Benchmark: Javascript: Case insensitive string comparison performance en-US accent

Script Preparation code:

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

Tests:

toLowerCase()
a.toLowerCase() === b.toLowerCase()
localeCompare()
a.localeCompare(b, 'en-US', o)
toLowerCase() FAIL
c.toLowerCase() === b.toLowerCase()
localeCompare() FAIL
c.localeCompare(b, 'en-US' ,o)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 7 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:143.0) Gecko/20100101 Firefox/143.0

Browser/OS: Firefox 143 on Windows

View result in a separate tab

Test name	Executions per second
toLowerCase()	2456926208.0 Ops/sec
localeCompare()	478556.7 Ops/sec
toLowerCase() FAIL	2484977152.0 Ops/sec
localeCompare() FAIL	498941.7 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 and explain what's being tested.

**Benchmark Overview**

The benchmark compares the performance of two string comparison methods in JavaScript: `toLowerCase()` and `localeCompare()`. The tests are designed to be case-insensitive, meaning that both "John Doe" and "john doe" should be considered equal.

**Options Compared**

There are four test cases:

1. `toLowerCase()`: This method converts both input strings to lowercase before comparing them.
2. `localeCompare(b, 'en-US', o)`: This method uses the locale settings and options (`o`) to perform a case-insensitive comparison. The `'en-US'` argument specifies that the comparison should be done in English (United States) culture, which is supposed to ignore accent marks.
3. `toLowerCase() FAIL`: This test case checks if the `toLowerCase()` method fails for a different string pair ("john smith" and "John Doe").
4. `localeCompare() FAIL`: This test case checks if the `localeCompare()` method fails for the same reasons as the previous one.

**Pros and Cons of Each Approach**

1. **`toLowerCase()`**: Pros:
	* Simple and widely supported.
	* Fast execution time.
Cons:
	* May not work correctly with non-ASCII characters or accents (depending on the locale).
2. **`localeCompare(b, 'en-US', o)`**: Pros:
	+ Takes into account accented characters and handles non-English locales.
	+ Can be more accurate for case-insensitive comparisons.
Cons:
	* May have performance overhead due to locale settings.
	* Requires a good understanding of locale-specific settings.

**Library: Intl**

The `localeCompare()` method uses the Internationalization API (Intl) in JavaScript, which provides access to locale-specific formatting and comparison functions. The Intl object is part of the ECMAScript standard and is widely supported across modern browsers.

**Special JS Features/Syntax**

There are no special features or syntax mentioned in this benchmark. However, it's worth noting that some browsers may have specific nuances for string comparisons (e.g., Unicode normalization).

**Other Alternatives**

If you need to perform case-insensitive string comparisons in JavaScript, you can also use:

1. **`String.prototype.normalize()` + `toLowerCase()`**: This method normalizes the input strings before converting them to lowercase.
2. **`RegExi.match()` with a case-insensitive flag**: Some regex libraries or frameworks provide support for case-insensitive matching.

Keep in mind that these alternatives might not be as efficient or widely supported as the Intl API, which is specifically designed for locale-aware string comparisons.

Related benchmarks:

Javascript: Case insensitive string comparison performance en-US accent (version: 0)

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

Created: 3 years ago by: Guest

Jump to the latest result

toLowerCase()

localeCompare()

toLowerCase() FAIL

localeCompare() FAIL

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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