Benchmark: Array population test

Script Preparation code:

var arraySize = 10000;
var iterations = arraySize + 100;

Tests:

new Array
var data = new Array(arraySize); for(var index = 0; index < iterations; index++){ data.unshift({}); }
brackets
var data = []; for(var index = 0; index < iterations; index++){ data.unshift({}); }
brackets with length
var data = []; data.length = arraySize; for(var index = 0; index < iterations; index++){ data.unshift({}); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new Array
brackets
brackets with length

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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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.

The provided JSON represents a benchmark test created on MeasureThat.net, which allows users to create and run JavaScript microbenchmarks. The benchmark is designed to measure the performance of different ways to populate an array in JavaScript.

**Benchmark Definition:**
The benchmark definition includes three test cases:

1. "new Array"
2. "brackets" (using square brackets `[]` to create an array)
3. "brackets with length" (using both square brackets and setting the initial length of the array using the `length` property)

**Options Compared:**

* The three test cases compare different ways to populate an array in JavaScript:
	+ Using the `new Array()` constructor (`new Array`)
	+ Using square brackets (`[]`)
	+ Using square brackets with the initial length set (`brackets with length`)
* These options are compared to determine which method is the fastest.

**Pros and Cons of Each Approach:**

1. **new Array():**
	* Pros:
		+ Simple and concise syntax
		+ Creates an array without any additional overhead
	* Cons:
		+ May require more memory allocation, leading to slower performance
2. **brackets ([]):**
	* Pros:
		+ Faster than `new Array()` due to less memory allocation overhead
		+ Can be more efficient for large arrays
	* Cons:
		+ Requires a valid array length or initial value to avoid errors
3. **brackets with length:**
	* Pros:
		+ Combines the benefits of both approaches (fast and concise syntax)
		+ Reduces memory allocation overhead compared to `new Array()`
	* Cons:
		+ Requires setting an initial length, which can lead to slower performance if not optimized

**Library or Special JS Feature:**
None of the test cases use any external libraries or special JavaScript features beyond basic syntax.

**Other Considerations:**

* The benchmark uses a simple script preparation code and HTML preparation code (null) to set up the test environment.
* The benchmark measures the execution time per second, which provides insight into the performance characteristics of each approach.
* The results are reported for different browsers and devices, allowing users to compare performance across various platforms.

**Alternatives:**
If you're interested in exploring alternative approaches or optimizing your own JavaScript array population methods, consider:

1. Using `Array.from()` instead of `new Array()`: This method creates an array from a specified iterable or array-like object.
2. Utilizing `Map` or other data structures for larger arrays: Depending on the specific use case, using other data structures like `Map` might be more efficient than traditional arrays.
3. Optimizing memory allocation and management: Techniques like caching or lazy loading can help reduce the overhead of creating and populating large arrays.

By understanding the trade-offs between different array population methods, you can make informed decisions about optimizing your JavaScript code for performance and scalability.

Related benchmarks:

Array population test (version: 0)

Comparing performance of: new Array vs brackets vs brackets with length

Created: 9 years ago by: Guest

Jump to the latest result

new Array

brackets

brackets with length

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):