Benchmark: push vs idx - MeasureThat.net

Tests:

push
const a = []; for (let i = 0; i < 8; i++) { a.push(i); } for (let i = 0; i < 8; i++) { a.pop(); }
idx
const a = []; a.length = 8; let len = 0; for (let i = 0; i < 8; i++) { a[len] = i; len++; } for (let i = 0; i < 8; i++) { len--; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
push
idx

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/605.1.15 (KHTML, like Gecko) Version/16.5.1 Safari/605.1.15

Browser/OS: Safari 16 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
push	28479840.0 Ops/sec
idx	27887068.0 Ops/sec

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

LLMs can make mistakes. Check important info.

**Overview of the Benchmark**

The provided benchmark compares two approaches for adding elements to an empty array in JavaScript:

1. `push()`: The traditional `push()` method, which adds one or more elements to the end of an array.
2. An alternative approach using indexing (`idx`), where the length of the array is set and then elements are added at that index.

**Options Compared**

The benchmark tests the performance of these two approaches:

* `push()`: Uses the traditional `push()` method to add 8 elements to the array.
* `idx`: Uses an alternative approach, where the length of the array is set, and then elements are added at that index.

**Pros and Cons of Each Approach**

**Push():**

Pros:

* Easy to read and understand
* Works with any JavaScript engine

Cons:

* May incur additional overhead due to the need to create a new element and add it to the array

**Idx:**

Pros:

* Can be more efficient, as it avoids the overhead of creating a new element and adding it to the array

Cons:

* Requires careful handling of edge cases (e.g., what happens when trying to access an index outside the bounds of the array)
* May not work with all JavaScript engines or versions

**Library Used**

None explicitly mentioned in the benchmark definition. However, it is likely that the `push()` method uses a library or built-in functionality to add elements to the array.

**Special JS Feature/Syntax**

The test case does not use any special JavaScript features or syntax that requires explanation.

**Other Considerations**

* The benchmark only tests the performance of these two approaches on an empty array. Real-world scenarios may involve other operations, such as removing elements or accessing elements at specific indices.
* The `idx` approach assumes a fixed length for the array. If the array is supposed to grow dynamically, this approach may not be suitable.

**Alternatives**

Other alternatives to test the performance of adding elements to an array include:

* Using a more complex data structure, such as a linked list or a tree
* Adding elements in batches rather than individually
* Using a different indexing scheme, such as using a `for` loop with an iterator instead of an index

**Benchmark Preparation Code**

The provided script preparation code is empty. This means that the benchmark does not require any specific setup or initialization before running.

```javascript
// No script preparation code needed
```

**Individual Test Cases**

Each test case consists of a single `benchmark definition` string, which contains the JavaScript code to be executed. The test name and other metadata are also provided:

```json
{
  "Benchmark Definition": "...",
  "Test Name": "push"
}
```

The benchmark results include information on the browser, device platform, operating system, executions per second, and test name for each iteration of the benchmark.

```json
[
  {
    // ...
    "ExecutionsPerSecond": 28479840.0,
    "TestName": "push"
  },
  {
    // ...
    "ExecutionsPerSecond": 27887068.0,
    "TestName": "idx"
  }
]
```

Related benchmarks:

push vs idx (version: 0)

Comparing performance of: push vs idx

Created: 2 years ago by: Guest

Jump to the latest result

push

idx

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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