Benchmark: Preinitialized array size vs Push operations to an empty one.

Tests:

Preinitialized size - large difference
let arr = new Array(100000) for (var i=0; i<1000; i++) { arr[i] = Math.random; } arr = arr.slice(0, 1000)
Push
let arr =[] for (var i=0; i<1000; i++) { arr.push(Math.random); }
Preinitialized size - small difference
let arr = new Array(1200) for (var i=0; i<1000; i++) { arr[i] = Math.random; } arr = arr.slice(0, 1000)
Preinitilized size - no difference
let arr = new Array(1000) for (var i=0; i<1000; i++) { arr[i] = Math.random; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Preinitialized size - large difference
Push
Preinitialized size - small difference
Preinitilized size - no difference

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.54 Safari/537.36

Browser/OS: Chrome 95 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Preinitialized size - large difference	4499.9 Ops/sec
Push	7527.0 Ops/sec
Preinitialized size - small difference	8231.4 Ops/sec
Preinitilized size - no difference	8265.1 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark measures the performance of two approaches: preinitializing an array with a specific size and using the `push` method to add elements to an empty array.

**Preinitialized Array Size vs Push Operations**

The tests compare the execution time of two scenarios:

1. **Preinitialized size - large difference**: The array is initialized with 100,000 elements and then sliced to keep only the first 1,000 elements. This creates a significant amount of unnecessary work.
2. **Push**: The array starts empty and uses `push` to add 1,000 random elements to it.
3. **Preinitialized size - small difference**: Similar to the previous test, but the array is initialized with 12,000 elements instead of 100,000.
4. **Preinitialized size - no difference**: The array is initialized with 1,000 elements and then sliced to keep only the first 1,000 elements.

**Options Compared**

The two main options being compared are:

* Preinitializing an array with a specific size
* Using `push` method to add elements to an empty array

**Pros and Cons of Each Approach**

**Preinitialized Array Size:**

Pros:

* Can lead to better cache locality, as the entire array is initialized at once.
* May reduce the number of allocations required.

Cons:

* Creates unnecessary work if only a subset of elements is needed (as in the "large difference" test).
* May require more memory upfront.

**Push Method:**

Pros:

* Only creates elements as needed, reducing unnecessary work.
* Flexibility to add or remove elements dynamically.

Cons:

* Can lead to slower execution times due to the overhead of creating and manipulating arrays.
* Requires more memory allocations over time.

**Library Used**

None mentioned in the provided benchmark definition. However, some libraries might be used for parsing the HTML preparation code or executing the test cases (e.g., JavaScript engines like V8).

**Special JS Features or Syntax**

No special features or syntax are mentioned in the benchmark definition. If there were any, they would likely be related to performance optimization techniques.

**Other Alternatives**

To measure similar performance characteristics, you might consider using other methods:

* Using a different data structure, such as an array-like object or a linked list.
* Implementing a custom allocator for arrays.
* Using parallel processing or multi-threading to execute the tests in multiple threads.

Keep in mind that these alternatives would likely have significant changes to the benchmark code and might not produce comparable results.

Related benchmarks:

Preinitialized array size vs Push operations to an empty one. (version: 1)

Comparing performance of: Preinitialized size - large difference vs Push vs Preinitialized size - small difference vs Preinitilized size - no difference

Created: 5 years ago by: Registered User

Jump to the latest result

Preinitialized size - large difference

Push

Preinitialized size - small difference

Preinitilized size - no difference

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):