Benchmark: double split vs regex with assign

Script Preparation code:

var str = 'some:text(here)';

Tests:

2xsplit
let [,str2] = str.split(':'); let [str3] = str.split('(');
regex
let [,str4] = str.split(/[:(]/);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
2xsplit
regex

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36

Browser/OS: Chrome 90 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
2xsplit	3071915.2 Ops/sec
regex	4565607.5 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark is designed to compare two approaches for splitting strings in JavaScript:

1. Using `split()` method with multiple arguments (double split).
2. Using regular expressions (regex).

**Script Preparation Code**
```javascript
var str = 'some:text(here)';
```
This line creates a string variable `str` containing the text "some:text(here)".

**Options Being Compared**

There are two main options being compared:

1. **Double Split**: This involves calling the `split()` method twice on the same string, with different arguments each time.
	* First split: `str.split(':')`
	* Second split: `str.split('(')`
2. **Regex**: This involves using a regular expression to split the string.

**Pros and Cons**

**Double Split**

Pros:

* Can be more efficient than regex for simple splits, as it avoids the overhead of creating a regex object.
* May be faster in some cases due to the way JavaScript's `split()` method is implemented.

Cons:

* Requires two separate calls to `split()`, which can increase function call overhead.
* May not handle all edge cases correctly (e.g., escaped characters).

**Regex**

Pros:

* Can handle complex splits with ease, including regular expressions with capturing groups and escapes.
* Often more readable than double split for complex splits.

Cons:

* Can be slower than double split due to the overhead of creating a regex object and executing the pattern.
* May not perform as well on very large strings or with many matches.

**Library Used**

There is no library explicitly mentioned in the benchmark definition. However, some JavaScript engines (like V8) provide optimized implementations for certain string methods, including `split()`.

**Special JS Feature/Syntax**

None are mentioned in this specific benchmark. However, it's worth noting that modern JavaScript features like arrow functions (`=>`), destructuring (`[,...] = ...`) and template literals (`${...}`) may affect the performance of these benchmarks.

**Other Alternatives**

For simple string splits, alternative approaches might include:

1. **Using a custom loop**: Implementing a loop to manually iterate over the string and split it at each desired delimiter.
2. **Using `String.prototype.replace()` with a callback function**: Replacing the entire string with multiple substrings using a callback function.

However, these alternatives would likely have different performance characteristics than the double split and regex approaches being compared in this benchmark.

Related benchmarks:

double split vs regex with assign (version: 0)

Comparing performance of: 2xsplit vs regex

Created: 3 years ago by: Guest

Jump to the latest result

2xsplit

regex

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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