Benchmark: Array filter vs. for loop (fixed2)

Script Preparation code:

var arr = [1,2,3,4,5,6,7,8,9,0], farr;

Tests:

Filter
farr = arr.filter(function(item) { return (item>4); } );
For
for (var i=0;i<arr.length;i++) { if (arr[i]<5) continue; farr.push(arr[i]); }
For 2
for (var i=0;i<arr.length;i++) { if (arr[i]>4) farr.push(arr[i]); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Filter
For
For 2

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, and their pros and cons.

**Benchmark Overview**

The test measures the performance difference between three approaches to filter an array in JavaScript:

1. `Array.filter()`
2. `for` loop with a conditional statement
3. `for` loop without a conditional statement (the second one is similar to the first, but without filtering)

**Script Preparation Code**

The script preparation code sets up an array `arr` containing 10 elements and creates a variable `farr` that will be used as the output array.

```javascript
var arr = [1,2,3,4,5,6,7,8,9,0], farr;
```

**Html Preparation Code**

There is no HTML preparation code provided, which means this benchmark only focuses on JavaScript performance.

**Test Cases**

The three test cases are:

1. **Filter**: This test uses the `Array.filter()` method to create a new array that includes only elements greater than 4.
```javascript
farr = arr.filter(function(item) { return (item>4); });
```
2. **For**: This test uses a traditional `for` loop with an if statement to push elements into the output array `farr`.
```javascript
for (var i=0;i<arr.length;i++) {
  if (arr[i]<5) continue;
  farr.push(arr[i]);
}
```
3. **For 2**: This test is similar to the previous one, but without the conditional statement (`if (arr[i]<5)`). It simply pushes all elements into the output array `farr`.
```javascript
for (var i=0;i<arr.length;i++) {
  farr.push(arr[i]);
}
```
**Library: `Array.prototype.filter()`**

The `Array.prototype.filter()` method is a built-in JavaScript method that creates a new array with only the elements that pass the test implemented by the provided function. In this case, the filter function checks if an element is greater than 4.

**Special JS Feature/Syntax**

There is no special JavaScript feature or syntax used in these tests. They are straightforward implementations of basic programming concepts.

**Alternatives**

Other approaches to filtering arrays could include:

* Using `Array.prototype.every()` method with a callback function
* Using `Array.prototype.map()` method followed by `Array.prototype.slice()`
* Using `Array.prototype.reduce()` method (although this would be less efficient)

These alternatives might be interesting for further benchmarking, but they are not the focus of this specific test case.

Related benchmarks:

Array filter vs. for loop (fixed2) (version: 0)

Comparing performance of: Filter vs For vs For 2

Created: 6 years ago by: Guest

Jump to the latest result

Filter

For

For 2

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):