Benchmark: Push vs concat to alloc array

Tests:

push
let src_arr = [] for (let i = 0; i < 1024; ++i) { src_arr.push(-0) } for (let n = 0; n < 100; ++n) { let arr = [] for (let i = 0; i < 10*1024; ++i) { arr.push(-0) } }
concat
let src_arr = [] for (let i = 0; i < 1024; ++i) { src_arr.push(-0) } for (let n = 0; n < 100; ++n) { let arr = [] for (let i = 0; i < 10; ++i) { arr.concat(src_arr) } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
push
concat

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

**What is being tested?**

The provided benchmark tests two approaches to allocate an array with the right allocated size: `push` and `concat`. The goal is to determine which approach is faster.

**Options compared:**

There are two options being compared:

1. **Push**: Using the `push()` method to add elements to an existing array.
2. **Concat**: Using the `concat()` method to concatenate a new array with an existing one.

**Pros and Cons of each approach:**

* **Push:**
	+ Pros:
		- More efficient in terms of memory allocation, as it only allocates the necessary amount of memory for the new element.
		- Can be faster because it avoids the overhead of creating a new array.
	+ Cons:
		- Requires the existing array to already have enough capacity to accommodate the new element. If not, it will need to allocate more memory, which can lead to slower performance.
* **Concat:**
	+ Pros:
		- Does not require the existing array to have enough capacity, making it more suitable for large datasets or when the size of the new elements is unknown.
	+ Cons:
		- Can be slower because it requires creating a new array with the combined size of the original and new arrays.

**Library usage:**

There is no explicit library mentioned in the benchmark definition. However, the `concat()` method likely uses the underlying browser's engine to execute the operation.

**Special JavaScript feature or syntax:**

None mentioned. The code only uses standard JavaScript features such as loops, array operations, and conditionals.

**Other considerations:**

* The benchmark is run on a mobile device (iPhone), which may have different performance characteristics compared to desktop devices.
* The test cases use arrays of varying sizes, with the `push()` method allocating an array of 1024 elements and the `concat()` method concatenating an array of 10 times 1024 elements.

**Alternatives:**

Other approaches could include:

1. Using a data structure like a linked list or a stack to allocate memory.
2. Using a different allocation strategy, such as using a pool of pre-allocated arrays.
3. Compiling the JavaScript code to native machine code for performance optimization.

However, these alternatives may not be suitable for general-purpose programming and would likely require significant changes to the codebase.

Related benchmarks:

Push vs concat to alloc array (version: 0)

to allocate a array with the right allocated size, which one is the fastest ?

Comparing performance of: push vs concat

Created: 2 years ago by: Guest

Jump to the latest result

push

concat

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):