Sorting of an array of objects by multiple fields in JavaScript varies based on object position in t-CodePudding

While researching on the mechanism for sorting arrays in JavaScript by multiple properties/fields/attributes, I've come across this article. For my personal project I have utilized the solution offered by @chriskelly.

function comparator(attrs) {
    return function (v1, v2) {
        return attrs
            .map(function (fld) {
                var ad = 1;
                if (fld[0] === '-') {
                   ad = -1;
                   fld = fld.substring(1);
                }
                if (v1[fld] > v2[fld]) return ad;
                if (v1[fld] < v2[fld]) return -(ad);
                return 0;
            })
            .reduce(function nonZero (v3, v4) {
                return v3 ? v3 : v4;
            }, 0);
    };
}

My input array is the following:

[{"name":"Pass9884881","fld1d":10,"fld2d":25,"fld4d":383,"fld3d":626490,"fld5a":0,"date":"09/27/2021","time":"18:23:31"},
 {"name":"Driver1","fld1d":"10","fld2d":25,"fld4d":356,"fld3d":559650,"fld5a":0,"date":"10/18/2021","time":"14:48:17"},
 {"name":"Driver321","fld1d":10,"fld2d":22,"fld4d":346,"fld3d":554400,"fld5a":1,"date":"08/08/2021","time":"22:35:03"},
 {"name":"Driverxyz","fld1d":9,"fld2d":25,"fld4d":350,"fld3d":497190,"fld5a":0,"date":"07/26/2021","time":"14:23:33"},
 {"name":"Pass1974761","fld1d":"9","fld2d":25,"fld4d":316,"fld3d":477290,"fld5a":0,"date":"10/11/2021","time":"19:20:33"},
 {"name":"Pass7374147","fld1d":"9","fld2d":23,"fld4d":279,"fld3d":376750,"fld5a":0,"date":"10/10/2021","time":"20:13:15"},
 {"name":"Driver0","fld1d":8,"fld2d":25,"fld4d":286,"fld3d":435940,"fld5a":0,"date":"07/26/2021","time":"12:31:42"},
 {"name":"Pass1536735","fld1d":"8","fld2d":25,"fld4d":236,"fld3d":329880,"fld5a":0,"date":"10/09/2021","time":"17:19:14"},
 {"name":"#xxxxyyyy","fld1d":"10","fld2d":25,"fld4d":329,"fld3d":500440,"fld5a":0,"date":"11/04/2021","time":"00:04:17"},
 {"name":"Pass7668209","fld1d":"8","fld2d":24,"fld4d":203,"fld3d":267150,"fld5a":0,"date":"10/09/2021","time":"00:22:18"}]

It meant to be sorted by fld1d (desc), fld2d (desc), fld3d (desc), fld4d (desc), fld5a (asc), date (asc) and time (asc). When the object with "name":"#xxxxyyyy" is placed the last or next to the last in the input data (gets read in from an external file in the code), the resulting sorted array appears incorrect: Incorrectly sorted array

However, if I move that object in the input file to the 8th position (out of 10) or above, the resulting sorted array is correct: Correctly sorted array

I ought to admit, I am not a professional developer - just an interested party who somewhat learnt to follow examples, and I'm having hard time explaining the discrepancy in the results.

Suggestions would be greatly appreciated.

CodePudding user response：

You could take a simplified approach and chain all sorting crieria by taking the delta or use a string comparison.

const
    getISO = (date, time) => `${date.slice(3, 5)}-${date.slice(0, 2)}-${date.slice(6, 10)}T${time}`;
    data = [{ name: "Pass9884881", fld1d: 10, fld2d: 25, fld4d: 383, fld3d: 626490, fld5a: 0, date: "09/27/2021", time: "18:23:31" }, { name: "Driver1", fld1d: "10", fld2d: 25, fld4d: 356, fld3d: 559650, fld5a: 0, date: "10/18/2021", time: "14:48:17" }, { name: "Driver321", fld1d: 10, fld2d: 22, fld4d: 346, fld3d: 554400, fld5a: 1, date: "08/08/2021", time: "22:35:03" }, { name: "Driverxyz", fld1d: 9, fld2d: 25, fld4d: 350, fld3d: 497190, fld5a: 0, date: "07/26/2021", time: "14:23:33" }, { name: "Pass1974761", fld1d: "9", fld2d: 25, fld4d: 316, fld3d: 477290, fld5a: 0, date: "10/11/2021", time: "19:20:33" }, { name: "Pass7374147", fld1d: "9", fld2d: 23, fld4d: 279, fld3d: 376750, fld5a: 0, date: "10/10/2021", time: "20:13:15" }, { name: "Driver0", fld1d: 8, fld2d: 25, fld4d: 286, fld3d: 435940, fld5a: 0, date: "07/26/2021", time: "12:31:42" }, { name: "Pass1536735", fld1d: "8", fld2d: 25, fld4d: 236, fld3d: 329880, fld5a: 0, date: "10/09/2021", time: "17:19:14" }, { name: "#xxxxyyyy", fld1d: "10", fld2d: 25, fld4d: 329, fld3d: 500440, fld5a: 0, date: "11/04/2021", time: "00:04:17" }, { name: "Pass7668209", fld1d: "8", fld2d: 24, fld4d: 203, fld3d: 267150, fld5a: 0, date: "10/09/2021", time: "00:22:18" }],

data.sort((a, b) =>
    b.fld1d - a.fld1d ||
    b.fld2d - a.fld2d ||
    b.fld3d - a.fld3d ||
    b.fld4d - a.fld4d ||
    a.fld5a - b.fld5a ||
    getISO(a.date, a.time).localeCompare(getISO(b.date, b.time))
);

console.log(data);

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