Benchmark: instanceof - MeasureThat.net

Script Preparation code:

var x = new Date();

Tests:

instanceof
x instanceof Date
other
Object.prototype.toString.call(x) === "[object Date]"

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
instanceof
other

Fastest: N/A

Slowest: N/A

Autogenerated LLM Sumamry (model llama3.2:3b, generated 4 days ago):

LLMs can make mistakes. Check important info.

I'd be happy to explain the provided benchmark and its various components.

**Benchmark Definition**

The benchmark definition is represented by the JSON object provided, which contains the following information:

* `Name`: The name of the benchmark, which in this case is "instanceof".
* `Description`: An empty string, indicating that there is no detailed description for this benchmark.
* `Script Preparation Code`: A JavaScript code snippet that sets up a variable `x` and assigns it a new Date object. This code prepares the environment for the test by creating an instance of the Date class.
* `Html Preparation Code`: An empty string, indicating that no HTML-related setup is required.

**Individual Test Cases**

The benchmark consists of two individual test cases:

1. `instanceof`:
	* The benchmark definition uses the `instanceof` operator to check if `x` (the Date object created in the script preparation code) is an instance of the Date class.
2. `other`:
	* This test case uses a different approach by calling `Object.prototype.toString.call(x)` and checking if the result matches the string representation of the Date class (`"[object Date]"`).

**Library and Purpose**

In this benchmark, the `Date` class is used as a built-in JavaScript object. There is no external library being tested.

**Special JS Feature or Syntax**

The `instanceof` operator is a special JavaScript operator that checks if an object is an instance of a particular constructor function. In this case, it's used to check if the `x` variable is an instance of the Date class.

**Pros and Cons of Different Approaches**

1. **Using `instanceof`**: This approach is simple and efficient, as it directly checks if `x` is an instance of the Date class.
	* Pros: Fast and straightforward.
	* Cons: May not work correctly for objects that have multiple constructors or prototype chains.
2. **Using `Object.prototype.toString.call(x)`**: This approach uses a more low-level method to check the type of object `x`.
	* Pros: Can handle objects with complex prototype chains or multiple constructors.
	* Cons: Slower and more verbose, as it requires calling a method on the Object prototype.

**Other Alternatives**

If you needed to test another JavaScript operator or function, MeasureThat.net provides various options for creating custom benchmarks. Some examples include:

* `===`, `!==`, `==`, `!=`
* Arithmetic operators (`+`, `-`, `*`, `/`)
* Comparison functions (e.g., `Math.min()`, `Array.prototype.indexOf()`)

Keep in mind that MeasureThat.net is specifically designed for testing JavaScript performance and microbenchmarks, so the options may be limited compared to a general-purpose benchmarking framework.

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/108.0.0.0 Safari/537.36 Edg/108.0.1462.46

Browser/OS: Chrome 108 on Windows

View result in a separate tab

Test name	Executions per second
instanceof	6558938.0 Ops/sec
other	6129833.0 Ops/sec

Related benchmarks:

instanceof (version: 0)

Comparing performance of: instanceof vs other

Created: one year ago by: Guest

Jump to the latest result

instanceof

other

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Sumamry (model llama3.2:3b, generated 4 days ago):