Benchmark: Javascript: Case insensitive string comparison performance inc. regex

Script Preparation code:

var a = "John Doe"
var b = "john doe"
var c = "john smith"
var o = {
    sensitivity: 'base'
}

Tests:

toLowerCase()
a.toLowerCase() === b.toLowerCase()
localeCompare()
a.localeCompare(b,undefined,o)
toLowerCase() FAIL
c.toLowerCase() === b.toLowerCase()
localeCompare() FAIL
c.localeCompare(b,undefined,o)
Regex
new RegExp(a + "|" + b, "i");
Regex FAIL
new RegExp(c + "|" + b, "i");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
toLowerCase()
localeCompare()
toLowerCase() FAIL
localeCompare() FAIL
Regex
Regex FAIL

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Linux

View result in a separate tab

Test name	Executions per second
toLowerCase()	68655248.0 Ops/sec
localeCompare()	281324.2 Ops/sec
toLowerCase() FAIL	41516644.0 Ops/sec
localeCompare() FAIL	299076.0 Ops/sec
Regex	7187089.5 Ops/sec
Regex FAIL	7211958.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

Let's dive into the benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark is designed to test the performance of JavaScript string comparison methods: `toLowerCase()`, `localeCompare()` (with options), and regular expressions (`new RegExp`). The tests cover various scenarios, including case-insensitive comparisons, failures, and edge cases.

**Options Comparison**

There are three main approaches being compared:

1. **`toLowerCase()`**: This method converts both strings to lowercase before comparing them.
	* Pros: Simple, fast, and widely supported.
	* Cons: May not work correctly for non-ASCII characters or strings with accents.
2. **`localeCompare()` (with options)**: This method uses the browser's locale settings to perform a case-insensitive comparison.
	* Options:
		+ `sensitivity`: Can be set to `'base'`, `'variant'`, or `'custom'`.
			- Pros: More accurate than `toLowerCase()`, but slower and more complex.
			- Cons: May not work correctly in all locales or with certain characters.
3. **Regular Expressions (`new RegExp`)**: This method uses a regular expression to perform a case-insensitive comparison.
	* Pros: Highly customizable, fast, and reliable.
	* Cons: May be less intuitive for developers without regex expertise.

**Library/Functionality**

None of the test cases use any external libraries or functions other than built-in JavaScript methods (`toLowerCase()` and `localeCompare()`) and regular expressions (`new RegExp`).

**Special JS Features/Syntax**

There are no special JavaScript features or syntax being tested in this benchmark. The focus is on comparing different string comparison methods.

**Other Alternatives**

If you're interested in testing other string comparison methods, here are a few alternatives:

* `String.prototype.normalize()` with the `'NFD'` form to normalize strings before comparison.
* `DOM-based comparison libraries`, such as `string-regex` or `normalize.js`.
* `Custom comparison functions`, which can be used to test specific use cases or edge scenarios.

In summary, this benchmark provides a comprehensive evaluation of three popular JavaScript string comparison methods: `toLowerCase()`, `localeCompare()` with options, and regular expressions. The results can help developers understand the performance differences between these approaches and make informed decisions about which method to use in their applications.

Related benchmarks:

Javascript: Case insensitive string comparison performance inc. regex (version: 0)

Comparing performance of: toLowerCase() vs localeCompare() vs toLowerCase() FAIL vs localeCompare() FAIL vs Regex vs Regex FAIL

Created: one year ago by: Guest

Jump to the latest result

toLowerCase()

localeCompare()

toLowerCase() FAIL

localeCompare() FAIL

Regex

Regex FAIL

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):