Benchmark: instanceof vs regular comparison

Script Preparation code:

var dateList = [];
var currentDateTime = Date.now();
for (i = 0; i < 10000; i++) {
    var randomInt = Math.round(Math.random()); // This will randomly returns either 0 or 1.
    if (randomInt === 0) {
        dateList.push(null); // Fill the array with a null value.
    } else {
        dateList.push(addMinutes(currentDateTime, i)); // This will fill up the array with date objects.
    }
}

function addMinutes(dt, minutes) {
    return new Date(dt + minutes * 60000);
}

Tests:

Check with regular comparison
var counter = 0; for (i = 0; i < 10000; i++) { if (!!dateList[i]) { counter++; } }
Check using instanceof comparison
var counter = 0; for (i = 0; i < 10000; i++) { if (dateList[i] instanceof Date) { counter++; } }
Check using regular and instanceof comparison
var counter = 0; for (i = 0; i < 10000; i++) { if (!!dateList[i] && dateList[i] instanceof Date) { counter++; } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Check with regular comparison
Check using instanceof comparison
Check using regular and instanceof comparison

Fastest: N/A

Slowest: N/A

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Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:87.0) Gecko/20100101 Firefox/87.0

Browser/OS: Firefox 87 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
Check with regular comparison	3045.7 Ops/sec
Check using instanceof comparison	2592.9 Ops/sec
Check using regular and instanceof comparison	2309.5 Ops/sec

instanceof vs regular comparison (version: 2)

We try to check if comparing value using regular existence comparison is more efficient than comparing using instanceof.

Comparing performance of: Check with regular comparison vs Check using instanceof comparison vs Check using regular and instanceof comparison

Created: 3 years ago by: Registered User

Jump to the latest result

Check with regular comparison

Check using instanceof comparison

Check using regular and instanceof comparison

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A