Benchmark: find until delimeter: split vs indexOf vs regexp

Script Preparation code:

var str = "1.2.3.4,5.6.7.8"

Tests:

split, shift
str.split(',').shift()
indexOf
var index = str.indexOf(',') str.slice(0, index)
regexp match
var match = str.match(/^(^,)+,/)
regexp exec
var match = /^(^,)+,/.exec(str)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
split, shift
indexOf
regexp match
regexp exec

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.74 Safari/537.36

Browser/OS: Chrome 99 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
split, shift	10349698.0 Ops/sec
indexOf	12466732.0 Ops/sec
regexp match	17973540.0 Ops/sec
regexp exec	18561386.0 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Overview**

The test compares three different approaches to split a string until a specified delimiter:

1. `str.split(',')`
2. `str.indexOf(',')` followed by `str.slice(0, index)`
3. Regular expression matching (`^$(^,)+,$`) using both `match()` and `exec()` methods

**Options being compared**

* **Split**: Using the built-in `split()` method to split the string at the specified delimiter.
* **IndexOf + Slice**: Using the `indexOf()` method to find the index of the first occurrence of the delimiter, and then slicing the original string from the beginning up to that index using `str.slice(0, index)`.
* **Regular Expression (Regexp)**: Using regular expressions to match the specified delimiter. There are two test cases:
	+ `match()`: Uses the `match()` method to search for a match in the string.
	+ `exec()`: Uses the `exec()` method to execute a regular expression search on the string.

**Pros and Cons**

* **Split**: Fast, efficient, and widely supported. However, it may not be suitable for non-delimiter characters (e.g., commas within the string).
* **IndexOf + Slice**: More flexible than Split, as it can handle non-delimiter characters. However, it requires an additional function call to get the index, which might be slower.
* **Regexp**: Powerful and flexible, but also more complex and less intuitive than Split or IndexOf+Slice. It may require more processing power, especially for large strings.

**Other considerations**

* The benchmark does not account for edge cases like empty strings, null/undefined input, or escaped characters.
* The test assumes that the delimiter is a single character; if it's a multi-character string, the results would be different.

**Libraries and special JS features**

* The `match()` method uses regular expressions internally.
* The `exec()` method also uses regular expressions internally, but with slightly different behavior (e.g., no need to compile the regex pattern).
* No special JavaScript features or syntax are used in this benchmark (no ES6+ syntax, async/await, etc.).

**Alternatives**

Other approaches could be considered for splitting a string until a specified delimiter:

* Using `substr()` or `substring()` methods
* Using `replace()` method with a regular expression replacement
* Using a library like Lodash's `split()`

However, the built-in `split()` and `indexOf()` methods are likely to remain popular choices due to their simplicity, efficiency, and widespread support.

Related benchmarks:

find until delimeter: split vs indexOf vs regexp (version: 0)

Comparing performance of: split, shift vs indexOf vs regexp match vs regexp exec

Created: 2 years ago by: Guest

Jump to the latest result

split, shift

indexOf

regexp match

regexp exec

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):