Benchmark: string split vs string substring 2

Script Preparation code:

var s1 = "foo|bar|test";

Tests:

Array.split
var n1 = s1.split('|'); console.log(n1[0])
Substring
var pip = s1.indexOf('|'); console.log(s1.substring(0, pip));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.split
Substring

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0 Safari/605.1.15

Browser/OS: Safari 14 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Array.split	502941.2 Ops/sec
Substring	496206.7 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 and explain what's being tested.

**Benchmark Overview**

The benchmark measures the performance of two approaches to split a string into an array: `Array.prototype.split()` (using a regular expression) versus `String.prototype.indexOf()` followed by `String.prototype.substring()`. The test uses a sample string `s1` containing multiple pipe (`|`) characters, which is the expected separator.

**Options Compared**

The benchmark compares two options:

1. **`Array.prototype.split()`**: This method splits an array into an array of substrings using a specified separator. In this case, the separator is a regular expression that matches one or more pipe (`|`) characters.
2. **`String.prototype.indexOf()` followed by `String.prototype.substring()`**: This approach finds the index of the first occurrence of the separator (in this case, a pipe character) in the string and then extracts the substring before that index.

**Pros and Cons**

* **`Array.prototype.split()`**:
	+ Pros: Efficient and concise way to split an array into substrings.
	+ Cons: May not work as expected if the input is not an array or if the separator is a special regex character.
* **`String.prototype.indexOf()` followed by `String.prototype.substring()`**:
	+ Pros: Can be used with any string type, and the separator can be any character. However, this approach may have performance issues for large strings.
	+ Cons: More complex and less efficient than `Array.prototype.split()`.

**Library Usage**

None in this benchmark.

**Special JS Feature/Syntax**

This benchmark does not use any special JavaScript features or syntax that require explanation.

**Other Alternatives**

If you need to split a string into an array, you can also use:

* `String.prototype.split()` with a custom separator (e.g., `s1.split(",")`)
* A library like Lodash (`lodash.string` module) which provides `str.split()`, `str.indexOf()`, and `str.substring()` methods.

For finding the index of a substring in a larger string, you can use:

* `String.prototype.indexOf()` with an optional second argument (the maximum number of occurrences to find)
* A library like Lodash (`lodash.string` module) which provides `str.indexOf()` method.

Related benchmarks:

string split vs string substring 2 (version: 0)

Comparing performance of: Array.split vs Substring

Created: 4 years ago by: Guest

Jump to the latest result

Array.split

Substring

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):