Benchmark: instanceof vs manual checking

Script Preparation code:

class Base {
   constructor() {
     this.a = 123; 
   }
  
   doSomething() {
     console.log(this.a); 
   }
}

class Extender extends Base {
 	constructor() {
      super();
      this.b = 345;
    }
}

const objBase = new Base();
const objExt = new Extender();

Tests:

base instanceof Base
objBase instanceof Base
extender instanceof Base
objExt instanceof Base
base instanceof Extender
objBase instanceof Extender
extender instanceof Extender
objExt instanceof Extender
objBase check property
!!objBase.b
objExtender check property
!!objExt.b

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
base instanceof Base
extender instanceof Base
base instanceof Extender
extender instanceof Extender
objBase check property
objExtender check property

Fastest: N/A

Slowest: N/A

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/133.0.0.0 Safari/537.36

Browser/OS: Chrome 133 on Windows

View result in a separate tab

Test name	Executions per second
base instanceof Base	113808528.0 Ops/sec
extender instanceof Base	115179872.0 Ops/sec
base instanceof Extender	118679016.0 Ops/sec
extender instanceof Extender	127838376.0 Ops/sec
objBase check property	123774040.0 Ops/sec
objExtender check property	113899272.0 Ops/sec

Related benchmarks:

instanceof vs manual checking (version: 1)

Determining if instanceof is slower than checking against a known property

Comparing performance of: base instanceof Base vs extender instanceof Base vs base instanceof Extender vs extender instanceof Extender vs objBase check property vs objExtender check property

Created: one year ago by: Guest

Jump to the latest result

base instanceof Base

extender instanceof Base

base instanceof Extender

extender instanceof Extender

objBase check property

objExtender check property

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A