Benchmark: Javascript: Case insensitive string comparison indexOf vs includes 2

Script Preparation code:

var words = Array.from({ length: 1000 }, (_, i) => `word${i + 1}`);
var searchString = "WORD512";
var searchStringRegex = new RegExp(searchString, 'i');

Tests:

toLowerCase_includes
const filteredCase1 = words.filter(word => word.toLowerCase().includes(searchString.toLowerCase()));
Regex_indexOf
const filteredCase2 = words.filter(word => searchStringRegex.test(word));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
toLowerCase_includes
Regex_indexOf

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) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Windows

View result in a separate tab

Test name	Executions per second
toLowerCase_includes	31322.2 Ops/sec
Regex_indexOf	39338.1 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 benchmarking scenario:

**Benchmark Definition**

The benchmark is designed to compare two approaches for case-insensitive string comparison in JavaScript: `indexOf` with regular expressions and `includes` method.

**Script Preparation Code**

The script preparation code creates an array of 1000 words, each word being a sequence of "word" followed by a number from 1 to 1000. It also sets up two variables:

* `searchString`: a string "WORD512"
* `searchStringRegex`: a regular expression created from `searchString` with the 'i' flag (case-insensitive)

The purpose of this script preparation code is to provide a consistent and controlled environment for the benchmarking test cases.

**Html Preparation Code**

There is no HTML preparation code provided, which suggests that this benchmark is focused on JavaScript performance alone.

**Individual Test Cases**

There are two individual test cases:

1. **toLowerCase_includes**: This test case uses the `filter()` method with a callback function that checks if a word includes the lowercase version of the search string (`searchString.toLowerCase()`) using the `includes()` method.
2. **Regex_indexOf**: This test case uses the `filter()` method with a callback function that checks if a word matches the regular expression created from the search string (`searchStringRegex`) for case-insensitive matching.

**Library and Purpose**

In both test cases, the `Array.prototype.filter()` method is used to filter the array of words. The `includes()` method is also used in one of the test cases. These are built-in JavaScript methods that do not require any external libraries.

There are no special JavaScript features or syntax mentioned in this benchmark.

**Options Compared**

The two options being compared are:

1. **toLowerCase_includes**: uses the `filter()` method with a callback function and the `includes()` method.
2. **Regex_indexOf**: uses the `filter()` method with a callback function and a regular expression for case-insensitive matching.

**Pros and Cons of Each Approach**

Here's a brief overview of each approach:

1. **toLowerCase_includes**:
	* Pros: simple, easy to read, and understand.
	* Cons: may be slower than using a regular expression due to the overhead of calling `toLowerCase()` on each string.
2. **Regex_indexOf**:
	* Pros: can provide more flexible matching options, such as matching an empty string or using flags like 'g' for global matching.
	* Cons: may be less readable and maintainable than using a simple callback function, especially for complex patterns.

**Other Considerations**

The benchmarking scenario assumes that the `filter()` method is optimized for performance, which might not always be the case in production code. Additionally, the use of `includes()` method might depend on the specific requirements of the application, such as finding multiple occurrences of a substring.

In terms of alternatives, there are other ways to perform string matching in JavaScript, such as using a library like `indexOf` or `match`, but these options are not explicitly mentioned in this benchmark.

Related benchmarks:

Javascript: Case insensitive string comparison indexOf vs includes 2 (version: 0)

Comparing performance of: toLowerCase_includes vs Regex_indexOf

Created: one year ago by: Guest

Jump to the latest result

toLowerCase_includes

Regex_indexOf

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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