Run results for: Array Intersection Comparison

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0

Browser: Firefox 78

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
intersect_for(shortArr1, shortArr2)	150416.4 Ops/sec
intersect_filter_indexOf(shortArr1, shortArr2)	152818.9 Ops/sec
intersect_filter_in(shortArr1, shortArr2)	708758.7 Ops/sec
intersect_for_in(shortArr1, shortArr2)	985539.3 Ops/sec
intersect_filter_includes(shortArr1, shortArr2)	124490.2 Ops/sec
intersect_filter_has_this(shortArr1, shortArr2)	131287.8 Ops/sec
intersect_filter_has_arrow(shortArr1, shortArr2)	128878.7 Ops/sec
intersect_for_has(shortArr1, shortArr2)	128608.3 Ops/sec

Script Preparation code:

var shortSize = 100;
var longSize = 10000;

var shortArr1 = Array.from({
    length: shortSize
}, () => Math.floor(Math.random() * shortSize));
var shortArr2 = Array.from({
    length: shortSize
}, () => Math.floor(Math.random() * shortSize));

function intersect_for(a, b) {
    const result = [];
    const alen = a.length;
    const blen = b.length;
    for (let i = 0; i < alen; ++i) {
        const ai = a[i];
        for (let j = 0; j < blen; ++j) {
            if (ai === b[j]) {
                result.push(ai);
                break;
            }
        }
    }
    return result;
}

function intersect_filter_indexOf(a, b) {
    return a.filter(el => b.indexOf(el) !== -1);
}

function intersect_filter_in(a, b) {
    const map = b.reduce((map, el) => {
        map[el] = true;
        return map
    }, {});
    return a.filter(el => el in map);
}

function intersect_for_in(a, b) {
    const result = [];
    const map = {};
    for (let i = 0, length = b.length; i < length; ++i) {
        map[b[i]] = true;
    }
    for (let i = 0, length = a.length; i < length; ++i) {
        if (a[i] in map) result.push(a[i]);
    }
    return result;
}

function intersect_filter_includes(a, b) {
    return a.filter(el => b.includes(el));
}

function intersect_filter_has_this(a, b) {
    return a.filter(Set.prototype.has, new Set(b));
}

function intersect_filter_has_arrow(a, b) {
    const set = new Set(b);
    return a.filter(el => set.has(el));
}

function intersect_for_has(a, b) {
    const result = [];
    const set = new Set(b);
    for (let i = 0, length = a.length; i < length; ++i) {
        if (set.has(a[i])) result.push(a[i]);
    }
    return result;
}

Tests:

intersect_for(shortArr1, shortArr2)
intersect_for(shortArr1, shortArr2)
intersect_filter_indexOf(shortArr1, shortArr2)
intersect_filter_indexOf(shortArr1, shortArr2)
intersect_filter_in(shortArr1, shortArr2)
intersect_filter_in(shortArr1, shortArr2)
intersect_for_in(shortArr1, shortArr2)
intersect_for_in(shortArr1, shortArr2)
intersect_filter_includes(shortArr1, shortArr2)
intersect_filter_includes(shortArr1, shortArr2)
intersect_filter_has_this(shortArr1, shortArr2)
intersect_filter_has_this(shortArr1, shortArr2)
intersect_filter_has_arrow(shortArr1, shortArr2)
intersect_filter_has_arrow(shortArr1, shortArr2)
intersect_for_has(shortArr1, shortArr2)
intersect_for_has(shortArr1, shortArr2)

Run results for: Array Intersection Comparison

intersect_for(shortArr1, shortArr2)

intersect_filter_indexOf(shortArr1, shortArr2)

intersect_filter_in(shortArr1, shortArr2)

intersect_for_in(shortArr1, shortArr2)

intersect_filter_includes(shortArr1, shortArr2)

intersect_filter_has_this(shortArr1, shortArr2)

intersect_filter_has_arrow(shortArr1, shortArr2)

intersect_for_has(shortArr1, shortArr2)