Benchmark: New array vs reuse array

Tests:

New array
for( let i = 0; i < 10000; i++ ) { const node = { children: [] }; const nodes = i % 2 === 0 ? [ 1 ] : []; for( let j = 0; j < nodes.length; j++ ) { node.children[ i ] = nodes[ j ]; } }
Reuse array
const emptyArray = []; for( let i = 0; i < 10000; i++ ) { const node = { children: [] }; const nodes = i % 2 === 0 ? [ 1 ] : emptyArray; for( let j = 0; j < nodes.length; j++ ) { node.children[ i ] = nodes[ j ]; } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
New array
Reuse array

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.127 Safari/537.36

Browser/OS: Chrome 100 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
New array	1133.6 Ops/sec
Reuse array	1135.9 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its test cases.

**What is being tested?**

The website "MeasureThat.net" is measuring the performance of two different approaches for creating a nested data structure in JavaScript:

1. **New array**: Creating a new array with 10,000 elements, where each element is another object containing an array of nodes.
2. **Reuse array**: Using an existing empty array and modifying it by assigning new values to its indices.

**Options compared**

The two test cases are comparing the performance of these two approaches:

Pros and Cons:

* **New array**:
	+ Pros: Easy to understand, straightforward implementation, no potential memory leaks.
	+ Cons: Creating a new array can be expensive in terms of memory allocation and copying data.
* **Reuse array**:
	+ Pros: Reuses existing memory, potentially faster and more efficient than creating a new array.
	+ Cons: Can lead to memory fragmentation, and if not done carefully, might result in performance issues due to unnecessary relocations.

Other considerations:

* Both approaches assume that the JavaScript engine will be able to optimize the code for better performance. However, the actual performance may vary depending on factors like browser version, hardware, and OS.
* The test cases are measuring the number of executions per second (ExecutionsPerSecond), which is a good metric for benchmarking performance.

**Library usage**

There is no explicit library mentioned in the provided code snippets. However, it's likely that the JavaScript engine being used by MeasureThat.net is optimized to work with native JavaScript syntax.

**Special JS feature or syntax**

There are some specific features and syntax used in these test cases:

* The use of `let` and `const` keywords for variable declaration.
* The use of template literals (`\r\n`) for string concatenation.
* The use of array indexing (`nodes[ j ]`) to access elements.

**Alternatives**

If you're interested in exploring alternative approaches or optimizations, here are a few options:

* Use a library like **Lodash**, which provides optimized functions for common tasks, such as array manipulation and object creation.
* Consider using a more functional programming approach, like using recursion or map/reduce operations to create the nested data structure.
* Experiment with different browser versions, hardware configurations, and OS platforms to see how performance varies.

Keep in mind that these alternatives may not be directly applicable to this specific benchmark test case, but they can help you explore other optimization techniques or approaches.

Related benchmarks:

New array vs reuse array (version: 0)

Comparing performance of: New array vs Reuse array

Created: 2 years ago by: Registered User

Jump to the latest result

New array

Reuse array

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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