Benchmark: JS Object Creation vs Pooling

Script Preparation code:

const n = 10000
var arr = new Array(n).fill(0);
for (let i = 0; i < n; i++) {
  arr[i] = i;
}

AخA
 
const n = 10000var arr = new Array(n).fill(0);for (let i = 0; i < n; i++) {  arr[i] = i;}

Tests:

Dynamic Creation

const result = [];
for (let i = 0; i < arr.length; i++) {
  result.push({
    x: arr[i],
    y: arr[i] + 1
  });
}

 
const result = [];for (let i = 0; i < arr.length; i++) {  result.push({    x: arr[i],    y: arr[i] + 1  });}

Pooling

const result = [];
const obj = { x: 0, y: 0 };
for (let i = 0; i < arr.length; i++) {
  obj.x = arr[i];
  obj.y = arr[i] + 1;
  result.push(obj);
}

 
const result = [];const obj = { x: 0, y: 0 };for (let i = 0; i < arr.length; i++) {  obj.x = arr[i];  obj.y = arr[i] + 1;  result.push(obj);}

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Experimental features:

Memory measurements supported only in Chrome.
For precise memory measurements Chrome must be launched with --enable-precise-memory-info flag.
More information: Monitoring JavaScript Memory

Test case name	Result
Dynamic Creation
Pooling

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Linux

View result in a separate tab

Test name	Executions per second
Dynamic Creation	6140.5 Ops/sec
Pooling	11826.9 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

Let's break down the JavaScript microbenchmark you provided.

Benchmark Definition

The benchmark tests two approaches to create arrays of objects:

Pooling: This approach creates an initial array arr with 10,000 elements and fills it with zeros. Then, for each element in the array, a new object is created and added to an empty result array.
Dynamic Creation: In this approach, an empty result array is created initially. For each element in the arr array, a new object is created on the fly using the elements from arr, and then that object is pushed into the result array.

Options Compared

The benchmark compares two options:

Pooling: Creates an initial array of objects and then creates new objects within that array.
Dynamic Creation: Creates new objects directly within the result array, without creating a pre-allocated array.

Pros and Cons

Pooling:
- Pros: Can be faster because it avoids the overhead of creating a large number of objects on the fly.
- Cons: Requires more memory upfront to create the initial array, which may not be desirable in all scenarios.
Dynamic Creation:
- Pros: Uses less memory upfront and can be more suitable for scenarios where the number of objects is not known beforehand.
- Cons: Can be slower because it involves creating new objects on the fly.

Library Usage

There are no libraries explicitly mentioned in this benchmark, but it's worth noting that if a library were used to implement these approaches (e.g., Lodash or Array.prototype.map()), the results might differ due to the additional overhead of the library.

Special JS Features/Syntax

None of the provided benchmark code uses any special JavaScript features or syntax. It only uses basic JavaScript constructs like arrays, loops, and object creation.

Alternative Approaches

Other approaches to creating arrays of objects could include:

Using Array.prototype.map(): Instead of using a loop to create new objects, you could use the map() method to create an array of transformed objects. This approach is often more concise and efficient.
Using a library like Lodash's map() function: Similar to the previous suggestion, using a library's implementation of map() can provide a performance boost compared to the basic JavaScript implementation.

Keep in mind that these alternative approaches might have different performance characteristics depending on the specific use case and requirements.

LLMs can make mistakes. Check important info.

Let's break down the JavaScript microbenchmark you provided.

**Benchmark Definition**

The benchmark tests two approaches to create arrays of objects:

1. **Pooling**: This approach creates an initial array `arr` with 10,000 elements and fills it with zeros. Then, for each element in the array, a new object is created and added to an empty result array.
2. **Dynamic Creation**: In this approach, an empty result array is created initially. For each element in the `arr` array, a new object is created on the fly using the elements from `arr`, and then that object is pushed into the result array.

**Options Compared**

The benchmark compares two options:

* **Pooling**: Creates an initial array of objects and then creates new objects within that array.
* **Dynamic Creation**: Creates new objects directly within the result array, without creating a pre-allocated array.

**Pros and Cons**

* **Pooling**:
	+ Pros: Can be faster because it avoids the overhead of creating a large number of objects on the fly.
	+ Cons: Requires more memory upfront to create the initial array, which may not be desirable in all scenarios.
* **Dynamic Creation**:
	+ Pros: Uses less memory upfront and can be more suitable for scenarios where the number of objects is not known beforehand.
	+ Cons: Can be slower because it involves creating new objects on the fly.

**Library Usage**

**Special JS Features/Syntax**

None of the provided benchmark code uses any special JavaScript features or syntax. It only uses basic JavaScript constructs like arrays, loops, and object creation.

**Alternative Approaches**

Other approaches to creating arrays of objects could include:

* **Using `Array.prototype.map()`**: Instead of using a loop to create new objects, you could use the `map()` method to create an array of transformed objects. This approach is often more concise and efficient.
* **Using a library like Lodash's `map()` function**: Similar to the previous suggestion, using a library's implementation of `map()` can provide a performance boost compared to the basic JavaScript implementation.

Keep in mind that these alternative approaches might have different performance characteristics depending on the specific use case and requirements.

Related benchmarks:

JS Object Creation vs Pooling (version: 0)

Comparing performance of: Dynamic Creation vs Pooling

Created: one year ago by: Registered User

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