Benchmark: Testing isArray vs custom isArray vs pop vs array2

HTML Preparation code:

<script src="https://code.jquery.com/jquery-2.2.4.min.js"></script>

Script Preparation code:

var testArray = [1,2,3];
var fakeArray = 123;

var isArray = function(arr) {
    var type = Object.prototype.toString.call(arr);

    return (
        type === "[object Array]" ||
    type === "[object NodeList]" ||
    type === "[object TouchList]" ||
    type === "[object HTMLCollection]"
    );
};


var isArray2 = (arr) => arr.pop

Tests:

isArray
var a = 0; if (isArray(testArray)) { a++; }
Array.isArray
var a = 0; if (Array.isArray(testArray)) { a++; }
Optimized isArray1
var a = 0; if (testArray.length) { a++; }
Optimized isArray2
var a = 0; if (testArray && testArray.length) { a++; }
.pop
var a = 0; if (testArray.pop) { a++; }
isArray2
var a = 0; if (isArray2(testArray)) { a++; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
isArray
Array.isArray
Optimized isArray1
Optimized isArray2
.pop
isArray2

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark definitions and explain what's being tested, compared options, pros and cons of those approaches, library usage, special JS features or syntax, and other considerations.

**Benchmark Definition**

The benchmark is comparing the performance of different methods to determine if an array is actually an array:

1. `isArray` function
2. `Array.isArray()` method ( jQuery )
3. Checking `testArray.length`
4. Checking `testArray && testArray.length`
5. Calling `pop()` on `testArray`

**Options Compared**

* `isArray` function: checks if the input is an array using `Object.prototype.toString.call(arr)` and returns true if it matches certain types ( `[object Array]`, `[object NodeList]`, etc.)
* `Array.isArray()` method: uses jQuery's internal implementation to check if the input is an array
* Checking `testArray.length`: simply checks if the length property of the object is truthy, without checking its type
* Checking `testArray && testArray.length`: similar to the previous one, but also checks for nullability using the logical AND operator (`&&`)
* Calling `pop()` on `testArray`: calls the `pop()` method on the array and returns true if it's defined

**Pros and Cons of Each Approach**

1. `isArray` function:
	* Pros: provides more control over the check, can handle other types besides arrays
	* Cons: may have overhead due to the `Object.prototype.toString.call(arr)` call, not optimized for performance
2. `Array.isArray()` method:
	* Pros: optimized for performance by jQuery's internal implementation
	* Cons: relies on jQuery's internal workings, might not be compatible with non-JQuery environments
3. Checking `testArray.length`:
	* Pros: simple and lightweight, no overhead
	* Cons: may not work correctly for arrays that have a falsy length value (e.g., empty array)
4. Checking `testArray && testArray.length`:
	* Pros: similar to the previous one but also checks for nullability, reduces false positives
	* Cons: still might not work correctly for arrays with a falsy length value
5. Calling `pop()` on `testArray`:
	* Pros: simple and lightweight, no overhead
	* Cons: may not be accurate if the array is empty or has only one element

**Library Usage**

The benchmark uses jQuery's internal implementation of `Array.isArray()`. This is likely to optimize performance, but it also means that the result may not be compatible with non-JQuery environments.

**Special JS Features or Syntax**

None mentioned in this benchmark definition. However, it's worth noting that the `Object.prototype.toString.call(arr)` call used in the `isArray` function is a common pattern in JavaScript for determining object types, but it can be slow and inefficient for large datasets.

**Other Considerations**

* Memory usage: how much memory does each approach require?
* Cache behavior: do different approaches have different cache behaviors that affect performance?
* Browser compatibility: are all the tested browsers compatible with this benchmark?

As for alternatives, there are other methods to check if an object is an array, such as using a regular expression (`/^\[.*\]$/.test(arr)`), or implementing a custom implementation like in the `isArray` function. However, these approaches may have different performance characteristics and should be tested separately.

To further improve this benchmark, you could consider adding more test cases to cover edge cases (e.g., empty arrays, arrays with falsy length values), measuring memory usage for each approach, or using a more accurate timing measurement method (e.g., `performance.now()`).

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36

Browser/OS: Chrome 69 on Mac OS X 10.14.0

View result in a separate tab

Test name	Executions per second
isArray	2929452.0 Ops/sec
Array.isArray	4068260.0 Ops/sec
Optimized isArray1	13626520.0 Ops/sec
Optimized isArray2	6786108.5 Ops/sec
.pop	13583411.0 Ops/sec
isArray2	6844288.0 Ops/sec

Related benchmarks:

Testing isArray vs custom isArray vs pop vs array2 (version: 5)

Testing isArray vs jQuery.type === "array"

Comparing performance of: isArray vs Array.isArray vs Optimized isArray1 vs Optimized isArray2 vs .pop vs isArray2

Created: 6 years ago by: Registered User

Jump to the latest result

isArray

Array.isArray

Optimized isArray1

Optimized isArray2

.pop

isArray2

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):