Benchmark: Group By Comparison; For, For Of, and Reduce

Script Preparation code:

var count = 100000;
var groupBy = "group";
var rows = Array.from({
    length: count
});

for (let i = 0; i < count; i++) {
    rows[i] = {
        id: i,
        group: `group-${Math.ceil(Math.random() * 4)}`,
        value: Math.random() * 100000,
    };
}

function groupByFor(field, data) {
    var result = {};

    for (let i = 0; i < data.length; i++) {
        var item = data[i];
        var key = `${item[field]}`;

        if (!result[key]) {
            result[key] = [];
        }

        result[key].push(item);
    }

    return result;
};

function groupByForOf(field, data) {
    var result = {};

    for (var [index, item] of data.entries()) {
        var item = data[index];
        var key = `${item[field]}`;

        if (!result[key]) {
            result[key] = [];
        }

        result[key].push(item);
    }

    return result;
};

function groupByReduce(field, data) {
    return data.reduce((result, item) => {
        var key = `${item[field]}`;

        if (!result[key]) {
            result[key] = [];
        }

        result[key].push(item);
        return result;
    }, {});
};

Tests:

For Loop
var result = groupByFor(groupBy, rows);
For Of
var result = groupByForOf(groupBy, rows);
Reduce
var result = groupByReduce(groupBy, rows);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
For Loop
For Of
Reduce

Fastest: N/A

Slowest: N/A

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Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.36

Browser/OS: Chrome 110 on Windows

View result in a separate tab

Test name	Executions per second
For Loop	389.8 Ops/sec
For Of	324.1 Ops/sec
Reduce	323.3 Ops/sec

Group By Comparison; For, For Of, and Reduce (version: 0)

Comparing performance of: For Loop vs For Of vs Reduce

Created: one year ago by: Guest

Jump to the latest result

For Loop

For Of

Reduce

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A