Benchmark: push vs index - MeasureThat.net

Tests:

push
const messages = (new Array(500)).fill({hans: 'friedrich'}); const target = new Array(500); for (const msg of messages) target.push({ok: true});
index
const messages = (new Array(500)).fill({hans: 'friedrich'}); const target = new Array(500); for (let i = 0, len = messages.length; i < len; i++) target[i] = {ok: true};

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
push
index

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

I'll explain the benchmark being tested on MeasureThat.net.

The provided benchmark is testing two different approaches to push elements into an array in JavaScript: using the `push()` method and indexing directly to assign values.

**Push Method**

In this approach, the code uses the `push()` method to add elements to the end of an array. The example code pushes 500 objects with a specific property (`hans`) onto an empty array.

```javascript
const messages = (new Array(500)).fill({hans: 'friedrich'});
const target = new Array(500);
for (const msg of messages) {
    target.push({ok: true});
}
```

**Indexing Method**

The other approach uses indexing to assign values directly to the array. Instead of using `push()`, this code iterates over an array of 500 objects and assigns each object to a specific index in the target array.

```javascript
const messages = (new Array(500)).fill({hans: 'friedrich'});
const target = new Array(500);
for (let i = 0, len = messages.length; i < len; i++) {
    target[i] = {ok: true};
}
```

**Options Comparison**

The two approaches have different performance characteristics.

* The `push()` method is generally faster and more efficient because it avoids the overhead of indexing. However, it can lead to slower performance when dealing with very large arrays or arrays that need to be sorted or reversed.
* Indexing directly to assign values can be faster for smaller arrays or specific use cases where the array needs to be accessed by index.

**Pros and Cons**

* **Push Method:**
	+ Pros:
		- Generally faster
		- Less overhead compared to indexing
	+ Cons:
		- Can be slower for large arrays
		- May lead to slower performance when sorting or reversing the array
* **Indexing Method:**
	+ Pros:
		- Can be faster for smaller arrays or specific use cases
		- Avoids the overhead of `push()`
	+ Cons:
		- Slower for large arrays
		- More complex code due to indexing

**Library/ Framework Considerations**

There doesn't appear to be any libraries or frameworks being used in this benchmark. The examples are straightforward and demonstrate basic JavaScript syntax.

**Special JS Features/Syntax**

This benchmark does not use any special JavaScript features or syntax that would require explanation.

**Other Alternatives**

Some alternative approaches to pushing elements into an array include:

* Using `concat()` method: `target = target.concat(messages)`
* Using spread operator (`...`): `target = [...messages, {ok: true}]`
* Using a loop with a specific data structure (e.g., a typed array or a view)

These alternatives may offer different performance characteristics depending on the use case and requirements.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.102 Safari/537.36

Browser/OS: Chrome 98 on Windows

View result in a separate tab

Test name	Executions per second
push	180728.9 Ops/sec
index	277368.4 Ops/sec

Related benchmarks:

push vs index (version: 0)

Comparing performance of: push vs index

Created: 6 years ago by: Guest

Jump to the latest result

push

index

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):