我有这个带有对象的数组:
var data=[
{ number: '31907411282', unix_date: '1547012427' },
{ number: '31907411282', unix_date: '1547013214' },
{ number: '31907514691', unix_date: '1547015155' },
{ number: '31907514691', unix_date: '1547015232' },
{ number: '31907514691', unix_date: '1547016134' },
{ number: '31907514691', unix_date: '1547016443' },
{ number: '31907638716', unix_date: '1547017122' },
{ number: '31907644067', unix_date: '1547017381' }
]
如何删除具有较新日期的重复对象并获取如下所示的新数组:
var new_data=[
{ number: '31907411282', unix_date: '1547012427' },
{ number: '31907514691', unix_date: '1547015155' },
{ number: '31907638716', unix_date: '1547017122' },
{ number: '31907644067', unix_date: '1547017381' }
]
我无法理解如何做所有程序。谢谢
UPDATE
我尝试这种结构:
码:
var data=[
{ number: '31907411282', unix_date: '1547012427' },
{ number: '31907411282', unix_date: '1547013214' },
{ number: '31907514691', unix_date: '1547019134' },
{ number: '31907514691', unix_date: '1547015232' },
{ number: '31907514691', unix_date: '1547016134' },
{ number: '31907514691', unix_date: '1547016443' },
{ number: '31907638716', unix_date: '1547017122' },
{ number: '31907644067', unix_date: '1547017381' }
]
var new_data=[];
var groupByNumber=groupBy(data, 'number');
for(i in groupByNumber){
var sort_arr=groupByNumber[i].sort(compare)
new_data.push(sort_arr[0])
}
console.log(new_data)
function compare(a, b) {
let comparison = 0;
if (a.unix_date > b.unix_date) {
comparison = 1;
} else if (a.unix_date < b.unix_date) {
comparison = -1;
}
return comparison;
}
function groupBy(xs, key) { //group by key
return xs.reduce(function(rv, x) {
(rv[x[key]] = rv[x[key]] || []).push(x);
return rv;
}, {});
};
也许它可以更优雅
更新2
@ miroslav-glamuzina提供更优雅的方式:
let filtered = data.reduce((acc, item) => {
if (!acc.some((e, i) => {
if (item.number === e.number) {
if (item.unix_date < e.unix_date) {
acc.splice(i, 1, item);
}
return true;
}
})) {
acc.push(item);
}
return acc;
}, []);
您可以使用reduce来实现此目的:
var data = [{
number: '31907411282',
unix_date: '1547013214'
},
{
number: '31907411282',
unix_date: '1547012427'
},
{
number: '31907514691',
unix_date: '1547015155'
},
{
number: '31907514691',
unix_date: '1547015232'
},
{
number: '31907514691',
unix_date: '1547016134'
},
{
number: '31907514691',
unix_date: '1547016443'
},
{
number: '31907638716',
unix_date: '1547017122'
},
{
number: '31907644067',
unix_date: '1547017381'
}
];
let filtered = data.reduce((acc, item) => {
if (!acc.some((e, i) => {
if (item.number === e.number) {
if (item.unix_date < e.unix_date) {
acc.splice(i, 1, item);
}
return true;
}
})) {
acc.push(item);
}
return acc;
}, []);
console.log(filtered);
希望这可以帮助,
您可以使用reduce
循环遍历数组并存储一组键(number
)以检查是否存在。然后推入新阵列。
var data=[
{ number: '31907411282', unix_date: '1547012427' },
{ number: '31907411282', unix_date: '1547013214' },
{ number: '31907514691', unix_date: '1547015155' },
{ number: '31907514691', unix_date: '1547015232' },
{ number: '31907514691', unix_date: '1547016134' },
{ number: '31907514691', unix_date: '1547016443' },
{ number: '31907638716', unix_date: '1547017122' },
{ number: '31907644067', unix_date: '1547017381' }
]
const rs = data.reduce((acc, e) => {
if(!acc.number.has(e.number)) {
acc.newData.push(e)
acc.number.add(e.number)
}
return acc
}, {number: new Set(), newData: []})
console.log(rs.newData)
按日期对项目进行排序,减少数组,仅保留具有累加器数组中尚不存在的number
的元素。
let data = [{
number: '31907411282',
unix_date: '1547013214'
},
{
number: '31907411282',
unix_date: '1547012427'
},
{
number: '31907514691',
unix_date: '1547015155'
},
{
number: '31907514691',
unix_date: '1547015232'
},
{
number: '31907514691',
unix_date: '1547016134'
},
{
number: '31907514691',
unix_date: '1547016443'
},
{
number: '31907638716',
unix_date: '1547017122'
},
{
number: '31907644067',
unix_date: '1547017381'
}
];
let filtered = data
.sort((a, b) => (a.unix_date > b.unix_date) ? 1 : -1)
.reduce((acc, item) => {
if (!acc.find(el => el.number === item.number)) {
acc.push(item)
}
return acc
}, []);
console.log(filtered);