Benchmark: For loop vs filter

Script Preparation code:

var finished = [];
var live = [];

for(i=0; i<=300; i++){
	finished.push(i.toString())
}
                 
for(i=0; i<=1000; i++){
	live.push(i.toString())
}

Tests:

Test for loop
var arr2 = []; var finishedLength = finished.length; for(i=0; i<=finishedLength; i++){ if (live.includes(finished[i])) { arr2.push(finished[i]) } }
Test filter
var arr3 = finished.filter( (f) => live.includes(f) )

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Test for loop
Test filter

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 benchmark and explain what's being tested.

**What is being tested?**

The provided JSON represents two microbenchmarks: "For loop vs filter". The goal of these benchmarks is to compare the performance of two different approaches for filtering an array of numbers:

1. **For Loop**: The first approach uses a traditional `for` loop to iterate over the `finished` array and check if each element exists in the `live` array using the `includes()` method.
2. **Filter Method**: The second approach uses the `filter()` method with a callback function to create a new array that includes only the elements present in both `finished` and `live`.

**Options compared**

These two approaches have different performance characteristics:

* **For Loop**: This approach iterates over the entire `finished` array, which has 300 elements. For each iteration, it checks if the current element exists in the `live` array using `includes()`. This results in a linear search, making it less efficient for large arrays.
* **Filter Method**: This approach creates a new array with only the desired elements. The `filter()` method is optimized to perform a binary search on the original array, which makes it more efficient than the linear search used by the `for` loop.

**Pros and Cons**

Here are the pros and cons of each approach:

* **For Loop**:
	+ Pros: Easy to understand and implement.
	+ Cons: Linear search makes it less efficient for large arrays.
	+ Additional Considerations: This approach can be slower due to the overhead of the `includes()` method, which has to iterate over the entire array in some browsers (like Safari).
* **Filter Method**:
	+ Pros: More efficient for large arrays, optimized binary search.
	+ Cons: May have a higher memory overhead due to creating a new array.

**Library and syntax**

In this benchmark, we don't see any external libraries being used. However, the `filter()` method is a built-in JavaScript function that is supported by most modern browsers.

The only notable syntax feature is the use of template literals (`f.toString()`) in some of the test cases. This is a relatively recent feature introduced in ECMAScript 2015 (ES6), which allows for more concise string interpolation.

**Other alternatives**

If you're looking for alternative filtering approaches, here are a few options:

* **Splice Method**: Instead of using `includes()` or `filter()`, you could use the `splice()` method to remove elements from the original array that don't match the filter criteria. This approach has a higher overhead due to array modification.
* **Array.prototype.some() Method**: Another alternative is to use the `some()` method, which returns `true` if at least one element in the array matches the callback function.

Keep in mind that these alternatives may have different performance characteristics compared to the `filter()` method.

Related benchmarks:

For loop vs filter (version: 0)

Comparing performance of: Test for loop vs Test filter

Created: 6 years ago by: Guest

Jump to the latest result

Test for loop

Test filter

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):