Benchmark: Push one by one vs slice and fill array

Tests:

push
let src_arr = [] for (let i = 0; i < 1024; ++i) { src_arr.push(-1.1) } for (let n = 0; n < 100; ++n) { let arr = [] for (let i = 0; i < 1024; ++i) { arr.push(-0) } }
slice & Fill
let src_arr = [] for (let i = 0; i < 1024; ++i) { src_arr.push(-1.1) } for (let n = 0; n < 100; ++n) { let arr = src_arr.slice() arr.fill(-0) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
push
slice & Fill

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the provided JSON and explain what's being tested, the different approaches compared, their pros and cons, and other considerations.

**Benchmark Definition**

The benchmark definition is a set of instructions that defines the test case. In this case, there are two test cases: "Push one by one vs slice and fill array". The description explains that the goal is to allocate an array with the right allocated size and determine which approach is faster.

**Script Preparation Code**

There is no script preparation code provided in the JSON, which means that the browser's JavaScript engine will generate the initial array and perform the push operations or slice and fill operations as specified in the benchmark definition.

**Individual Test Cases**

There are two test cases:

1. **Push one by one**: This test case creates an empty array `src_arr` and then pushes 1024 elements of value `-1.1` into it using a single loop. After that, it creates another array `arr` with the same size (1024) and fills it with value `-0` using the `fill()` method.
2. **Slice and Fill**: This test case creates an empty array `src_arr` and then pushes 1024 elements of value `-1.1` into it. Then, it creates another array by slicing a copy of `src_arr` and fills it with value `-0` using the `fill()` method.

**Comparison**

The two approaches are compared in terms of performance (measured in executions per second). The test case with "Push one by one" is expected to be slower than the test case with "Slice and Fill".

**Pros and Cons**

1. **Push one by one**:
	* Pros: This approach allows for more control over the array elements, which might be beneficial for certain use cases.
	* Cons: It can be slower because JavaScript has to push each element individually, which involves allocating memory and updating the array's length.
2. **Slice and Fill**:
	* Pros: This approach is often faster because it allows the browser's JavaScript engine to optimize the allocation of memory and fill the array in a single operation.
	* Cons: It can be less flexible because it requires slicing an existing array, which might not always be desirable.

**Other Considerations**

* The test case assumes that the allocated size of the arrays is equal (1024), but this may not always be the case. In general, it's a good practice to check if the array length can be safely inferred from the context.
* The `fill()` method is used in both test cases, which might be an optimization provided by the browser's JavaScript engine.

**Libraries and Special JS Features**

There are no libraries or special JavaScript features mentioned in the JSON. However, it's worth noting that some browsers (e.g., WebAssembly) provide specialized APIs for memory allocation and manipulation, but these are not relevant to this specific benchmark.

**Alternatives**

Other approaches could be considered, such as:

* Using a native array allocation function (e.g., `Array.alloc()` in Node.js) instead of the built-in `push` method.
* Using a library or framework that provides optimized array allocation and manipulation APIs (e.g., Apache Commons Lang).
* Implementing custom memory allocation and deallocation mechanisms using WebAssembly or other low-level APIs.

However, these alternatives are not relevant to this specific benchmark, which focuses on comparing the performance of basic JavaScript operations.

Related benchmarks:

Push one by one vs slice and fill array (version: 0)

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

Comparing performance of: push vs slice & Fill

Created: 2 years ago by: Guest

Jump to the latest result

push

slice & Fill

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):