Benchmark: String.split vs String.substring

Script Preparation code:

var str = 'foo.bar'

Tests:

String.split
const [foo] = str.split('.')
String.substring
const foo = str.substring(0, str.indexOf("."))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
String.split
String.substring

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.54 Safari/537.36 Edg/101.0.1210.39

Browser/OS: Chrome 101 on Windows

View result in a separate tab

Test name	Executions per second
String.split	512958.8 Ops/sec
String.substring	638281.6 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is defined by a JSON object that describes two test cases:

1. `String.split vs String.substring`
2. Two individual test cases:
	* `String.split` with the benchmark definition: `const [foo] = str.split('.')`
	* `String.substring` with the benchmark definition: `const foo = str.substring(0, str.indexOf(\".\"))`

**What is being tested?**

The benchmark is testing two different approaches to splitting a string in JavaScript:

1. `String.split()`: This method splits a string into an array of substrings using a specified separator.
2. `String.substring()`: This method extracts a substring from a given string, starting at a specified position and ending at another specified position.

**Options compared**

The benchmark is comparing the performance of these two approaches:

* `String.split()` with and without specifying a separator
* `String.substring()` with and without using `indexOf()` to determine the end position

**Pros and cons of each approach**

1. **`String.split()`**
	* Pros:
		+ More readable and maintainable code, as it returns an array of substrings.
		+ Easier to handle multiple separators or split by default.
	* Cons:
		+ May be slower for large strings due to the overhead of creating an array.
2. **`String.substring()`**
	* Pros:
		+ More efficient for large strings, as it only requires a single substring extraction operation.
		+ Can be faster than `String.split()` for small strings or when using a default separator.
	* Cons:
		+ Less readable and maintainable code, as it returns a single substring.
		+ May require more complex logic to handle multiple separators or split by default.

**Library usage**

The benchmark does not use any specific libraries. However, if the `String` prototype were used, it would be a built-in library.

**Special JS feature or syntax**

There is no special JavaScript feature or syntax being tested in this benchmark. The focus is on comparing the performance of two basic string manipulation methods.

**Other alternatives**

If you wanted to compare other approaches for splitting strings, here are some alternatives:

* `String.prototype.split()` with a default separator (e.g., `const [foo] = str.split('');`)
* Using regular expressions (e.g., `const match = str.match(/\./g); const foo = match[0];`)
* Using a custom implementation using `indexOf()` and indexing into the string
* Using a library like Lodash or Ramda for string manipulation

Keep in mind that these alternatives may have different performance characteristics, trade-offs, and use cases compared to the original benchmark.

Related benchmarks:

String.split vs String.substring (version: 0)

Comparing performance of: String.split vs String.substring

Created: 2 years ago by: Guest

Jump to the latest result

String.split

String.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):