Run results for: InstanceOf vs String type vs Symbol

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.3 Safari/605.1.15

Browser: Safari 15

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
instanceof	5026851.0 Ops/sec
string type	12037120.0 Ops/sec
string type + undefined	3695302.0 Ops/sec
property	3754270.0 Ops/sec
symbol	3929437.0 Ops/sec

HTML Preparation code:

<script>
var S = Symbol('symbol')
class TestClass {
    constructor() {
        this.a = 2;
        this.t = 'mesh';
  		this.s = S
    }
}
</script>

Script Preparation code:

var obj = new TestClass();

Tests:

instanceof
obj instanceof TestClass;
string type
obj.t === 'mesh'
string type + undefined
obj.t !== undefined
property
obj.a !== undefined
symbol
obj.s === S

Run results for: InstanceOf vs String type vs Symbol

Measure the performance of instanceOf operator vs comparing a basic string type and vs Symbol comparison.

instanceof

string type

string type + undefined

property

symbol