Benchmark: filter + join vs for + concat

Script Preparation code:

var arr = ["abc","123","fghfg","fdgfdgfd","dgfdgfdgfd","234344",false,"",undefined,34,"fdgfdg"]

Tests:

filter + join
const result = arr.filter(Boolean).join(" ");
for
let str = ""; for (let i = 0; i < arr.length; i++) { if (Boolean(arr[i])) { str += arr[i] + " "; } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
filter + join
for

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:127.0) Gecko/20100101 Firefox/127.0

Browser/OS: Firefox 127 on Windows

View result in a separate tab

Test name	Executions per second
filter + join	2410646.0 Ops/sec
for	4221223.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases.

**Benchmark Definition**

The website uses JSON to represent the benchmark, which is a common format for data exchange in web development. The benchmark consists of two parts:

1. **Script Preparation Code**: This section contains a JavaScript script that prepares the input data (an array `arr`) before running the benchmark.
2. **Html Preparation Code** (optional): This section contains an HTML code snippet, but it's empty for this particular benchmark.

In this case, there is no HTML preparation code, so we won't explore that aspect further.

**Test Cases**

The website defines two test cases:

1. **filter + join**: This test case measures the performance of filtering a boolean-ified array using the `filter()` method and then joining the resulting elements into a string using the `join()` method.
2. **for**: This test case measures the performance of iterating over the input array using a traditional `for` loop and concatenating the non-empty strings to form a result string.

**Library Usage**

There is no explicit library usage mentioned in the benchmark definition or test cases.

**Special JavaScript Features/Syntax**

There are two special features/syntaxes used in this benchmark:

1. **Boolean-ification**: In modern JavaScript, you can use the `Boolean()` function (or simply `true`/`false`) to convert a value to a boolean. This is done implicitly in the `filter()` method. The test case demonstrates how filtering an array with non-empty values using `filter(Boolean)` produces a new array containing only true values.
2. **Template literals** ( implicit ): Although not explicitly mentioned, the concatenation of strings with spaces (`arr[i] + " "` ) is done using template literals, which were introduced in JavaScript ES6.

**Options Comparison**

The test cases compare two approaches to achieve the same result:

1. **filter() + join**: This method uses a single function call (`arr.filter(Boolean).join(" ")`) that filters and then joins the array elements.
2. **for loop**: This approach iterates over the input array using a traditional `for` loop, concatenating non-empty strings to form the result.

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

1. **filter() + join**:
	* Pros: Concise, easy to read, and maintains consistency.
	* Cons: May create an intermediate array, which can be memory-intensive for large inputs.
2. **for loop**:
	* Pros: More control over the iteration process, allows for more complex logic.
	* Cons: Longer code snippet, may introduce performance overhead due to string concatenation.

**Alternatives**

Other alternatives could include:

1. `map()` method with an arrow function, e.g., `arr.filter(Boolean).map(x => x + " ").join(" ")`
2. `every()` method in combination with `map()`, e.g., `arr.map(x => Boolean(x)).reduce((acc, curr) => acc + (curr ? curr + " " : ""), "")`

These alternatives maintain the same logic as the original test cases but offer slightly different approaches to achieving the result.

In summary, the benchmark demonstrates two common JavaScript methods for filtering and joining arrays: the concise `filter() + join` approach versus a traditional `for` loop. Both methods have their pros and cons, which are considered when choosing an implementation depending on the specific requirements of your project.

Related benchmarks:

filter + join vs for + concat (version: 0)

Comparing performance of: filter + join vs for

Created: one year ago by: Guest

Jump to the latest result

filter + join

for

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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