Benchmark: Javascript: Case insensitive string comparison performance

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)

Historical Performance Data aggregated from 96 community runs

Desktop Results:

Chrome 87 runs

toLowerCase()

14.0M/s

toLowerCase() FAIL

12.4M/s

localeCompare()

254K/s

localeCompare() FAIL

250K/s

Fastest: toLowerCase() (56.1x faster)

View exact numbers

✓ toLowerCase(): 14,003,934 ops/sec
• toLowerCase() FAIL: 12,447,962 ops/sec
• localeCompare(): 253,863 ops/sec
• localeCompare() FAIL: 249,508 ops/sec

Firefox 9 runs

toLowerCase() FAIL

1366.1M/s

toLowerCase()

1356.3M/s

localeCompare() FAIL

337K/s

localeCompare()

310K/s

Fastest: toLowerCase() FAIL (4404.0x faster)

View exact numbers

✓ toLowerCase() FAIL: 1,366,059,008 ops/sec
• toLowerCase(): 1,356,336,768 ops/sec
• localeCompare() FAIL: 337,272 ops/sec
• localeCompare(): 310,187 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

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: 5 months ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_7 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.3 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 26 on iOS 18.7

View result in a separate tab

toLowerCase()

284.5M/s

toLowerCase() FAIL

252.3M/s

localeCompare()

199K/s

localeCompare() FAIL

176K/s

View exact numbers

Test name	Executions per second
✓ toLowerCase()	284,492,544 Ops/sec
toLowerCase() FAIL	252,288,192 Ops/sec
localeCompare()	198,610 Ops/sec
localeCompare() FAIL	176,212 Ops/sec

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

LLMs can make mistakes. Check important info.

Measuring JavaScript performance is crucial for optimizing and debugging code. Let's break down the provided benchmark definition and test cases to understand what's being tested.

**Benchmark Definition**

The benchmark measures the performance of case-insensitive string comparison using two approaches: `toLowerCase()` and `localeCompare()`. The script preparation code defines three strings with different casing (`John Doe`, `john doe`, and `john smith`) and an object with a single property, `sensitivity`, set to `'base'`.

**Test Cases**

There are four test cases:

1. `toLowerCase()`: Tests if the string comparison using `toLowerCase()` returns true for equal strings.
2. `localeCompare(b,undefined,o)`: Tests if the locale-aware string comparison using `localeCompare()` with default options (`b`, `undefined`, and an object with `sensitivity` set to `'base'`) returns true for equal strings.
3. `toLowerCase() FAIL`: This test case is similar to the first one but uses a different string (`john smith`). The purpose of this test case is likely to detect false positives where `toLowerCase()` might incorrectly return true due to the casing difference between `a` and `c`.
4. `localeCompare() FAIL`: Similar to the third test case, this test detects potential issues with locale-aware comparison.

**Options Compared**

Two main options are compared:

* `toLowerCase()`: A simple string normalization method that converts strings to lowercase.
* `localeCompare(b,undefined,o)`: A locale-aware string comparison method that takes into account regional differences in character ordering and casing.

**Pros and Cons of Each Approach**

1. **`toLowerCase()`**:
	* Pros: Simple, fast, and widely supported across browsers.
	* Cons: Loses original casing information, which might lead to unexpected behavior or false positives.
2. **`localeCompare(b,undefined,o)`**:
	* Pros: Preserves original casing information, takes into account regional differences, and is designed for locale-aware comparisons.
	* Cons: More complex, slower, and may have variations in performance across different browsers and locales.

**Library and Purpose**

The `localeCompare()` method uses the ECMAScript Internationalization API, which provides a way to compare strings in a locale-aware manner. The purpose of this method is to provide a standardized way of handling character ordering and casing differences across regions.

**Special JS Feature or Syntax**

None are explicitly mentioned in the provided benchmark definition.

**Other Alternatives**

While not tested in this specific benchmark, other alternatives for case-insensitive string comparison include:

* `normalize()` followed by `localeCompare()`
* Using a library like ICU (International Components for Unicode) for more precise locale-aware comparisons

Keep in mind that these alternatives might introduce additional complexity and performance overhead.

In summary, the benchmark tests two common approaches to case-insensitive string comparison: simple normalization using `toLowerCase()` versus locale-aware comparison using `localeCompare()`. By comparing the performance of these approaches, developers can choose the best solution for their specific use cases.

Javascript: Case insensitive string comparison performance (version: 1)

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

Created: 5 years ago by: Registered User

Go to the latest result

toLowerCase()

localeCompare()

toLowerCase() FAIL

localeCompare() FAIL

Historical Performance Data aggregated from 96 community runs

Desktop Results:

Chrome 87 runs

Firefox 9 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Javascript: Case insensitive string comparison performance (version: 1)

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

Created: 5 years ago by: Registered User

Go to the latest result

toLowerCase()

localeCompare()

toLowerCase() FAIL

localeCompare() FAIL

Historical Performance Data aggregated from 96 community runs

Desktop Results:

Chrome 87 runs

Firefox 9 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

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