Benchmark: yoyoyo - MeasureThat.net

Script Preparation code:

var over1 = [{
id: 'dtm',
isVisible: false
},{
id: 'nap',
isVisible: true
}];

var over2 = [{
id: 'dtm',
isVisible: true
}];

Tests:

a
return over1.filter(el => { return !over2.find(item => item.id === el.id); }).map(layer => layer.id);
b
return over1.filter(el => { return !over2.some(item => item.id === el.id); }).map(layer => layer.id);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
a
b

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.

I'll break down the provided benchmark and explain what's being tested, compared options, pros and cons, and other considerations.

**Benchmark Overview**

The benchmark is designed to measure the performance of JavaScript code that filters an array of objects based on their existence in another array. The test cases are comparing two approaches:

1. `filter()` with a callback function that uses `find()`
2. `filter()` with a callback function that uses `some()`

**Script Preparation Code**

The script preparation code defines two arrays, `over1` and `over2`. `over1` contains objects with an `id` property and an `isVisible` property set to `false` or `true`. `over2` contains only one object with the same `id` property.

**Html Preparation Code**

The html preparation code is empty, which means that no HTML document is being prepared for this benchmark. This suggests that the focus is solely on JavaScript performance optimization.

**Individual Test Cases**

There are two test cases:

1. **Test Case "a"**
```javascript
return over1.filter(el => {
  return !over2.find(item => item.id === el.id);
}).map(layer => layer.id);
```
This code uses the `find()` method to search for an object in `over2` with the same `id` property as the current element in `over1`. If no such object is found, it returns `true`, and if found, it returns `false`. The filter then removes all elements from `over1` that return `false`.

**Test Case "b"**
```javascript
return over1.filter(el => {
  return !over2.some(item => item.id === el.id);
}).map(layer => layer.id);
```
This code uses the `some()` method to search for any object in `over2` with the same `id` property as the current element in `over1`. If no such object is found, it returns `true`, and if found, it returns `false`. The filter then removes all elements from `over1` that return `false`.

**Comparison**

The test cases compare the performance of these two approaches:

* `find()` vs. `some()`

**Pros and Cons**

Here's a brief summary of each approach:

### Find()

* Pros:
	+ More precise, as it will only find an exact match
	+ May be faster for small arrays
* Cons:
	+ More memory-intensive, as it needs to store the entire array in memory
	+ Can be slower for large arrays due to the overhead of searching

### Some()

* Pros:
	+ Faster and more memory-efficient, as it only checks if any match is found
	+ Suitable for large arrays where a single match would be sufficient
* Cons:
	+ May return false positives if an object with the same `id` property exists in the array but not exactly matching
	+ Requires careful consideration to ensure correct results

**Library:**

There are no libraries mentioned in the benchmark, so there's nothing specific to note.

**Special JS Feature/Syntax:**

None of the code uses any special JavaScript features or syntax beyond standard `filter()`, `find()`, and `some()` methods.

Related benchmarks:

yoyoyo (version: 1)

Comparing performance of: a vs b

Created: 8 years ago by: Registered User

Jump to the latest result

a

b

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):