Unsure how to sort 2d javascript array by date-CodePudding

Referencing How to sort an object array by date property?, why doesn't this work?

let arr = [];
arr.push(["07-Mar-2022", "BG76694", "PETE FRAMPTON"]);
arr.push(["07-Mar-2022", "AQ80789", "BARACK OBAMA"]);
arr.push(["08-Mar-2022", "BE39395", "CHEVY CHASE"]);
arr.push(["01-Feb-2022", "AU78617", "GEORGE LUCAS"]);
arr.push(["28-Feb-2022", "BF62132", "GEORGE WASHINGTON"]);
arr.sort((a,b) => new Date(a[0].date) - new Date(b[0].date));
console.log(arr[0][0]);

It doesn't matter what dates I enter, the output is the date from the first element of the unsorted array (in this case "07-Mar-2022"). My understanding is that sort sorts the array in place, ie. it changes the original array. I would expect the output in the above to be "01-Feb-2022" (or else "08-Mar-2022" if I have the sort direction confused.)

CodePudding user response：

There's no date in the array elements as they are arrays. You can sort by the first item of each array as follows:

const arr = [];
arr.push(["07-Mar-2022", "BG76694", "PETE FRAMPTON"]);
arr.push(["07-Mar-2022", "AQ80789", "BARACK OBAMA"]);
arr.push(["08-Mar-2022", "BE39395", "CHEVY CHASE"]);
arr.push(["01-Feb-2022", "AU78617", "GEORGE LUCAS"]);
arr.push(["28-Feb-2022", "BF62132", "GEORGE WASHINGTON"]);

arr.sort((a, b) => new Date(a[0]) - new Date(b[0]));

console.log(arr);

Shorthand:

arr.sort(([a], [b]) => new Date(a) - new Date(b));

CodePudding user response：

let arr = [];
arr.push(["07-Mar-2022", "BG76694", "PETE FRAMPTON"]);
arr.push(["07-Mar-2022", "AQ80789", "BARACK OBAMA"]);
arr.push(["08-Mar-2022", "BE39395", "CHEVY CHASE"]);
arr.push(["01-Feb-2022", "AU78617", "GEORGE LUCAS"]);
arr.push(["28-Feb-2022", "BF62132", "GEORGE WASHINGTON"]);
arr.sort((a,b) => new Date(a[0]).getTime() - new Date(b[0]).getTime());
console.log(arr);

use getTime() to get the time in milliseconds also you are accessing a property 'date' that doesn't exist