Benchmark: instanceof vs typeof gyuguyguy

Script Preparation code:

var obj = () => {};

Tests:

instanceof
obj instanceof Object
typeof
typeof obj === "function"

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
instanceof
typeof

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.4 Safari/605.1.15

Browser/OS: Safari 17 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
instanceof	12349535.0 Ops/sec
typeof	32610850.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

I'd be happy to help you understand what's being tested in this JavaScript microbenchmark.

**What is being tested?**

The benchmark is comparing the performance of two different ways to check if an object is a function using:

1. `obj instanceof Object` (instanceof)
2. `typeof obj === "function"` (typeof)

**Options compared:**

* Using the `instanceof` operator
* Using the `typeof` operator with a string comparison

**Pros and cons of each approach:**

* **Using `instanceof` operator:**
	+ Pros:
		- More explicit and readable way to check if an object is a function.
		- Can be faster in some cases, since it doesn't require a string comparison.
	+ Cons:
		- May not work as expected with certain types of objects or inheritance hierarchies.
* **Using `typeof` operator with string comparison:**
	+ Pros:
		- More concise and expressive way to check if an object is a function.
		- Works well with most types of objects and inheritance hierarchies.
	+ Cons:
		- Requires an explicit string comparison, which can be slower than the `instanceof` operator.

**Library and special JavaScript features used:**

* No libraries are explicitly mentioned in the benchmark definition or test cases. However, it's likely that the benchmark is running on a modern JavaScript engine that supports the `typeof` operator.
* Special JavaScript feature:
	+ The use of arrow functions (`() => {}`) is mentioned in the script preparation code. This feature was introduced in ECMAScript 2015 (ES6) and allows for concise, anonymous function expressions.

**Other considerations:**

* The benchmark uses a desktop Safari 17 browser on a Mac OS X 10.15.7 device platform.
* The test cases are executed at a rate of approximately 32 million executions per second.

**Alternatives to JavaScript microbenchmarks like MeasureThat.net:**

* Other online platforms that offer similar benchmarking capabilities, such as:
	+ JSBench
	+ Benchmark.js
	+ Microbenchmark
* Browser-specific benchmarks or testing tools, such as Chrome DevTools' performance profiling tools.
* Library-specific benchmarks or testing tools, such as Jest's benchmarking features.

Related benchmarks:

instanceof vs typeof gyuguyguy (version: 0)

Comparing performance of: instanceof vs typeof

Created: 2 years ago by: Guest

Jump to the latest result

instanceof

typeof

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):