Benchmark: Test Set versus Array-like object perfomance

Script Preparation code:

var iSet = new Set();
var arr = [];
arr.byNum = {};

Tests:

Array Obj add
for (var i = 0;i++;i<50) { for (var j = 1;j++;j<10) { if (!arr.byNum[i]) { arr.push(i); arr.byNum[i] = i; } } }
Set add
for (var i = 0;i++;i<50) { for (var j = 1;j++;j<10) { iSet.add(i); } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array Obj add
Set add

Fastest: N/A

Slowest: N/A

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

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Let's break down the provided benchmark and explain what is being tested, compared, and the pros and cons of each approach.

**Benchmark Overview**

The benchmark compares the performance of adding elements to an array-like object (specifically, `arr.byNum`) versus using a built-in JavaScript data structure called a Set (`iSet`). The test cases focus on iterating over a range of numbers and pushing/pushing elements into the array-like object and set, respectively.

**Script Preparation Code**

The provided script preparation code initializes two variables:

* `iSet`: a new instance of the Set data structure.
* `arr`: an empty array with a custom property `byNum`.

The `byNum` property is assigned an object that will store numbers as keys. This is not a standard array-like behavior, but it's used in this benchmark to create a custom array-like object.

**Test Cases**

There are two test cases:

1. **"Array Obj add"`: This test case iterates over a range of numbers and pushes elements into the `arr.byNum` object using the `push()` method.
2. **"Set add"`: This test case iterates over the same range of numbers and adds elements to the `iSet` data structure using the `add()` method.

**Comparison**

The benchmark compares the performance of adding elements to an array-like object (`arr.byNum`) versus a built-in JavaScript Set data structure (`iSet`). The results are reported in terms of executions per second (ExecutionsPerSecond).

**Pros and Cons**

* **Array-like Object (`arr.byNum`)**:
	+ Pros: This approach is more familiar to developers who work with arrays, as it uses the `push()` method and creates a custom array-like object.
	+ Cons: This approach can lead to performance issues due to the overhead of creating and managing an array-like object. Additionally, this approach does not leverage the optimized algorithms used by JavaScript's built-in Set data structure.
* **Set Data Structure (`iSet`)**:
	+ Pros: Sets are designed for efficient insertion and lookup operations, making them well-suited for this benchmark. This approach can provide better performance compared to an array-like object.
	+ Cons: This approach requires developers to be familiar with the Set data structure and its methods (e.g., `add()`).

**Library/Feature Consideration**

In this benchmark, there is no explicit use of a library or special JavaScript feature besides using the built-in Set data structure. However, if you were to modify the script preparation code to include external libraries or features like Web Workers, it would affect the performance results.

**Other Alternatives**

If you want to explore alternative approaches for adding elements to an array-like object, consider the following:

1. **Using `unshift()` instead of `push()`:`** This can be a more efficient approach, but it's not supported in older browsers.
2. **Using a custom array implementation:** You could create your own array-like data structure using JavaScript objects or other data structures.
3. **Using a library like Lodash:** If you need to perform complex array operations, consider using a utility library like Lodash.

Keep in mind that the choice of approach depends on your specific use case and performance requirements.

**Benchmark Interpretation**

Based on the provided results, we can see that adding elements to an `iSet` data structure is faster than adding elements to an array-like object (`arr.byNum`). This suggests that using built-in JavaScript data structures like Sets can lead to better performance in certain scenarios.

Related benchmarks:

Test Set versus Array-like object perfomance (version: 0)

Comparing performance of: Array Obj add vs Set add

Created: 7 years ago by: Guest

Jump to the latest result

Array Obj add

Set add

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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