from_date: '2021-10-10'}
{id: 410, customer_id: 4, bill_no: 383, bill_period: 'weekly', from_date: '2021-10-10'}
{id: 411, customer_id: 6, bill_no: 384, bill_period: 'weekly', from_date: '2021-10-10'}
{id: 412, customer_id: 7, bill_no: 385, bill_period: 'weekly', from_date: '2021-10-10'}
{id: 413, customer_id: 8, bill_no: 386, bill_period: 'weekly', from_date: '2021-10-10'}
{id: 414, customer_id: 9, bill_no: 387, bill_period: 'weekly', from_date: '2021-10-10'}
{id: 387, customer_id: 2, bill_no: 360, bill_period: 'weekly', from_date: '2021-10-03'}
{id: 388, customer_id: 3, bill_no: 361, bill_period: 'weekly', from_date: '2021-10-03'}
{id: 389, customer_id: 4, bill_no: 362, bill_period: 'weekly', from_date: '2021-10-03'}
{id: 390, customer_id: 6, bill_no: 363, bill_period: 'weekly', from_date: '2021-10-03'}
{id: 391, customer_id: 7, bill_no: 364, bill_period: 'weekly', from_date: '2021-10-03'}
{id: 392, customer_id: 8, bill_no: 365, bill_period: 'weekly', from_date: '2021-10-03'}
{id: 393, customer_id: 9, bill_no: 366, bill_period: 'weekly', from_date: '2021-10-03'}
{id: 380, customer_id: 2, bill_no: 353, bill_period: 'weekly', from_date: '2021-09-26'}
{id: 381, customer_id: 3, bill_no: 354, bill_period: 'weekly', from_date: '2021-09-26'}
{id: 382, customer_id: 4, bill_no: 355, bill_period: 'weekly', from_date: '2021-09-26'}
{id: 383, customer_id: 6, bill_no: 356, bill_period: 'weekly', from_date: '2021-09-26'}
{id: 384, customer_id: 7, bill_no: 357, bill_period: 'weekly', from_date: '2021-09-26'}
{id: 385, customer_id: 8, bill_no: 358, bill_period: 'weekly', from_date: '2021-09-26'}
{id: 386, customer_id: 9, bill_no: 359, bill_period: 'weekly', from_date: '2021-09-26'}
]

我想要的唯一数据从上面的数组customer_id与他们的最新id，我想要的结果像下面的代码

[
{id: 408, customer_id: 2, bill_no: 381, bill_period: 'weekly', from_date: '2021-10-10'}
{id: 409, customer_id: 3, bill_no: 382, bill_period: 'weekly', from_date: '2021-10-10'}
{id: 410, customer_id: 4, bill_no: 383, bill_period: 'weekly', from_date: '2021-10-10'}
{id: 411, customer_id: 6, bill_no: 384, bill_period: 'weekly', from_date: '2021-10-10'}
{id: 412, customer_id: 7, bill_no: 385, bill_period: 'weekly', from_date: '2021-10-10'}
{id: 413, customer_id: 8, bill_no: 386, bill_period: 'weekly', from_date: '2021-10-10'}
{id: 414, customer_id: 9, bill_no: 387, bill_period: 'weekly', from_date: '2021-10-10'}
]

Answer 1

没有现成的函数，您需要自己编写;但这应该很简单。这是一个很棒的减速器用例!

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce

const arr = [
{id: 408, customer_id: 2, bill_no: 381, bill_period: 'weekly', from_date: '2021-10-10'},
{id: 409, customer_id: 3, bill_no: 382, bill_period: 'weekly', from_date: '2021-10-10'},
{id: 410, customer_id: 4, bill_no: 383, bill_period: 'weekly', from_date: '2021-10-10'},
{id: 411, customer_id: 6, bill_no: 384, bill_period: 'weekly', from_date: '2021-10-10'},
{id: 412, customer_id: 7, bill_no: 385, bill_period: 'weekly', from_date: '2021-10-10'},
{id: 413, customer_id: 8, bill_no: 386, bill_period: 'weekly', from_date: '2021-10-10'},
{id: 414, customer_id: 9, bill_no: 387, bill_period: 'weekly', from_date: '2021-10-10'},
{id: 387, customer_id: 2, bill_no: 360, bill_period: 'weekly', from_date: '2021-10-03'},
{id: 388, customer_id: 3, bill_no: 361, bill_period: 'weekly', from_date: '2021-10-03'},
{id: 389, customer_id: 4, bill_no: 362, bill_period: 'weekly', from_date: '2021-10-03'},
{id: 390, customer_id: 6, bill_no: 363, bill_period: 'weekly', from_date: '2021-10-03'},
{id: 391, customer_id: 7, bill_no: 364, bill_period: 'weekly', from_date: '2021-10-03'},
{id: 392, customer_id: 8, bill_no: 365, bill_period: 'weekly', from_date: '2021-10-03'},
{id: 393, customer_id: 9, bill_no: 366, bill_period: 'weekly', from_date: '2021-10-03'},
{id: 380, customer_id: 2, bill_no: 353, bill_period: 'weekly', from_date: '2021-09-26'},
{id: 381, customer_id: 3, bill_no: 354, bill_period: 'weekly', from_date: '2021-09-26'},
{id: 382, customer_id: 4, bill_no: 355, bill_period: 'weekly', from_date: '2021-09-26'},
{id: 383, customer_id: 6, bill_no: 356, bill_period: 'weekly', from_date: '2021-09-26'},
{id: 384, customer_id: 7, bill_no: 357, bill_period: 'weekly', from_date: '2021-09-26'},
{id: 385, customer_id: 8, bill_no: 358, bill_period: 'weekly', from_date: '2021-09-26'},
{id: 386, customer_id: 9, bill_no: 359, bill_period: 'weekly', from_date: '2021-09-26'}
];
// reduce array to only relevant values to a single variable
const filtered = arr.reduce((accumulator, current) => {
// If customer data is already added to accumulator, don't add
if (accumulator.find(x => x.customer_id ===  current.customer_id)) {
return accumulator;
}
accumulator.push(current);
return accumulator;
}, []);
console.log(filtered);