Benchmark: constructor comparison vs. instanceof vs Array.isArray 2

Script Preparation code:

array = []
ctor = array.conatructor

Tests:

constructor comparison
ctor === Array
instanceof operator
array instanceof Array
Array.isArray call
Array.isArray(array)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
constructor comparison
instanceof operator
Array.isArray call

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 YaBrowser/24.7.0.0 Safari/537.36

Browser/OS: Yandex Browser 24 on Linux

View result in a separate tab

Test name	Executions per second
constructor comparison	10247796.0 Ops/sec
instanceof operator	10299846.0 Ops/sec
Array.isArray call	11119899.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**Benchmark Definition JSON**

The provided JSON represents a benchmark definition for measuring the performance of comparing a constructor strictly to a function object using three different approaches:

1. `ctor === Array`
2. `array instanceof Array`
3. `Array.isArray(array)`

These three approaches are used to compare the performance of each method.

**Approach 1: Constructor Comparison (`ctor === Array`)**

In this approach, a constructor is created for an array using the syntax `array.constructor = array.constructor`. This creates a reference between the original array and its constructor. The comparison then checks if the constructed object is equal to the array using `ctor === Array`.

Pros:

* Simple and straightforward implementation
* Does not require any additional libraries

Cons:

* May involve creating an unnecessary reference to the array's constructor, which could lead to performance overhead.

**Approach 2: instanceof Operator (`array instanceof Array`)**

The `instanceof` operator checks if an object is an instance of a specified constructor. In this case, it checks if the constructed object is an instance of the `Array` constructor.

Pros:

* Wide support across browsers and platforms
* Does not require any additional libraries or manual reference management

Cons:

* May involve creating an unnecessary object on the heap to store the reference, which could lead to performance overhead.

**Approach 3: Array.isArray Call (`Array.isArray(array)`)**

The `Array.isArray` method checks if a given value is an array. In this case, it checks if the constructed object is an array using `Array.isArray(array)`.

Pros:

* Wide support across browsers and platforms
* Does not require any additional libraries or manual reference management

Cons:

* May involve creating an unnecessary object on the heap to store the reference, which could lead to performance overhead.

**Library Usage**

None of the test cases use a specific JavaScript library. However, it's worth noting that some browsers may provide additional functions or methods for working with arrays, such as `Array.prototype.slice()` or `Array.prototype.forEach()`, which are not used in this benchmark.

**Special JS Features/Syntax**

There are no special JS features or syntax used in this benchmark. The code is written in plain JavaScript and does not utilize any advanced language features like ES6 modules, async/await, or generators.

**Other Alternatives**

Some alternative approaches to comparing constructors and arrays could include:

* Using a custom function to compare the two
* Creating a wrapper function around `Array.isArray`
* Utilizing browser-specific APIs for array validation (e.g., Chrome's `Array.prototype.validate()` method)

However, these alternatives are not included in the benchmark definition provided.

Overall, the benchmark measures the performance of three different approaches to comparing constructors and arrays. The choice of approach may impact performance, so it's essential to understand the trade-offs involved in each method.

Related benchmarks:

constructor comparison vs. instanceof vs Array.isArray 2 (version: 0)

Compares the performance of comparing a constructor strictly to a function object, using the instanceof operator and calling Array.isArray

Comparing performance of: constructor comparison vs instanceof operator vs Array.isArray call

Created: 5 years ago by: Registered User

Jump to the latest result

constructor comparison

instanceof operator

Array.isArray call

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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