如何根据 javascript 中的时间戳对 3 个已排序的 arrays 进行排序

Question

Given 3 sorted arrays of objects, where each object has a timestamp key, how would I merge them into a single sorted array in Javascript, where the final array is sorted based on timestamp?

 // merge these messages, flights and hotels arrays into one array and sort them // messages, flights and hotels are already sorted const messages = [{"timestamp": "2019-06-28", "message": "messageVal"}, {"timestamp": "2019-06-29", "message": "messageVal"}]; const flights = [{"timestamp": "2019-08-19", "flight": "flightVal"}, {"timestamp": "2019-08-28", "flight": "flightVal"}]; const hotels = [{"timestamp": "2019-11-20", "hotel": "hotelVal"}];

Answer 1

You could combine these all in one array, flatten it and sort

 const messages = [ { timestamp: "2019-06-28", message: "messageVal" }, { timestamp: "2019-06-29", message: "messageVal" }, ] const flights = [ { timestamp: "2019-08-19", flight: "flightVal" }, { timestamp: "2019-08-28", flight: "flightVal" }, ] const hotels = [{ timestamp: "2019-11-20", hotel: "hotelVal" }] const res = [messages, flights, hotels].flat().sort((a, b) => b.timestamp - a.timestamp) console.log(res)

Answer 2

You can convert the timestamp property to Date, merge the arrays using flat() and then sort.

I did a simple function which can help you, it allows ascending and descending.

let array1 = [{"timestamp": "2019-06-30", "message": "1"}, {"timestamp": "2019-06-29", "message": "2"}];
let array2 = [{"timestamp": "2019-06-27", "message": "3"}, {"timestamp": "2019-06-26", "message": "4"}];

function sortArray(input, isDescending = false){
    return input.flat().sort((x1, x2) => isDescending ? new Date(x2.timestamp) - new Date(x1.timestamp) : new Date(x1.timestamp) - new Date(x2.timestamp));
}

console.log(sortArray([array1, array2])); //Ascending
console.log(sortArray([array1, array2], true)); //Descending