比较2个数组并在Javascript中进行组合

Question

如何使用javascript或lodash的数组函数比较和组合2个数组？

我有最后30天的初始日期数组。

[
'2022-12-11', '2022-12-12', '2022-12-13',
'2022-12-14', '2022-12-15', '2022-12-16',
'2022-12-17', '2022-12-18', '2022-12-19',
'2022-12-20', '2022-12-21', '2022-12-22',
'2022-12-23', '2022-12-24', '2022-12-25',
'2022-12-26', '2022-12-27', '2022-12-28',
'2022-12-29', '2022-12-30', '2022-12-31',
'2023-01-01', '2023-01-02', '2023-01-03',
'2023-01-04', '2023-01-05', '2023-01-06',
'2023-01-07', '2023-01-08', '2023-01-09',
'2023-01-10', '2023-01-11'
]

这是第二个有计数值的。

[ [ '2023-01-09', 1 ], [ '2023-01-10', 3 ] ]

现在我有了这个代码，可以手动比较和组合这些阵列

let testData = [];
let k = 0;
dayList.forEach(o => {
let is_match = 0;
let frags = [];
submitted.forEach(i => {
if(o == i[0]){
is_match = 1;
frags = i;
}
});
testData[k] = [
(is_match == 1) ? frags[0] : o,
(is_match == 1) ? frags[1] : 0
];
k++;
});
console.log(testData);

这将导致…

[
[ '2022-12-11', 0 ], [ '2022-12-12', 0 ],
[ '2022-12-13', 0 ], [ '2022-12-14', 0 ],
[ '2022-12-15', 0 ], [ '2022-12-16', 0 ],
[ '2022-12-17', 0 ], [ '2022-12-18', 0 ],
[ '2022-12-19', 0 ], [ '2022-12-20', 0 ],
[ '2022-12-21', 0 ], [ '2022-12-22', 0 ],
[ '2022-12-23', 0 ], [ '2022-12-24', 0 ],
[ '2022-12-25', 0 ], [ '2022-12-26', 0 ],
[ '2022-12-27', 0 ], [ '2022-12-28', 0 ],
[ '2022-12-29', 0 ], [ '2022-12-30', 0 ],
[ '2022-12-31', 0 ], [ '2023-01-01', 0 ],
[ '2023-01-02', 0 ], [ '2023-01-03', 0 ],
[ '2023-01-04', 0 ], [ '2023-01-05', 0 ],
[ '2023-01-06', 0 ], [ '2023-01-07', 0 ],
[ '2023-01-08', 0 ], [ '2023-01-09', 1 ],
[ '2023-01-10', 3 ], [ '2023-01-11', 0 ]
]

正如您所看到的，日期2023-01-09和22023-01-10有值，其余的值为0。

这正是我所期望的，我刚开始编写纯javascript应用程序，我刚刚将PHP代码翻译成javascript。

现在有没有一种方法可以使用javascript的数组函数或lodash来简化这些代码？

Answer 1

这里有一种方法，我们首先创建一个以日期为键、计数为值的映射，然后使用该映射生成结果

const dates=["2022-12-11","2022-12-12","2022-12-13","2022-12-14","2022-12-15","2022-12-16","2022-12-17","2022-12-18","2022-12-19","2022-12-20","2022-12-21","2022-12-22","2022-12-23","2022-12-24","2022-12-25","2022-12-26","2022-12-27","2022-12-28","2022-12-29","2022-12-30","2022-12-31","2023-01-01","2023-01-02","2023-01-03","2023-01-04","2023-01-05","2023-01-06","2023-01-07","2023-01-08","2023-01-09","2023-01-10","2023-01-11",];
const count=[["2023-01-09",1],["2023-01-10",3]];
const countMap = count.reduce((acc, [date, count]) => {
acc[date] = count;
return acc;
}, {});
const result = dates.map((date) => [date, countMap[date] || 0]);
console.log(result)

Answer 2

您可以简单地运行任何循环，在提交的数组中找到当前元素的索引，并检查是否存在，然后分配日期，否则将0分配给数组

var dayList = ['2022-12-11', '2023-01-10', '2023-01-09']
var submitted = [ [ '2023-01-09', 1 ], [ '2023-01-10', 3 ] ]
var testData = []
dayList.filter(o => {
const exist = submitted.find(e => e.indexOf(o) != -1)
if(exist){
testData.push([o, exist[1]])
} else {
testData.push([o, 0])
}
});
console.log("your data=", testData)