Benchmark: Array.map vs preallocation ......

Tests:

dynamic
const array = []; for (let i=0; i<10000000; i++) { array[i] = 1; }
Preallocation
const array = new Array(10000000); for (let i=0; i<10000000; i++) { array[i] = i; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
dynamic
Preallocation

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what's being tested.

**Benchmark Definition**

The benchmark is defined by the `Script Preparation Code` field, which is currently empty. This means that the test script itself will be generated dynamically for each execution.

However, we can look at the individual test cases to understand what's being compared:

* The first test case, "dynamic", uses a loop to create an array of 10 million elements and assigns the value 1 to each element.
* The second test case, "Preallocation", creates an array with 10 million pre-allocated elements using `new Array(10000000)`, then loops through it to assign values.

**Options being compared**

The benchmark is comparing two approaches:

1. **Dynamic allocation**: Creating the array dynamically using a loop, where each element is assigned individually.
2. **Preallocation**: Pre-allocating the entire array with the desired number of elements and then looping through it to assign values.

**Pros and Cons**

**Dynamic Allocation (Test Case: "dynamic")**

Pros:

* Flexibility: allows for dynamic changes in the size of the array
* Memory efficiency: only allocates memory as needed

Cons:

* Potential performance overhead due to repeated allocations and assignments
* May result in slower execution times compared to preallocation

**Preallocation (Test Case: "Preallocation")**

Pros:

* Reduced overhead from repeated allocations and assignments
* Faster execution times due to batch processing of elements

Cons:

* Fixed memory allocation for the entire array, which can lead to memory waste if not fully utilized
* Less flexibility in terms of dynamic changes

**Other Considerations**

Both approaches have their trade-offs. Dynamic allocation is more flexible but may incur performance overhead, while preallocation provides faster execution times but can result in wasted memory.

**Library/Feature Description (None)**

There are no libraries or special JavaScript features being used in these benchmark tests.

**Alternative Approaches**

Other alternatives to consider:

* **Using `Array.prototype.map()`**: This method can be used instead of dynamic allocation for creating arrays. It's often faster and more concise, but may not provide the same level of control as preallocation.
* **Using `Buffer` or `TypedArray`**: For large datasets, using `Buffer` or `TypedArray` objects can provide better performance and memory efficiency compared to traditional JavaScript arrays.

Keep in mind that these alternative approaches would require modifications to the benchmark script to accommodate them.

Latest run results:

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

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_1_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.1.1 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 17 on iOS 17.1.1

View result in a separate tab

Test name	Executions per second
dynamic	34.6 Ops/sec
Preallocation	14.2 Ops/sec

Related benchmarks:

Array.map vs preallocation ...... (version: 0)

Comparing performance of: dynamic vs Preallocation

Created: one year ago by: Guest

Jump to the latest result

dynamic

Preallocation

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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