Run results for: Javascript array deducplication.

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/106.0.0.0 Safari/537.36

Browser: Chrome 106

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
m	4006756.2 Ops/sec
n	1290335.4 Ops/sec
unique	1691199.9 Ops/sec

Script Preparation code:

function m(l1, l2) {
    var u = [];
    for (var i = 0; i < l1.length; i++) {
        u.push(l1[i]);
    }
    for (var j = 0; j < l2.length; j++) {
        var dupe = false;
        for (var i = 0; i < l1.length; i++) {
            if (l1[i] === l2[j]) {
                dupe = true;
            }
        }
        if (!dupe) {
            u.push(l2[j]);
        }
    }
    return u;
}

function n(l1, l2) {
    let combined = [].concat(l1, l2);
    return [...new Set(combined)];
}

Array.prototype.unique = function() {
    var a = this.concat();
    for(var i=0; i<a.length; ++i) {
        for(var j=i+1; j<a.length; ++j) {
            if(a[i] === a[j])
                a.splice(j--, 1);
        }
    }

    return a;
};

var a = [1, 2, 3, 4, 5];
var b = [3, 3, 4, 5, 5, 6, 7];

Tests:

m
var testM = m(a, b);
n
var testN = n(a, b);
unique
var testUnique = a.concat(b).unique();

Run results for: Javascript array deducplication.

yes.

m

n

unique