Benchmark: set prop on object vs array.push: no extra obj creation

Tests:

set prop on object
let o = {} let id = 0 o[++id] = o o[++id] = o o[++id] = o o[++id] = o o[++id] = o
array.push
let a = [] a.push(a) a.push(a) a.push(a) a.push(a) a.push(a)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
set prop on object
array.push

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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I'll break down the provided benchmark definition and explain what's being tested, compared, and their pros and cons.

**Benchmark Definition**

The benchmark measures the performance difference between two approaches:

1. **Set property on an object**: The script `o[++id] = o` creates a new property on an object `o` with a key that increments every time.
2. **Array.push**: The script `a.push(a)` adds an element to an array `a`, where the element is another instance of the same array.

**What's being tested**

The benchmark aims to compare how efficiently these two approaches allocate memory and execute the operations on objects and arrays in modern JavaScript engines (in this case, Chrome 119).

**Approaches compared**

There are two main differences between the two approaches:

* **Memory allocation**: In the object approach, a new property is created for each iteration. In contrast, array.push allocates a new element with a reference to the original array.
* **Assignment**: In both cases, the assignment operation (`o[++id] = o` or `a.push(a)`) updates the value associated with the key or at the end of the array.

**Pros and cons**

1. **Object approach (set prop on object)**:
	* Pros:
		+ Can be more efficient in certain situations, like when working with large datasets where objects are more compact.
		+ Allows for dynamic property creation without requiring a predefined structure.
	* Cons:
		+ Requires an explicit increment operation (`++id`) which can lead to slower performance due to the additional arithmetic.
		+ May incur additional overhead due to the object's internal data structures and caching mechanisms.
2. **Array.push**:
	* Pros:
		+ Often more efficient for simple use cases, as it leverages existing array implementation details (e.g., reuse of allocated memory).
		+ Can be faster due to reduced number of operations required (only one push operation instead of multiple property assignments).
	* Cons:
		+ Creates a new element with a reference to the original array, which can lead to increased memory usage and slower performance for large datasets.
		+ Does not allow for dynamic property creation without additional workarounds.

**Library or special JavaScript features**

There are no external libraries or special JavaScript features used in this benchmark.

**Other alternatives**

To explore alternative approaches, consider the following options:

* **Using `Array.prototype.forEach()`**: This method iterates over an array using a callback function, which might provide a more efficient alternative to `array.push`.
* **Implementing custom allocation strategies**: Depending on specific requirements, developing optimized allocation algorithms for objects and arrays could potentially outperform existing JavaScript engine implementations.
* **Profiling and optimization techniques**: Using profiling tools (e.g., Chrome DevTools) or applying optimization techniques (e.g., inlining, caching) to the benchmark code might further improve performance.

Keep in mind that the specific results may vary depending on the underlying JavaScript engine, hardware, and other factors.

Related benchmarks:

set prop on object vs array.push: no extra obj creation (version: 1)

Comparing performance of: set prop on object vs array.push

Created: 2 years ago by: Registered User

Jump to the latest result

set prop on object

array.push

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):