Benchmark: filter: startsWith vs includes

Script Preparation code:

var sampleOptions = ['прицеп полуприцеп', 'прицеп картофелевоз'];
var options = Array.from(Array(1000)).map((_, i) => sampleOptions[i % 2]);

Tests:

startsWith
options.filter(option => option.startsWith('прицеп'));
includes
options.filter(option => option.includes('картофел'));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
startsWith
includes

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.27 Safari/537.36

Browser/OS: Chrome 96 on Linux

View result in a separate tab

Test name	Executions per second
startsWith	63180.5 Ops/sec
includes	38920.4 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The provided benchmark is comparing two approaches to filter an array of strings: `startsWith` and `includes`. The filtering criteria are based on the presence of certain substrings in the strings.

**Script Preparation Code**

The script preparation code generates an array of 1000 strings, with each string containing either "прицеп" or "картофелевоз". This is done using JavaScript's `Array.from()` method and a closure to map over the array and create new strings.

**Html Preparation Code**

There is no HTML preparation code provided, so we'll assume that the benchmark is running in a headless browser environment (e.g., Chrome Headless).

**Library Usage**

The `filter()` method is used in both test cases. The `filter()` method is a built-in JavaScript array method that takes a callback function as an argument. The callback function tests each element of the array against the specified condition, and returns a boolean value indicating whether the element passes the test. If the returned values are truthy, the elements are included in the new array; if they're falsy, they're excluded.

**Special JS Feature or Syntax**

There is no special JavaScript feature or syntax being used in this benchmark.

**Pros and Cons of Approaches**

Now, let's compare the two approaches:

1. **startsWith**: This approach uses the `startsWith()` method, which returns a boolean value indicating whether the string starts with the specified substring.
	* Pros:
		+ Can be faster for certain edge cases (e.g., when the filtering criteria are exact matches).
	* Cons:
		+ May be slower than `includes()` for more general filtering scenarios.
2. **includes**: This approach uses the `includes()` method, which returns a boolean value indicating whether the string includes the specified substring.
	* Pros:
		+ Can be faster for more general filtering scenarios (e.g., when the filtering criteria are not exact matches).
	* Cons:
		+ May be slower than `startsWith()` for certain edge cases.

**Other Considerations**

The choice between `startsWith` and `includes()` ultimately depends on the specific use case and performance requirements. If you need to filter an array of strings based on exact matches, `startsWith()` might be a better choice. However, if you're dealing with more general filtering scenarios or want to avoid potential performance differences, `includes()` might be a better option.

**Other Alternatives**

If you need to filter arrays in JavaScript, there are other alternatives to the `filter()` method:

1. **Array.prototype.every()**: This method returns a boolean value indicating whether all elements of the array pass the test.
2. **Array.prototype.some()**: This method returns a boolean value indicating whether at least one element of the array passes the test.

However, in this specific benchmark, `filter()` is being used to achieve a concise and readable way to filter arrays based on simple conditions.

Related benchmarks:

filter: startsWith vs includes (version: 3)

Comparing performance of: startsWith vs includes

Created: 3 years ago by: Registered User

Jump to the latest result

startsWith

includes

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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